Merge branch 'master' of git@ettus.sourcerepo.com:ettus/uhd into u1e_uhd

Conflicts:
	host/apps/CMakeLists.txt
	host/lib/usrp/usrp2/usrp2_impl.cpp

57 files changed, 2668 insertions, 1049 deletions

diff --git a/firmware/microblaze/apps/txrx.c b/firmware/microblaze/apps/txrx.c
index 1724284b0..97376ffbd 100644
--- a/firmware/microblaze/apps/txrx.c
+++ b/firmware/microblaze/apps/txrx.c
@@ -153,24 +153,18 @@ static eth_mac_addr_t get_my_eth_mac_addr(void){
 }
 
 static struct ip_addr get_my_ip_addr(void){
-    struct ip_addr addr;
-    addr.addr = 192 << 24 | 168 << 16 | 10 << 8 | 2 << 0;
-    return addr;
+    return *get_ip_addr();
 }
 
-static bool _is_data;
+static void print_ip_addr(const void *t){
+    uint8_t *p = (uint8_t *)t;
+    printf("%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
+}
 
 void handle_udp_data_packet(
     struct socket_address src, struct socket_address dst,
     unsigned char *payload, int payload_len
 ){
-    //forward this data to the dsp when the payload is sufficient
-    //the small payload is used to give the device the udp source port
-    if (payload_len > sizeof(uint32_t)){
-        _is_data = true;
-        return;
-    }
-
     //its a tiny payload, load the fast-path variables
     fp_mac_addr_src = get_my_eth_mac_addr();
     arp_cache_lookup_mac(&src.addr, &fp_mac_addr_dst);
@@ -179,21 +173,13 @@ void handle_udp_data_packet(
     printf("Storing for fast path:\n");
     printf("  source mac addr: ");
     print_mac_addr(fp_mac_addr_src.addr); newline();
-    printf("  source ip addr: %d.%d.%d.%d\n",
-        ((const unsigned char*)&fp_socket_src.addr.addr)[0],
-        ((const unsigned char*)&fp_socket_src.addr.addr)[1],
-        ((const unsigned char*)&fp_socket_src.addr.addr)[2],
-        ((const unsigned char*)&fp_socket_src.addr.addr)[3]
-    );
+    printf("  source ip addr: ");
+    print_ip_addr(&fp_socket_src.addr); newline();
     printf("  source udp port: %d\n", fp_socket_src.port);
     printf("  destination mac addr: ");
     print_mac_addr(fp_mac_addr_dst.addr); newline();
-    printf("  destination ip addr: %d.%d.%d.%d\n",
-        ((const unsigned char*)&fp_socket_dst.addr.addr)[0],
-        ((const unsigned char*)&fp_socket_dst.addr.addr)[1],
-        ((const unsigned char*)&fp_socket_dst.addr.addr)[2],
-        ((const unsigned char*)&fp_socket_dst.addr.addr)[3]
-    );
+    printf("  destination ip addr: ");
+    print_ip_addr(&fp_socket_dst.addr); newline();
     printf("  destination udp port: %d\n", fp_socket_dst.port);
     newline();
 }
@@ -226,14 +212,24 @@ void handle_udp_ctrl_packet(
      ******************************************************************/
     case USRP2_CTRL_ID_GIVE_ME_YOUR_IP_ADDR_BRO:
         ctrl_data_out.id = USRP2_CTRL_ID_THIS_IS_MY_IP_ADDR_DUDE;
-        struct ip_addr ip_addr = get_my_ip_addr();
-        memcpy(&ctrl_data_out.data.ip_addr, &ip_addr, sizeof(ip_addr));
+        memcpy(&ctrl_data_out.data.ip_addr, get_ip_addr(), sizeof(struct ip_addr));
+        break;
+
+    case USRP2_CTRL_ID_HERE_IS_A_NEW_IP_ADDR_BRO:
+        ctrl_data_out.id = USRP2_CTRL_ID_THIS_IS_MY_IP_ADDR_DUDE;
+        set_ip_addr((struct ip_addr *)&ctrl_data_in->data.ip_addr);
+        memcpy(&ctrl_data_out.data.ip_addr, get_ip_addr(), sizeof(struct ip_addr));
         break;
 
     case USRP2_CTRL_ID_GIVE_ME_YOUR_MAC_ADDR_BRO:
         ctrl_data_out.id = USRP2_CTRL_ID_THIS_IS_MY_MAC_ADDR_DUDE;
-        eth_mac_addr_t mac_addr = get_my_eth_mac_addr();
-        memcpy(&ctrl_data_out.data.mac_addr, &mac_addr, sizeof(mac_addr));
+        memcpy(&ctrl_data_out.data.mac_addr, ethernet_mac_addr(), sizeof(eth_mac_addr_t));
+        break;
+
+    case USRP2_CTRL_ID_HERE_IS_A_NEW_MAC_ADDR_BRO:
+        ctrl_data_out.id = USRP2_CTRL_ID_THIS_IS_MY_MAC_ADDR_DUDE;
+        ethernet_set_mac_addr((eth_mac_addr_t *)&ctrl_data_in->data.mac_addr);
+        memcpy(&ctrl_data_out.data.mac_addr, ethernet_mac_addr(), sizeof(eth_mac_addr_t));
         break;
 
     case USRP2_CTRL_ID_GIVE_ME_YOUR_DBOARD_IDS_BRO:
@@ -430,6 +426,8 @@ void handle_udp_ctrl_packet(
      ******************************************************************/
     case USRP2_CTRL_ID_SETUP_THIS_DDC_FOR_ME_BRO:
         dsp_rx_regs->freq = ctrl_data_in->data.ddc_args.freq_word;
+        dsp_rx_regs->scale_iq = ctrl_data_in->data.ddc_args.scale_iq;
+        dsp_rx_regs->rx_mux = 0x00 | (0x01 << 2); //TODO fill in from control
 
         //setup the interp and half band filters
         {
@@ -455,6 +453,8 @@ void handle_udp_ctrl_packet(
     case USRP2_CTRL_ID_CONFIGURE_STREAMING_FOR_ME_BRO:
         time_secs =  ctrl_data_in->data.streaming.secs;
         time_ticks = ctrl_data_in->data.streaming.ticks;
+        streaming_items_per_frame = ctrl_data_in->data.streaming.samples;
+
         if (ctrl_data_in->data.streaming.enabled == 0){
             stop_rx_cmd();
         }
@@ -471,6 +471,7 @@ void handle_udp_ctrl_packet(
     case USRP2_CTRL_ID_SETUP_THIS_DUC_FOR_ME_BRO:
         dsp_tx_regs->freq = ctrl_data_in->data.duc_args.freq_word;
         dsp_tx_regs->scale_iq = ctrl_data_in->data.duc_args.scale_iq;
+        dsp_tx_regs->tx_mux = 0x01; //TODO fill in from control
 
         //setup the interp and half band filters
         {
@@ -493,6 +494,16 @@ void handle_udp_ctrl_packet(
         ctrl_data_out.id = USRP2_CTRL_ID_TOTALLY_SETUP_THE_DUC_DUDE;
         break;
 
+    /*******************************************************************
+     * Time Config
+     ******************************************************************/
+    case USRP2_CTRL_ID_GOT_A_NEW_TIME_FOR_YOU_BRO:
+        sr_time64->imm = (ctrl_data_in->data.time_args.now == 0)? 0 : 1;
+        sr_time64->ticks = ctrl_data_in->data.time_args.ticks;
+        sr_time64->secs = ctrl_data_in->data.time_args.secs; //set this last to latch the regs
+        ctrl_data_out.id = USRP2_CTRL_ID_SWEET_I_GOT_THAT_TIME_DUDE;
+        break;
+
     default:
         ctrl_data_out.id = USRP2_CTRL_ID_HUH_WHAT;
 
@@ -508,15 +519,37 @@ void handle_udp_ctrl_packet(
 static bool
 eth_pkt_inspector(dbsm_t *sm, int bufno)
 {
-  _is_data = false;
-  handle_eth_packet(buffer_ram(bufno), buffer_pool_status->last_line[bufno] - 3);
-  return !_is_data;
+  //point me to the ethernet frame
+  uint32_t *buff = (uint32_t *)buffer_ram(bufno);
+
+  //treat this as fast-path data?
+  // We have to do this operation as fast as possible.
+  // Therefore, we do not check all the headers,
+  // just check that the udp port matches
+  // and that the vrt header is non zero.
+  // In the future, a hardware state machine will do this...
+  if ( //warning! magic numbers approaching....
+      (((buff + ((2 + 14 + 20)/sizeof(uint32_t)))[0] & 0xffff) == USRP2_UDP_DATA_PORT) &&
+      ((buff + ((2 + 14 + 20 + 8)/sizeof(uint32_t)))[0] != 0)
+  ) return false;
+
+  //pass it to the slow-path handler
+  size_t len = buffer_pool_status->last_line[bufno] - 3;
+  handle_eth_packet(buff, len);
+  return true;
 }
 
 //------------------------------------------------------------------
 
-#define VRT_HEADER_WORDS 5
-#define VRT_TRAILER_WORDS 0
+static uint16_t get_vrt_packet_words(void){
+    return streaming_items_per_frame + \
+        USRP2_HOST_RX_VRT_HEADER_WORDS32 + \
+        USRP2_HOST_RX_VRT_TRAILER_WORDS32;
+}
+
+static bool vrt_has_trailer(void){
+    return USRP2_HOST_RX_VRT_TRAILER_WORDS32 > 0;
+}
 
 void
 restart_streaming(void)
@@ -527,10 +560,10 @@ restart_streaming(void)
   sr_rx_ctrl->clear_overrun = 1;			// reset
   sr_rx_ctrl->vrt_header = (0
      | VRTH_PT_IF_DATA_WITH_SID
-     | ((VRT_TRAILER_WORDS)? VRTH_HAS_TRAILER : 0)
+     | (vrt_has_trailer()? VRTH_HAS_TRAILER : 0)
      | VRTH_TSI_OTHER
      | VRTH_TSF_SAMPLE_CNT
-     | (VRT_HEADER_WORDS+streaming_items_per_frame+VRT_TRAILER_WORDS));
+  );
   sr_rx_ctrl->vrt_stream_id = 0;
   sr_rx_ctrl->vrt_trailer = 0;
 
@@ -592,8 +625,9 @@ start_rx_streaming_cmd(void)
   } mem _AL4;
 
   memset(&mem, 0, sizeof(mem));
-  streaming_items_per_frame = (1500)/sizeof(uint32_t) - (DSP_TX_FIRST_LINE + VRT_HEADER_WORDS + VRT_TRAILER_WORDS); //FIXME
-  mem.ctrl_word = (VRT_HEADER_WORDS+streaming_items_per_frame+VRT_TRAILER_WORDS)*sizeof(uint32_t) | 1 << 16;
+  printf("samples per frame: %d\n", streaming_items_per_frame);
+  printf("words in a vrt packet %d\n", get_vrt_packet_words());
+  mem.ctrl_word = get_vrt_packet_words()*sizeof(uint32_t) | 1 << 16;
 
   memcpy_wa(buffer_ram(DSP_RX_BUF_0), &mem, sizeof(mem));
   memcpy_wa(buffer_ram(DSP_RX_BUF_1), &mem, sizeof(mem));
@@ -650,25 +684,6 @@ stop_rx_cmd(void)
 
 }
 
-
-/*static void
-setup_tx()
-{
-  sr_tx_ctrl->clear_state = 1;
-  bp_clear_buf(DSP_TX_BUF_0);
-  bp_clear_buf(DSP_TX_BUF_1);
-
-  int tx_scale = 256;
-  int interp = 32;
-
-  // setup some defaults
-
-  dsp_tx_regs->freq = 0;
-  dsp_tx_regs->scale_iq = (tx_scale << 16) | tx_scale;
-  dsp_tx_regs->interp_rate = interp;
-}*/
-
-
 #if (FW_SETS_SEQNO)
 /*
  * Debugging ONLY.  This will be handled by the tx_protocol_engine.
@@ -710,6 +725,7 @@ main(void)
   putstr("\nTxRx-NEWETH\n");
   print_mac_addr(ethernet_mac_addr()->addr);
   newline();
+  print_ip_addr(get_ip_addr()); newline();
 
   ethernet_register_link_changed_callback(link_changed_callback);
   ethernet_init();
@@ -757,9 +773,9 @@ main(void)
   // tell app_common that this dbsm could be sending to the ethernet
   ac_could_be_sending_to_eth = &dsp_rx_sm;
 
-
-  // program tx registers
-  //setup_tx();
+  sr_tx_ctrl->clear_state = 1;
+  bp_clear_buf(DSP_TX_BUF_0);
+  bp_clear_buf(DSP_TX_BUF_1);
 
   // kick off the state machine
   dbsm_start(&dsp_tx_sm);
diff --git a/firmware/microblaze/include/usrp2_i2c_addr.h b/firmware/microblaze/include/usrp2_i2c_addr.h
index 4111cdd55..46f5a7556 100644
--- a/firmware/microblaze/include/usrp2_i2c_addr.h
+++ b/firmware/microblaze/include/usrp2_i2c_addr.h
@@ -41,6 +41,7 @@
 #define MBOARD_REV_LSB	0x00
 #define	MBOARD_REV_MSB  0x01
 #define	MBOARD_MAC_ADDR 0x02
+#define MBOARD_IP_ADDR  0x0C
 
 
 // format of daughterboard EEPROM
diff --git a/firmware/microblaze/lib/ethernet.c b/firmware/microblaze/lib/ethernet.c
index 5402a6c9f..757a36ce4 100644
--- a/firmware/microblaze/lib/ethernet.c
+++ b/firmware/microblaze/lib/ethernet.c
@@ -271,58 +271,100 @@ ethernet_init(void)
 }
 
 static bool 
-unprogrammed(const eth_mac_addr_t *t)
+unprogrammed(const void *t, size_t len)
 {
   int i;
+  uint8_t *p = (uint8_t *)t;
   bool all_zeros = true;
   bool all_ones =  true;
-  for (i = 0; i < 6; i++){
-    all_zeros &= t->addr[i] == 0x00;
-    all_ones  &= t->addr[i] == 0xff;
+  for (i = 0; i < len; i++){
+    all_zeros &= p[i] == 0x00;
+    all_ones  &= p[i] == 0xff;
   }
   return all_ones | all_zeros;
 }
 
-static int8_t src_addr_initialized = false;
-static eth_mac_addr_t src_addr = {{
+//////////////////// MAC Addr Stuff ///////////////////////
+
+static int8_t src_mac_addr_initialized = false;
+static eth_mac_addr_t src_mac_addr = {{
     0x00, 0x50, 0xC2, 0x85, 0x3f, 0xff
   }};
 
 const eth_mac_addr_t *
 ethernet_mac_addr(void)
 {
-  if (!src_addr_initialized){    // fetch from eeprom
-    src_addr_initialized = true;
+  if (!src_mac_addr_initialized){    // fetch from eeprom
+    src_mac_addr_initialized = true;
 
     // if we're simulating, don't read the EEPROM model, it's REALLY slow
-    if (hwconfig_simulation_p())	
-      return &src_addr;
+    if (hwconfig_simulation_p())
+      return &src_mac_addr;
     
     eth_mac_addr_t tmp;
-    bool ok = eeprom_read(I2C_ADDR_MBOARD, MBOARD_MAC_ADDR, &tmp.addr[0], 6);
-    if (!ok || unprogrammed(&tmp)){
+    bool ok = eeprom_read(I2C_ADDR_MBOARD, MBOARD_MAC_ADDR, &tmp, sizeof(tmp));
+    if (!ok || unprogrammed(&tmp, sizeof(tmp))){
       // use the default
     }
     else
-      src_addr = tmp;
+      src_mac_addr = tmp;
   }
 
-  return &src_addr;
+  return &src_mac_addr;
 }
 
 bool
 ethernet_set_mac_addr(const eth_mac_addr_t *t)
 {
-  bool ok = eeprom_write(I2C_ADDR_MBOARD, MBOARD_MAC_ADDR, &t->addr[0], 6);
+  bool ok = eeprom_write(I2C_ADDR_MBOARD, MBOARD_MAC_ADDR, &t, sizeof(eth_mac_addr_t));
   if (ok){
-    src_addr = *t;
-    src_addr_initialized = true;
+    src_mac_addr = *t;
+    src_mac_addr_initialized = true;
     eth_mac_set_addr(t);
   }
 
   return ok;
 }
 
+//////////////////// IP Addr Stuff ///////////////////////
+
+static int8_t src_ip_addr_initialized = false;
+static struct ip_addr src_ip_addr = {
+    (192 << 24 | 168 << 16 | 10 << 8 | 2 << 0)
+};
+
+
+const struct ip_addr *get_ip_addr(void)
+{
+  if (!src_ip_addr_initialized){    // fetch from eeprom
+    src_ip_addr_initialized = true;
+
+    // if we're simulating, don't read the EEPROM model, it's REALLY slow
+    if (hwconfig_simulation_p())
+      return &src_ip_addr;
+    
+    struct ip_addr tmp;
+    bool ok = eeprom_read(I2C_ADDR_MBOARD, MBOARD_IP_ADDR, &tmp, sizeof(tmp));
+    if (!ok || unprogrammed(&tmp, sizeof(tmp))){
+      // use the default
+    }
+    else
+      src_ip_addr = tmp;
+  }
+
+  return &src_ip_addr;
+}
+
+bool set_ip_addr(const struct ip_addr *t){
+  bool ok = eeprom_write(I2C_ADDR_MBOARD, MBOARD_IP_ADDR, &t, sizeof(struct ip_addr));
+  if (ok){
+    src_ip_addr = *t;
+    src_ip_addr_initialized = true;
+  }
+
+  return ok;
+}
+
 int
 ethernet_check_errors(void)
 {
diff --git a/firmware/microblaze/lib/ethernet.h b/firmware/microblaze/lib/ethernet.h
index 70b7077c6..8c6d8b567 100644
--- a/firmware/microblaze/lib/ethernet.h
+++ b/firmware/microblaze/lib/ethernet.h
@@ -20,6 +20,7 @@
 #define INCLUDED_ETHERNET_H
 
 #include <net/eth_mac_addr.h>
+#include <lwip/ip_addr.h>
 #include <stdbool.h>
 
 typedef void (*ethernet_link_changed_callback_t)(int speed);
@@ -48,6 +49,16 @@ const eth_mac_addr_t *ethernet_mac_addr(void);
  */
 bool ethernet_set_mac_addr(const eth_mac_addr_t *t);
 
+/*!
+ * \returns IP address
+ */
+const struct ip_addr *get_ip_addr(void);
+
+/*!
+ * \brief write ip address to eeprom and begin using it
+ */
+bool set_ip_addr(const struct ip_addr *t);
+
 
 /*
  * \brief read RMON regs and return error mask
diff --git a/firmware/microblaze/lib/net_common.h b/firmware/microblaze/lib/net_common.h
index cfba43412..6cd45bf69 100644
--- a/firmware/microblaze/lib/net_common.h
+++ b/firmware/microblaze/lib/net_common.h
@@ -56,5 +56,4 @@ void send_udp_pkt(int src_port, struct socket_address dst,
 
 void handle_eth_packet(uint32_t *p, size_t nlines);
 
-
 #endif /* INCLUDED_NET_COMMON_H */
diff --git a/host/CMakeLists.txt b/host/CMakeLists.txt
index 30f4789a3..89f035111 100644
--- a/host/CMakeLists.txt
+++ b/host/CMakeLists.txt
@@ -63,6 +63,7 @@ UHD_ADD_OPTIONAL_CXX_COMPILER_FLAG(-ansi      HAVE_ANSI)
 ########################################################################
 FIND_PACKAGE(Boost 1.36 REQUIRED
     date_time
+    filesystem
     program_options
     system
     thread
diff --git a/host/apps/CMakeLists.txt b/host/apps/CMakeLists.txt
index a7068e5a4..58f73fcd6 100644
--- a/host/apps/CMakeLists.txt
+++ b/host/apps/CMakeLists.txt
@@ -17,8 +17,10 @@
 
 ADD_EXECUTABLE(discover_usrps discover_usrps.cpp)
 TARGET_LINK_LIBRARIES(discover_usrps uhd)
+INSTALL(TARGETS discover_usrps RUNTIME DESTINATION ${RUNTIME_DIR})
 
 ADD_EXECUTABLE(usrp1e_load_fpga usrp1e_load_fpga.cpp)
 TARGET_LINK_LIBRARIES(usrp1e_load_fpga uhd)
 
-INSTALL(TARGETS discover_usrps RUNTIME DESTINATION ${RUNTIME_DIR})
+ADD_EXECUTABLE(usrp2_burner usrp2_burner.cpp)
+TARGET_LINK_LIBRARIES(usrp2_burner uhd)
diff --git a/host/apps/discover_usrps.cpp b/host/apps/discover_usrps.cpp
index 7e8c21673..d670d1651 100644
--- a/host/apps/discover_usrps.cpp
+++ b/host/apps/discover_usrps.cpp
@@ -15,7 +15,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include <uhd.hpp>
+#include <uhd/device.hpp>
 #include <uhd/props.hpp>
 #include <boost/program_options.hpp>
 #include <boost/format.hpp>
@@ -63,9 +63,7 @@ int main(int argc, char *argv[]){
         std::cout << "-- USRP Device " << i << std::endl;
         std::cout << "--------------------------------------------------" << std::endl;
         std::cout << device_addrs[i] << std::endl << std::endl;
-        //make each device just to test (TODO: remove this)
-        uhd::device::sptr dev = uhd::device::make(device_addrs[i]);
-        std::cout << wax::cast<std::string>((*dev)[uhd::DEVICE_PROP_MBOARD][uhd::MBOARD_PROP_NAME]) << std::endl;
+        uhd::device::make(device_addrs[i]); //test make
     }
 
     return 0;
diff --git a/host/apps/usrp2_burner.cpp b/host/apps/usrp2_burner.cpp
new file mode 100644
index 000000000..08ec8daf9
--- /dev/null
+++ b/host/apps/usrp2_burner.cpp
@@ -0,0 +1,83 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/usrp/usrp2.hpp>
+#include <uhd/props.hpp>
+#include <boost/program_options.hpp>
+#include <boost/format.hpp>
+#include <iostream>
+
+namespace po = boost::program_options;
+
+int main(int argc, char *argv[]){
+    po::options_description desc("Allowed options");
+    desc.add_options()
+        ("help", "help message")
+        ("addr", po::value<std::string>(), "resolvable network address")
+        ("new-ip", po::value<std::string>(), "new ip address (optional)")
+        ("new-mac", po::value<std::string>(), "new mac address (optional)")
+    ;
+
+    po::variables_map vm;
+    po::store(po::parse_command_line(argc, argv, desc), vm);
+    po::notify(vm); 
+
+    //print the help message
+    if (vm.count("help")){
+        std::cout << boost::format("USRP2 Burner %s") % desc << std::endl;
+        return ~0;
+    }
+
+    //load the options into the address
+    uhd::device_addr_t device_addr;
+    if (vm.count("addr")){
+        device_addr["addr"] = vm["addr"].as<std::string>();
+    }
+    else{
+        std::cerr << "Error: missing addr option" << std::endl;
+        return ~0;
+    }
+
+    //create a usrp2 device
+    uhd::device::sptr u2_dev = uhd::usrp::usrp2::make(device_addr);
+    //FIXME usees the default mboard for now (until the mimo link is supported)
+    wax::obj u2_mb = (*u2_dev)[uhd::DEVICE_PROP_MBOARD];
+
+    //try to set the new ip (if provided)
+    if (vm.count("new-ip")){
+        std::cout << "Burning a new ip address into the usrp2 eeprom:" << std::endl;
+        std::string old_ip = u2_mb[std::string("ip-addr")].as<std::string>();
+        std::cout << boost::format("  Old IP Address: %s") % old_ip << std::endl;
+        std::string new_ip = vm["new-ip"].as<std::string>();
+        std::cout << boost::format("  New IP Address: %s") % new_ip << std::endl;
+        u2_mb[std::string("ip-addr")] = new_ip;
+        std::cout << "  Done" << std::endl;
+    }
+
+    //try to set the new mac (if provided)
+    if (vm.count("new-mac")){
+        std::cout << "Burning a new mac address into the usrp2 eeprom:" << std::endl;
+        std::string old_mac = u2_mb[std::string("mac-addr")].as<std::string>();
+        std::cout << boost::format("  Old MAC Address: %s") % old_mac << std::endl;
+        std::string new_mac = vm["new-mac"].as<std::string>();
+        std::cout << boost::format("  New MAC Address: %s") % new_mac << std::endl;
+        u2_mb[std::string("mac-addr")] = new_mac;
+        std::cout << "  Done" << std::endl;
+    }
+
+    return 0;
+}
diff --git a/host/include/CMakeLists.txt b/host/include/CMakeLists.txt
index 34b705cab..3f7ca2cb7 100644
--- a/host/include/CMakeLists.txt
+++ b/host/include/CMakeLists.txt
@@ -17,8 +17,3 @@
 
 
 ADD_SUBDIRECTORY(uhd)
-
-INSTALL(FILES
-    uhd.hpp
-    DESTINATION ${HEADER_DIR}
-)
diff --git a/host/include/uhd/CMakeLists.txt b/host/include/uhd/CMakeLists.txt
index f4fb96786..522f43afd 100644
--- a/host/include/uhd/CMakeLists.txt
+++ b/host/include/uhd/CMakeLists.txt
@@ -26,6 +26,7 @@ INSTALL(FILES
     gain_handler.hpp
     metadata.hpp
     props.hpp
+    simple_device.hpp
     time_spec.hpp
     utils.hpp
     wax.hpp
diff --git a/host/include/uhd/device.hpp b/host/include/uhd/device.hpp
index ba5337d33..c9d608bcf 100644
--- a/host/include/uhd/device.hpp
+++ b/host/include/uhd/device.hpp
@@ -37,6 +37,19 @@ class device : boost::noncopyable, public wax::obj{
 
 public:
     typedef boost::shared_ptr<device> sptr;
+    typedef boost::function<device_addrs_t(const device_addr_t &)> discover_t;
+    typedef boost::function<sptr(const device_addr_t &)> make_t;
+
+    /*!
+     * Register a device into the discovery and factory system.
+     *
+     * \param discover a function that discovers devices
+     * \param make a factory function that makes a device
+     */
+    static void register_device(
+        const discover_t &discover,
+        const make_t &make
+    );
 
     /*!
      * \brief Discover usrp devices attached to the host.
@@ -70,6 +83,16 @@ public:
     /*!
      * Send a buffer containing IF data with its metadata.
      *
+     * Send handles fragmentation as follows:
+     * If the buffer has more samples than the maximum supported,
+     * the send method will send the maximum number of samples
+     * as supported by the transport and return the number sent.
+     * It is up to the caller to call send again on the un-sent
+     * portions of the buffer, until the buffer is exhausted.
+     *
+     * This is a blocking call and will not return until the number
+     * of samples returned have been read out of the buffer.
+     *
      * \param buff a buffer pointing to some read-only memory
      * \param metadata data describing the buffer's contents
      * \param the type of data loaded in the buffer (32fc, 16sc)
@@ -77,13 +100,31 @@ public:
      */
     virtual size_t send(
         const boost::asio::const_buffer &buff,
-        const metadata_t &metadata,
+        const tx_metadata_t &metadata,
         const std::string &type = "32fc"
     ) = 0;
 
     /*!
      * Receive a buffer containing IF data and its metadata.
      *
+     * Receive handles fragmentation as follows:
+     * If the buffer has insufficient space to hold all samples
+     * that were received in a single packet over-the-wire,
+     * then the buffer will be completely filled and the implementation
+     * will hold a pointer into the remaining portion of the packet.
+     * Subsequent calls will load from the remainder of the packet,
+     * and will flag the metadata to show that this is a fragment.
+     * The next call to receive, after the remainder becomes exahausted,
+     * will perform an over-the-wire receive as usual.
+     *
+     * This is a blocking call and will not return until the number
+     * of samples returned have been written into the buffer.
+     * However, a call to receive may timeout and return zero samples.
+     * The timeout duration is decided by the underlying transport layer.
+     * The caller should assume that the call to receive will not return
+     * immediately when no packets are available to the transport layer,
+     * and that the timeout duration is reasonably tuned for performance.
+     *
      * \param buff the buffer to fill with IF data
      * \param metadata data to fill describing the buffer
      * \param the type of data to fill into the buffer (32fc, 16sc)
@@ -91,7 +132,7 @@ public:
      */
     virtual size_t recv(
         const boost::asio::mutable_buffer &buff,
-        metadata_t &metadata,
+        rx_metadata_t &metadata,
         const std::string &type = "32fc"
     ) = 0;
 };
diff --git a/host/include/uhd/device_addr.hpp b/host/include/uhd/device_addr.hpp
index d02febd6c..ed538453a 100644
--- a/host/include/uhd/device_addr.hpp
+++ b/host/include/uhd/device_addr.hpp
@@ -56,9 +56,9 @@ namespace uhd{
      * \param device_addr a device address instance
      * \return the string representation
      */
-    struct device_addr{
-        static std::string to_string(const device_addr_t &device_addr);
-    };
+    namespace device_addr{
+        std::string to_string(const device_addr_t &device_addr);
+    }
 
 } //namespace uhd
 
diff --git a/host/include/uhd/dict.hpp b/host/include/uhd/dict.hpp
index 1ed28551a..2224a0063 100644
--- a/host/include/uhd/dict.hpp
+++ b/host/include/uhd/dict.hpp
@@ -57,6 +57,14 @@ namespace uhd{
         }
 
         /*!
+         * Get the number of elements in this dict.
+         * \param the number of elements
+         */
+        std::size_t size(void) const{
+            return _map.size();
+        }
+
+        /*!
          * Get a list of the keys in this dict.
          * \return vector of keys
          */
diff --git a/host/include/uhd/gain_handler.hpp b/host/include/uhd/gain_handler.hpp
index 06800315a..a71d63c84 100644
--- a/host/include/uhd/gain_handler.hpp
+++ b/host/include/uhd/gain_handler.hpp
@@ -15,11 +15,9 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include <boost/shared_ptr.hpp>
 #include <uhd/wax.hpp>
-#include <uhd/props.hpp>
+#include <boost/shared_ptr.hpp>
 #include <boost/function.hpp>
-#include <boost/bind.hpp>
 
 #ifndef INCLUDED_UHD_GAIN_HANDLER_HPP
 #define INCLUDED_UHD_GAIN_HANDLER_HPP
@@ -29,29 +27,37 @@ namespace uhd{
 class gain_handler{
 public:
     typedef boost::shared_ptr<gain_handler> sptr;
+    typedef boost::function<bool(const wax::obj &, const wax::obj &)> is_equal_t;
 
-    template <class T> gain_handler(
-        wax::obj *wax_obj_ptr, const T &gain_prop,
-        const T &gain_min_prop, const T &gain_max_prop,
-        const T &gain_step_prop, const T &gain_names_prop
-    ){
-        _wax_obj_ptr = wax_obj_ptr;
-        _gain_prop = gain_prop;
-        _gain_min_prop = gain_min_prop;
-        _gain_max_prop = gain_max_prop;
-        _gain_step_prop = gain_step_prop;
-        _gain_names_prop = gain_names_prop;
-        _is_equal = boost::bind(&gain_handler::is_equal<T>, _1, _2);
-    }
+    /*!
+     * A set of properties for dealing with gains.
+     */
+    struct props_t{
+        wax::obj value, range, names;
+        props_t(void); //default constructor
+    };
 
-    ~gain_handler(void);
+    /*!
+     * Make a new gain handler.
+     * The construction arguments are agnostic to the property type.
+     * It is up to the caller to provide an "is_equal" function that
+     * can tell weather two properties (in a wax obj) are equal.
+     * \param link a link to the wax obj with properties
+     * \param props a struct of properties keys
+     * \param is_equal the function that tests for equal properties
+     */
+    static sptr make(
+        const wax::obj &link,
+        const props_t &props,
+        is_equal_t is_equal
+    );
 
     /*!
      * Intercept gets for overall gain, min, max, step.
      * Ensures that the gain name is valid.
      * \return true for handled, false to pass on
      */
-    bool intercept_get(const wax::obj &key, wax::obj &val);
+    virtual bool intercept_get(const wax::obj &key, wax::obj &val) = 0;
 
     /*!
      * Intercept sets for overall gain.
@@ -59,39 +65,21 @@ public:
      * Ensures that the new gain is within range.
      * \return true for handled, false to pass on
      */
-    bool intercept_set(const wax::obj &key, const wax::obj &val);
-
-private:
-
-    wax::obj     *_wax_obj_ptr;
-    wax::obj      _gain_prop;
-    wax::obj      _gain_min_prop;
-    wax::obj      _gain_max_prop;
-    wax::obj      _gain_step_prop;
-    wax::obj      _gain_names_prop;
+    virtual bool intercept_set(const wax::obj &key, const wax::obj &val) = 0;
 
     /*!
-     * Verify that the key is valid:
-     * If its a named prop for gain, ensure that name is valid.
-     * If the name if not valid, throw a std::invalid_argument.
-     * The name can only be valid if its in the list of gain names.
-     */
-    void _check_key(const wax::obj &key);
-
-    /*
-     * Private interface to test if two wax types are equal:
+     * Function template to test if two wax types are equal:
      * The constructor will bind an instance of this for a specific type.
      * This bound equals functions allows the intercept methods to be non-templated.
      */
     template <class T> static bool is_equal(const wax::obj &a, const wax::obj &b){
         try{
-            return wax::cast<T>(a) == wax::cast<T>(b);
+            return a.as<T>() == b.as<T>();
         }
         catch(const wax::bad_cast &){
             return false;
         }
     }
-    boost::function<bool(const wax::obj &, const wax::obj &)> _is_equal;
 
 };
 
diff --git a/host/include/uhd/metadata.hpp b/host/include/uhd/metadata.hpp
index 70842e7bc..0588ef0ed 100644
--- a/host/include/uhd/metadata.hpp
+++ b/host/include/uhd/metadata.hpp
@@ -23,12 +23,27 @@
 namespace uhd{
 
 /*!
- * Metadata structure for describing the IF data.
- * Includes stream ID, time specification, and burst flags.
+ * RX metadata structure for describing sent IF data.
+ * Includes stream ID, time specification, and fragmentation flags.
  * The receive routines will convert IF data headers into metadata.
+ */
+struct rx_metadata_t{
+    uint32_t stream_id;
+    bool has_stream_id;
+    time_spec_t time_spec;
+    bool has_time_spec;
+    bool is_fragment;
+
+    //default constructor
+    rx_metadata_t(void);
+};
+
+/*!
+ * TX metadata structure for describing received IF data.
+ * Includes stream ID, time specification, and burst flags.
  * The send routines will convert the metadata to IF data headers.
  */
-struct metadata_t{
+struct tx_metadata_t{
     uint32_t stream_id;
     bool has_stream_id;
     time_spec_t time_spec;
@@ -36,14 +51,8 @@ struct metadata_t{
     bool start_of_burst;
     bool end_of_burst;
 
-    metadata_t(void){
-        stream_id = 0;
-        has_stream_id = false;
-        time_spec = time_spec_t();
-        has_time_spec = false;
-        start_of_burst = false;
-        end_of_burst = false;
-    }
+    //default constructor
+    tx_metadata_t(void);
 };
 
 } //namespace uhd
diff --git a/host/include/uhd/props.hpp b/host/include/uhd/props.hpp
index 2b6daf6c5..0dddba647 100644
--- a/host/include/uhd/props.hpp
+++ b/host/include/uhd/props.hpp
@@ -30,6 +30,12 @@ namespace uhd{
     typedef float gain_t;
     typedef double freq_t;
 
+    //gain range tuple (min, max, step)
+    typedef boost::tuple<gain_t, gain_t, gain_t> gain_range_t;
+
+    //freq range tuple (min, max)
+    typedef boost::tuple<freq_t, freq_t> freq_range_t;
+
     //scalar types (have not used yet, dont uncomment until needed)
     //typedef int int_scalar_t;
     //typedef float real_scalar_t;
@@ -51,7 +57,7 @@ namespace uhd{
      */
     inline named_prop_t extract_named_prop(const wax::obj &key, const std::string &name = ""){
         if (key.type() == typeid(named_prop_t)){
-            return wax::cast<named_prop_t>(key);
+            return key.as<named_prop_t>();
         }
         return named_prop_t(key, name);
     }
@@ -65,7 +71,9 @@ namespace uhd{
     enum device_prop_t{
         DEVICE_PROP_NAME,              //ro, std::string
         DEVICE_PROP_MBOARD,            //ro, wax::obj
-        DEVICE_PROP_MBOARD_NAMES       //ro, prop_names_t
+        DEVICE_PROP_MBOARD_NAMES,      //ro, prop_names_t
+        DEVICE_PROP_MAX_RX_SAMPLES,    //ro, size_t
+        DEVICE_PROP_MAX_TX_SAMPLES     //ro, size_t
     };
 
     /*!
@@ -77,7 +85,6 @@ namespace uhd{
     enum mboard_prop_t{
         MBOARD_PROP_NAME,              //ro, std::string
         MBOARD_PROP_OTHERS,            //ro, prop_names_t
-        MBOARD_PROP_MTU,               //ro, size_t
         MBOARD_PROP_CLOCK_RATE,        //ro, freq_t
         MBOARD_PROP_RX_DSP,            //ro, wax::obj
         MBOARD_PROP_RX_DSP_NAMES,      //ro, prop_names_t
@@ -115,16 +122,16 @@ namespace uhd{
     enum dboard_prop_t{
         DBOARD_PROP_NAME,              //ro, std::string
         DBOARD_PROP_SUBDEV,            //ro, wax::obj
-        DBOARD_PROP_SUBDEV_NAMES,      //ro, prop_names_t
-        DBOARD_PROP_CODEC              //ro, wax::obj
-    };
+        DBOARD_PROP_SUBDEV_NAMES       //ro, prop_names_t
+        //DBOARD_PROP_CODEC              //ro, wax::obj //----> not sure, dont have to deal with yet
+    }; 
 
-    /*!
+    /*! ------ not dealing with yet, commented out ------------
     * Possible device codec properties:
     *   A codec is expected to have a rate and gain elements.
     *   Other properties can be discovered through the others prop.
     */
-    enum codec_prop_t{
+    /*enum codec_prop_t{
         CODEC_PROP_NAME,               //ro, std::string
         CODEC_PROP_OTHERS,             //ro, prop_names_t
         CODEC_PROP_GAIN,               //rw, gain_t
@@ -132,8 +139,8 @@ namespace uhd{
         CODEC_PROP_GAIN_MIN,           //ro, gain_t
         CODEC_PROP_GAIN_STEP,          //ro, gain_t
         CODEC_PROP_GAIN_NAMES,         //ro, prop_names_t
-        CODEC_PROP_CLOCK_RATE          //ro, freq_t
-    };
+        //CODEC_PROP_CLOCK_RATE          //ro, freq_t //----> not sure we care to know
+    };*/
 
     /*!
     * Possible device subdev properties
@@ -142,22 +149,19 @@ namespace uhd{
         SUBDEV_PROP_NAME,              //ro, std::string
         SUBDEV_PROP_OTHERS,            //ro, prop_names_t
         SUBDEV_PROP_GAIN,              //rw, gain_t
-        SUBDEV_PROP_GAIN_MAX,          //ro, gain_t
-        SUBDEV_PROP_GAIN_MIN,          //ro, gain_t
-        SUBDEV_PROP_GAIN_STEP,         //ro, gain_t
+        SUBDEV_PROP_GAIN_RANGE,        //ro, gain_range_t
         SUBDEV_PROP_GAIN_NAMES,        //ro, prop_names_t
         SUBDEV_PROP_FREQ,              //rw, freq_t
-        SUBDEV_PROP_FREQ_MAX,          //ro, freq_t
-        SUBDEV_PROP_FREQ_MIN,          //ro, freq_t
+        SUBDEV_PROP_FREQ_RANGE,        //ro, freq_range_t
         SUBDEV_PROP_ANTENNA,           //rw, std::string
         SUBDEV_PROP_ANTENNA_NAMES,     //ro, prop_names_t
         SUBDEV_PROP_ENABLED,           //rw, bool
         SUBDEV_PROP_QUADRATURE,        //ro, bool
         SUBDEV_PROP_IQ_SWAPPED,        //ro, bool
         SUBDEV_PROP_SPECTRUM_INVERTED, //ro, bool
-        SUBDEV_PROP_IS_TX,             //ro, bool
-        SUBDEV_PROP_RSSI,              //ro, gain_t
-        SUBDEV_PROP_BANDWIDTH          //rw, freq_t
+        SUBDEV_PROP_LO_INTERFERES      //ro, bool
+        //SUBDEV_PROP_RSSI,              //ro, gain_t //----> not on all boards, use named prop
+        //SUBDEV_PROP_BANDWIDTH          //rw, freq_t //----> not on all boards, use named prop
     };
 
 } //namespace uhd
diff --git a/host/include/uhd/simple_device.hpp b/host/include/uhd/simple_device.hpp
new file mode 100644
index 000000000..c43155ff2
--- /dev/null
+++ b/host/include/uhd/simple_device.hpp
@@ -0,0 +1,105 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <boost/shared_ptr.hpp>
+#include <boost/utility.hpp>
+#include <uhd/device.hpp>
+#include <vector>
+
+#ifndef INCLUDED_UHD_SIMPLE_DEVICE_HPP
+#define INCLUDED_UHD_SIMPLE_DEVICE_HPP
+
+namespace uhd{
+
+/*!
+ * The tune result struct holds result of a 2-phase tuning:
+ * The struct hold the result of tuning the dboard as
+ * the target and actual intermediate frequency.
+ * The struct hold the result of tuning the DDC/DUC as
+ * the target and actual digital converter frequency.
+ * It also tell us weather or not the spectrum is inverted.
+ */
+struct tune_result_t{
+    double target_inter_freq;
+    double actual_inter_freq;
+    double target_dxc_freq;
+    double actual_dxc_freq;
+    bool spectrum_inverted;
+    tune_result_t(void);
+};
+
+/*!
+ * The simple UHD device class:
+ * A simple device facilitates ease-of-use for most use-case scenarios.
+ * The wrapper provides convenience functions to tune the devices
+ * as well as to set the dboard gains, antennas, and other properties.
+ */
+class simple_device : boost::noncopyable{
+public:
+    typedef boost::shared_ptr<simple_device> sptr;
+    static sptr make(const std::string &args);
+
+    virtual device::sptr get_device(void) = 0;
+
+    virtual std::string get_name(void) = 0;
+
+    /*******************************************************************
+     * Streaming
+     ******************************************************************/
+    virtual void set_streaming(bool enb) = 0;
+    virtual bool get_streaming(void) = 0;
+
+    /*******************************************************************
+     * RX methods
+     ******************************************************************/
+    virtual void set_rx_rate(double rate) = 0;
+    virtual double get_rx_rate(void) = 0;
+    virtual std::vector<double> get_rx_rates(void) = 0;
+
+    virtual tune_result_t set_rx_freq(double freq) = 0;
+    virtual std::vector<double> get_rx_freq_range(void) = 0;
+
+    virtual void set_rx_gain(float gain) = 0;
+    virtual float get_rx_gain(void) = 0;
+    virtual std::vector<float> get_rx_gain_range(void) = 0;
+
+    virtual void set_rx_antenna(const std::string &ant) = 0;
+    virtual std::string get_rx_antenna(void) = 0;
+    virtual std::vector<std::string> get_rx_antennas(void) = 0;
+
+    /*******************************************************************
+     * TX methods
+     ******************************************************************/
+    virtual void set_tx_rate(double rate) = 0;
+    virtual double get_tx_rate(void) = 0;
+    virtual std::vector<double> get_tx_rates(void) = 0;
+
+    virtual tune_result_t set_tx_freq(double freq) = 0;
+    virtual std::vector<double> get_tx_freq_range(void) = 0;
+
+    virtual void set_tx_gain(float gain) = 0;
+    virtual float get_tx_gain(void) = 0;
+    virtual std::vector<float> get_tx_gain_range(void) = 0;
+
+    virtual void set_tx_antenna(const std::string &ant) = 0;
+    virtual std::string get_tx_antenna(void) = 0;
+    virtual std::vector<std::string> get_tx_antennas(void) = 0;
+};
+
+} //namespace uhd
+
+#endif /* INCLUDED_UHD_SIMPLE_DEVICE_HPP */
diff --git a/host/include/uhd/time_spec.hpp b/host/include/uhd/time_spec.hpp
index e5657e555..7e182236b 100644
--- a/host/include/uhd/time_spec.hpp
+++ b/host/include/uhd/time_spec.hpp
@@ -15,6 +15,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
+#include <boost/date_time/posix_time/posix_time.hpp>
 #include <stdint.h>
 
 #ifndef INCLUDED_UHD_TIME_SPEC_HPP
@@ -36,20 +37,22 @@ namespace uhd{
          * Create a time_spec_t that holds a wildcard time.
          * This will have implementation-specific meaning.
          */
-        time_spec_t(void){
-            secs = ~0;
-            ticks = ~0;
-        }
+        time_spec_t(void);
 
         /*!
          * Create a time_spec_t from seconds and ticks.
          * \param new_secs the new seconds
          * \param new_ticks the new ticks (default = 0)
          */
-        time_spec_t(uint32_t new_secs, uint32_t new_ticks = 0){
-            secs = new_secs;
-            ticks = new_ticks;
-        }
+        time_spec_t(uint32_t new_secs, uint32_t new_ticks = 0);
+
+        /*!
+         * Create a time_spec_t from boost posix time.
+         * \param time fine-grained boost posix time
+         * \param tick_rate the rate of ticks per second
+         */
+        time_spec_t(boost::posix_time::ptime time, double tick_rate);
+
     };
 
 } //namespace uhd
diff --git a/host/include/uhd/transport/CMakeLists.txt b/host/include/uhd/transport/CMakeLists.txt
index b786eb945..7f5db2128 100644
--- a/host/include/uhd/transport/CMakeLists.txt
+++ b/host/include/uhd/transport/CMakeLists.txt
@@ -17,6 +17,9 @@
 
 
 INSTALL(FILES
-    udp.hpp
+    smart_buffer.hpp
+    udp_simple.hpp
+    udp_zero_copy.hpp
+    vrt.hpp
     DESTINATION ${HEADER_DIR}/uhd/transport
 )
diff --git a/host/include/uhd/transport/smart_buffer.hpp b/host/include/uhd/transport/smart_buffer.hpp
new file mode 100644
index 000000000..914c02f50
--- /dev/null
+++ b/host/include/uhd/transport/smart_buffer.hpp
@@ -0,0 +1,45 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <boost/asio.hpp>
+#include <boost/utility.hpp>
+#include <boost/shared_ptr.hpp>
+
+#ifndef INCLUDED_UHD_TRANSPORT_SMART_BUFFER_HPP
+#define INCLUDED_UHD_TRANSPORT_SMART_BUFFER_HPP
+
+namespace uhd{ namespace transport{
+
+/*!
+ * A buffer that knows how to free itself:
+ *
+ * This is just the smart buffer interface.
+ * A transport implementation will have its own
+ * internal (custom) smart buffer implementation.
+ *
+ * A smart buffer contains a boost asio const buffer.
+ * On destruction, the buffer contents will be freed.
+ */
+class smart_buffer : boost::noncopyable{
+public:
+    typedef boost::shared_ptr<smart_buffer> sptr;
+    virtual const boost::asio::const_buffer &get(void) const = 0;
+};
+
+}} //namespace
+
+#endif /* INCLUDED_UHD_TRANSPORT_SMART_BUFFER_HPP */
diff --git a/host/include/uhd/transport/udp.hpp b/host/include/uhd/transport/udp_simple.hpp
index 8c6fb096f..0d8fcc5f0 100644
--- a/host/include/uhd/transport/udp.hpp
+++ b/host/include/uhd/transport/udp_simple.hpp
@@ -19,32 +19,43 @@
 #include <boost/utility.hpp>
 #include <boost/shared_ptr.hpp>
 
-#ifndef INCLUDED_UHD_TRANSPORT_UDP_HPP
-#define INCLUDED_UHD_TRANSPORT_UDP_HPP
+#ifndef INCLUDED_UHD_TRANSPORT_UDP_SIMPLE_HPP
+#define INCLUDED_UHD_TRANSPORT_UDP_SIMPLE_HPP
 
 namespace uhd{ namespace transport{
 
-class udp : boost::noncopyable{
+class udp_simple : boost::noncopyable{
 public:
-    typedef boost::shared_ptr<udp> sptr;
+    typedef boost::shared_ptr<udp_simple> sptr;
 
     /*!
-     * Make a new udp transport.
+     * Make a new connected udp transport:
+     * This transport is for sending and receiving
+     * between this host and a single endpoint.
+     * The primary usage for this transport will be control transactions.
+     * The underlying implementation is simple and portable (not fast).
+     *
      * The address will be resolved, it can be a host name or ipv4.
      * The port will be resolved, it can be a port type or number.
+     *
      * \param addr a string representing the destination address
      * \param port a string representing the destination port
-     * \param bcast if true, enable the broadcast option on the socket
      */
-    static sptr make(const std::string &addr, const std::string &port, bool bcast = false);
+    static sptr make_connected(const std::string &addr, const std::string &port);
 
     /*!
-     * Send a vector of buffer (like send_msg).
-     * Blocks until the data is sent.
-     * \param buffs a vector of asio buffers
-     * \return the number of bytes sent
+     * Make a new broadcasting udp transport:
+     * This transport can send udp broadcast datagrams
+     * and receive datagrams from multiple sources.
+     * The primary usage for this transport will be to discover devices.
+     *
+     * The address will be resolved, it can be a host name or ipv4.
+     * The port will be resolved, it can be a port type or number.
+     *
+     * \param addr a string representing the destination address
+     * \param port a string representing the destination port
      */
-    virtual size_t send(const std::vector<boost::asio::const_buffer> &buffs) = 0;
+    static sptr make_broadcast(const std::string &addr, const std::string &port);
 
     /*!
      * Send a single buffer.
@@ -55,22 +66,14 @@ public:
     virtual size_t send(const boost::asio::const_buffer &buff) = 0;
 
     /*!
-     * Receive a buffer. Write into the memory provided.
-     * Returns empty when data is not available.
-     * \param buffs a vector of asio buffers
-     * \return the number of bytes received.
-     */
-    virtual size_t recv(const std::vector<boost::asio::mutable_buffer> &buffs) = 0;
-
-    /*!
-     * Receive a buffer. Write into the memory provided.
-     * Returns empty when data is not available.
+     * Receive into the provided buffer.
+     * Blocks until data is received or a timeout occurs.
      * \param buff a mutable buffer to receive into
-     * \return the number of bytes received.
+     * \return the number of bytes received or zero on timeout
      */
     virtual size_t recv(const boost::asio::mutable_buffer &buff) = 0;
 };
 
 }} //namespace
 
-#endif /* INCLUDED_UHD_TRANSPORT_UDP_HPP */
+#endif /* INCLUDED_UHD_TRANSPORT_UDP_SIMPLE_HPP */
diff --git a/host/include/uhd/transport/udp_zero_copy.hpp b/host/include/uhd/transport/udp_zero_copy.hpp
new file mode 100644
index 000000000..1a8d822fd
--- /dev/null
+++ b/host/include/uhd/transport/udp_zero_copy.hpp
@@ -0,0 +1,76 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/transport/smart_buffer.hpp>
+#include <boost/asio.hpp>
+#include <boost/utility.hpp>
+#include <boost/shared_ptr.hpp>
+
+#ifndef INCLUDED_UHD_TRANSPORT_UDP_ZERO_COPY_HPP
+#define INCLUDED_UHD_TRANSPORT_UDP_ZERO_COPY_HPP
+
+namespace uhd{ namespace transport{
+
+/*!
+ * A zero copy udp transport provides an efficient way to handle data.
+ * by avoiding the extra copy when recv() is called on the socket.
+ * Rather, the zero copy transport gives the caller a memory reference.
+ * The caller informs the transport when it is finished with the reference.
+ *
+ * On linux systems, the zero copy transport can use a kernel packet ring.
+ * If no platform specific solution is available, make returns a boost asio
+ * implementation that wraps the functionality around a standard recv() call.
+ */
+class udp_zero_copy : boost::noncopyable{
+public:
+    typedef boost::shared_ptr<udp_zero_copy> sptr;
+
+    /*!
+     * Make a new zero copy udp transport:
+     * This transport is for sending and receiving
+     * between this host and a single endpoint.
+     * The primary usage for this transport will be data transactions.
+     * The underlying implementation is fast and platform specific.
+     *
+     * The address will be resolved, it can be a host name or ipv4.
+     * The port will be resolved, it can be a port type or number.
+     *
+     * \param addr a string representing the destination address
+     * \param port a string representing the destination port
+     */
+    static sptr make(const std::string &addr, const std::string &port);
+
+    /*!
+     * Send a single buffer.
+     * Blocks until the data is sent.
+     * \param buff single asio buffer
+     * \return the number of bytes sent
+     */
+    virtual size_t send(const boost::asio::const_buffer &buff) = 0;
+
+    /*!
+     * Receive a buffer.
+     * Blocks until data is received or a timeout occurs.
+     * The memory is managed by the implementation.
+     * \return a smart buffer (empty on timeout)
+     */
+    virtual smart_buffer::sptr recv(void) = 0;
+};
+
+}} //namespace
+
+#endif /* INCLUDED_UHD_TRANSPORT_UDP_ZERO_COPY_HPP */
diff --git a/host/include/uhd/transport/vrt.hpp b/host/include/uhd/transport/vrt.hpp
new file mode 100644
index 000000000..1700d2785
--- /dev/null
+++ b/host/include/uhd/transport/vrt.hpp
@@ -0,0 +1,70 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/metadata.hpp>
+#include <cstddef>
+
+#ifndef INCLUDED_UHD_TRANSPORT_VRT_HPP
+#define INCLUDED_UHD_TRANSPORT_VRT_HPP
+
+namespace uhd{ namespace transport{
+
+namespace vrt{
+
+    static const size_t max_header_words32 = 7;
+
+    /*!
+     * Pack a vrt header from metadata.
+     * \param metadata the tx metadata with flags and timestamps
+     * \param header_buff memory to write the packed vrt header
+     * \param num_header_words32 number of words in the vrt header
+     * \param num_payload_words32 the length of the payload
+     * \param num_packet_words32 the length of the packet
+     * \param packet_count the packet count sequence number
+     */
+    void pack(
+        const tx_metadata_t &metadata, //input
+        uint32_t *header_buff,         //output
+        size_t &num_header_words32,    //output
+        size_t num_payload_words32,    //input
+        size_t &num_packet_words32,    //output
+        size_t packet_count            //input
+    );
+
+    /*!
+     * Unpack a vrt header to metadata.
+     * \param metadata the rx metadata with flags and timestamps
+     * \param header_buff memory to read the packed vrt header
+     * \param num_header_words32 number of words in the vrt header
+     * \param num_payload_words32 the length of the payload
+     * \param num_packet_words32 the length of the packet
+     * \param packet_count the packet count sequence number
+     */
+    void unpack(
+        rx_metadata_t &metadata,         //output
+        const uint32_t *header_buff,     //input
+        size_t &num_header_words32,      //output
+        size_t &num_payload_words32,     //output
+        size_t num_packet_words32,       //input
+        size_t &packet_count             //output
+    );
+
+} //namespace vrt
+
+}} //namespace
+
+#endif /* INCLUDED_UHD_TRANSPORT_VRT_HPP */
diff --git a/host/include/uhd/usrp/dboard_base.hpp b/host/include/uhd/usrp/dboard_base.hpp
index b5c0d40ed..9048344ac 100644
--- a/host/include/uhd/usrp/dboard_base.hpp
+++ b/host/include/uhd/usrp/dboard_base.hpp
@@ -56,9 +56,9 @@ protected:
     dboard_id_t get_tx_id(void);
 
 private:
-    std::string        _subdev_name;
+    std::string               _subdev_name;
     dboard_interface::sptr    _dboard_interface;
-    dboard_id_t        _rx_id, _tx_id;
+    dboard_id_t               _rx_id, _tx_id;
 };
 
 /*!
@@ -71,6 +71,7 @@ public:
      * Create a new xcvr dboard object, override in subclasses.
      */
     xcvr_dboard_base(ctor_args_t const&);
+
     virtual ~xcvr_dboard_base(void);
 };
 
diff --git a/host/include/uhd/usrp/dboard_id.hpp b/host/include/uhd/usrp/dboard_id.hpp
index 8e904ff33..34406863d 100644
--- a/host/include/uhd/usrp/dboard_id.hpp
+++ b/host/include/uhd/usrp/dboard_id.hpp
@@ -16,21 +16,20 @@
 //
 
 #include <string>
+#include <stdint.h>
 
 #ifndef INCLUDED_UHD_USRP_DBOARD_ID_HPP
 #define INCLUDED_UHD_USRP_DBOARD_ID_HPP
 
 namespace uhd{ namespace usrp{
 
-enum dboard_id_t{
-    ID_NONE     = 0xffff,
-    ID_BASIC_TX = 0x0000,
-    ID_BASIC_RX = 0x0001
-};
+typedef uint16_t dboard_id_t;
 
-struct dboard_id{
-    static std::string to_string(const dboard_id_t &id);
-};
+static const dboard_id_t ID_NONE = 0xffff;
+
+namespace dboard_id{
+    std::string to_string(const dboard_id_t &id);
+}
 
 }} //namespace
 
diff --git a/host/include/uhd/usrp/dboard_manager.hpp b/host/include/uhd/usrp/dboard_manager.hpp
index 042947ac4..0c32c6dba 100644
--- a/host/include/uhd/usrp/dboard_manager.hpp
+++ b/host/include/uhd/usrp/dboard_manager.hpp
@@ -40,15 +40,17 @@ public:
     typedef dboard_base::sptr(*dboard_ctor_t)(dboard_base::ctor_args_t const&);
 
     /*!
-     * Register subdevices for a given dboard id.
+     * Register a dboard into the system.
      *
      * \param dboard_id the dboard id (rx or tx)
      * \param dboard_ctor the dboard constructor function pointer
+     * \param name the canonical name for the dboard represented
      * \param subdev_names the names of the subdevs on this dboard
      */
-    static void register_subdevs(
+    static void register_dboard(
         dboard_id_t dboard_id,
         dboard_ctor_t dboard_ctor,
+        const std::string &name,
         const prop_names_t &subdev_names
     );
 
diff --git a/host/include/uhd/usrp/usrp2.hpp b/host/include/uhd/usrp/usrp2.hpp
index da7ec595a..b13786546 100644
--- a/host/include/uhd/usrp/usrp2.hpp
+++ b/host/include/uhd/usrp/usrp2.hpp
@@ -29,6 +29,11 @@ class usrp2 : public device{
 public:
     /*!
      * Discover usrp2 devices over the ethernet.
+     *
+     * Recommended key/value pairs for the device hint address:
+     * hint["addr"] = address, where address is a resolvable address
+     * or ip address, which may or may not be a broadcast address.
+     *
      * This static method will be called by the device::discover.
      * \param hint a device addr with the usrp2 address filled in
      * \return a vector of device addresses for all usrp2s found
@@ -37,6 +42,11 @@ public:
 
     /*!
      * Make a usrp2 from a device address.
+     *
+     * Required key/value pairs for the device address:
+     * hint["addr"] = address, where address is a resolvable address
+     * or ip address, which must be the specific address of a usrp2.
+     *
      * \param addr the device address
      * \return a device sptr to a new usrp2
      */
diff --git a/host/include/uhd/utils.hpp b/host/include/uhd/utils.hpp
index 4331aba7e..995cb9926 100644
--- a/host/include/uhd/utils.hpp
+++ b/host/include/uhd/utils.hpp
@@ -15,17 +15,27 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include <uhd/wax.hpp>
-#include <boost/foreach.hpp>
-#include <boost/format.hpp>
-#include <boost/function.hpp>
+#ifndef INCLUDED_UHD_UTILS_HPP
+#define INCLUDED_UHD_UTILS_HPP
+
 #include <stdexcept>
 #include <algorithm>
-#include <vector>
-#include <map>
+#include <boost/format.hpp>
+#include <boost/current_function.hpp>
 
-#ifndef INCLUDED_UHD_UTILS_HPP
-#define INCLUDED_UHD_UTILS_HPP
+/*!
+ * Defines a function that implements the "construct on first use" idiom
+ * \param _t the type definition for the instance
+ * \param _x the name of the defined function
+ * \return a reference to the lazy instance
+ */
+#define STATIC_INSTANCE(_t, _x) static _t &_x(){static _t _x; return _x;}
+
+/*!
+ * Defines a static code block that will be called before main()
+ * \param _x the name of the defined struct (must be unique in file)
+ */
+#define STATIC_BLOCK(_x) static struct _x{_x();}_x;_x::_x()
 
 /*!
  * Useful templated functions and classes that I like to pretend are part of stl
@@ -40,7 +50,9 @@ namespace std{
     };
 
     #define ASSERT_THROW(_x) if (not (_x)) { \
-        throw std::assert_error("Assertion Failed: " + std::string(#_x)); \
+        throw std::assert_error(str(boost::format( \
+            "Assertion Failed:\n  %s:%d\n  %s\n  ---> %s <---" \
+        ) % __FILE__ % __LINE__ % BOOST_CURRENT_FUNCTION % std::string(#_x))); \
     }
 
     template<class T, class InputIterator, class Function>
@@ -52,14 +64,19 @@ namespace std{
         return tmp;
     }
 
+    template<class T, class Iterable, class Function>
+    T reduce(Iterable iterable, Function fcn, T init = 0){
+        return reduce(iterable.begin(), iterable.end(), fcn, init);
+    }
+
     template<class T, class InputIterator>
     bool has(InputIterator first, InputIterator last, const T &elem){
         return last != std::find(first, last, elem);
     }
 
-    template<class T>
-    T sum(const T &a, const T &b){
-        return a + b;
+    template<class T, class Iterable>
+    bool has(const Iterable &iterable, const T &elem){
+        return has(iterable.begin(), iterable.end(), elem);
     }
 
     template<typename T> T signum(T n){
@@ -70,52 +87,43 @@ namespace std{
 
 }//namespace std
 
-/*namespace uhd{
-
-inline void tune(
-    freq_t target_freq,
-    freq_t lo_offset,
-    wax::obj subdev_freq_proxy,
-    bool subdev_quadrature,
-    bool subdev_spectrum_inverted,
-    bool subdev_is_tx,
-    wax::obj dsp_freq_proxy,
-    freq_t dsp_sample_rate
-){
-    // Ask the d'board to tune as closely as it can to target_freq+lo_offset
-    subdev_freq_proxy = target_freq + lo_offset;
-    freq_t inter_freq = wax::cast<freq_t>(subdev_freq_proxy);
-
-    // Calculate the DDC setting that will downconvert the baseband from the
-    // daughterboard to our target frequency.
-    freq_t delta_freq = target_freq - inter_freq;
-    freq_t delta_sign = std::signum(delta_freq);
-    delta_freq *= delta_sign;
-    delta_freq = fmod(delta_freq, dsp_sample_rate);
-    bool inverted = delta_freq > dsp_sample_rate/2.0;
-    freq_t dxc_freq = inverted? (delta_freq - dsp_sample_rate) : (-delta_freq);
-    dxc_freq *= delta_sign;
-
-    // If the spectrum is inverted, and the daughterboard doesn't do
-    // quadrature downconversion, we can fix the inversion by flipping the
-    // sign of the dxc_freq...  (This only happens using the basic_rx board)
-    if (subdev_spectrum_inverted){
-        inverted = not inverted;
-    }
-    if (inverted and not subdev_quadrature){
-        dxc_freq = -dxc_freq;
-        inverted = not inverted;
-    }
-    if (subdev_is_tx){
-        dxc_freq = -dxc_freq;	// down conversion versus up conversion
+#include <boost/format.hpp>
+#include <boost/foreach.hpp>
+#include <boost/lexical_cast.hpp>
+
+namespace uhd{
+
+    /*!
+     * Check that an element is found in a container.
+     * If not, throw a meaningful assertion error.
+     * The "what" in the error will show what is
+     * being set and a list of known good values.
+     *
+     * \param iterable a list of possible settings
+     * \param elem an element that may be in the list
+     * \param what a description of what is being set
+     * \throw assertion_error when elem not in list
+     */
+    template<class T, class Iterable> void assert_has(
+        const Iterable &iterable,
+        const T &elem,
+        const std::string &what = "unknown"
+    ){
+        if (std::has(iterable, elem)) return;
+        std::string possible_values = "";
+        BOOST_FOREACH(T e, iterable){
+            if (e != iterable.begin()[0]) possible_values += ", ";
+            possible_values += boost::lexical_cast<std::string>(e);
+        }
+        throw std::assert_error(str(boost::format(
+                "Error: %s is not a valid %s. "
+                "Possible values are: [%s]."
+            )
+            % boost::lexical_cast<std::string>(elem)
+            % what % possible_values
+        ));
     }
 
-    dsp_freq_proxy = dxc_freq;
-    //freq_t actual_dxc_freq = wax::cast<freq_t>(dsp_freq_proxy);
-
-    //return some kind of tune result tuple/struct
-}
-
-} //namespace uhd*/
+}//namespace uhd
 
 #endif /* INCLUDED_UHD_UTILS_HPP */
diff --git a/host/include/uhd/wax.hpp b/host/include/uhd/wax.hpp
index 1d5054351..0291a06b7 100644
--- a/host/include/uhd/wax.hpp
+++ b/host/include/uhd/wax.hpp
@@ -19,32 +19,35 @@
 #define INCLUDED_WAX_HPP
 
 #include <boost/any.hpp>
-#include <iostream>
 
 /*!
  * WAX - it's a metaphor!
  *
- * The WAX framework allows object to have generic/anyobj properties.
+ * The WAX framework allows an object to have generic/anyobj properties.
  * These properties can be addressed through generic/anyobj identifiers.
- * A property of a WAX object may even be another WAX object.
  *
- * When a property is a WAX object, the returned value must be an obj pointer.
- * A WAX object provides two objs of pointers: obj::ptr and obj::sptr.
- * The choice of pointer vs smart pointer depends on the owner of the memory.
+ * The WAX object itself is an anytype container much like boost::any.
+ * To retrieve the value of the appropriate type, use my_obj.as<type>().
  *
  * Proprties may be referenced though the [] overloaded operator.
  * The [] operator returns a special proxy that allows for assigment.
  * Also, the [] operators may be chained as in the folowing examples:
- *   my_obj[prop1][prop2][prop3] = value
- *   value = my_obj[prop1][prop2][prop3]
+ *   my_obj[prop1][prop2][prop3] = value;
+ *   value = my_obj[prop1][prop2][prop3].as<type>();
  *
- * Any value returned from an access operation is of wax::obj.
- * To use this value, it must be cast with wax::cast<new_obj>(value).
+ * Property nesting occurs when a WAX object gets another object's link.
+ * This special link is obtained through a call to my_obj.get_link().
  */
 
 namespace wax{
 
     /*!
+     * The wax::bad cast will be thrown when
+     * cast is called with the wrong typeid.
+     */
+    typedef boost::bad_any_cast bad_cast;
+
+    /*!
      * WAX object base class:
      *
      * A wax obj has two major purposes:
@@ -124,6 +127,17 @@ namespace wax{
          */
         const std::type_info & type(void) const;
 
+        /*!
+         * Cast this obj into the desired type.
+         * Usage: myobj.as<type>()
+         *
+         * \return an object of the desired type
+         * \throw wax::bad_cast when the cast fails
+         */
+        template<class T> T as(void) const{
+            return boost::any_cast<T>(resolve());
+        }
+
     private:
         //private interface (override in subclasses)
         virtual void get(const obj &, obj &);
@@ -137,31 +151,12 @@ namespace wax{
          * \return a boost any type with contents
          */
         boost::any resolve(void) const;
-        template<class T> friend T cast(const obj &);
 
         //private contents of this obj
         boost::any _contents;
 
     };
 
-    /*!
-     * The wax::bad cast will be thrown when
-     * cast is called with the wrong typeid.
-     */
-    typedef boost::bad_any_cast bad_cast;
-
-    /*!
-     * Cast a wax::obj into the desired obj.
-     * Usage wax::cast<new_obj>(my_value).
-     *
-     * \param val the obj to cast
-     * \return an object of the desired type
-     * \throw wax::bad_cast when the cast fails
-     */
-    template<class T> T cast(const obj &val){
-        return boost::any_cast<T>(val.resolve());
-    }
-
 } //namespace wax
 
 #endif /* INCLUDED_WAX_HPP */
diff --git a/host/lib/CMakeLists.txt b/host/lib/CMakeLists.txt
index 33314e729..ca00c3597 100644
--- a/host/lib/CMakeLists.txt
+++ b/host/lib/CMakeLists.txt
@@ -22,12 +22,14 @@ SET(libuhd_sources
     device.cpp
     device_addr.cpp
     gain_handler.cpp
-    uhd.cpp
+    metadata.cpp
+    simple_device.cpp
+    time_spec.cpp
     wax.cpp
-    transport/udp.cpp
+    transport/udp_simple.cpp
+    transport/vrt.cpp
     usrp/dboard/basic.cpp
     usrp/dboard_base.cpp
-    usrp/dboard_id.cpp
     usrp/dboard_interface.cpp
     usrp/dboard_manager.cpp
     usrp/usrp2/dboard_impl.cpp
@@ -39,6 +41,13 @@ SET(libuhd_sources
 )
 
 ########################################################################
+# Conditionally add the udp sources
+########################################################################
+LIST(APPEND libuhd_sources
+    transport/udp_zero_copy_none.cpp
+)
+
+########################################################################
 # Conditionally add the usrp1e sources
 ########################################################################
 INCLUDE(CheckIncludeFiles)
diff --git a/host/lib/device.cpp b/host/lib/device.cpp
index 82052708a..a87ba83eb 100644
--- a/host/lib/device.cpp
+++ b/host/lib/device.cpp
@@ -15,40 +15,22 @@
 // asize_t with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include <uhd/usrp/usrp1e.hpp>
-#include <uhd/usrp/usrp2.hpp>
+#include <uhd/device.hpp>
 #include <uhd/dict.hpp>
 #include <uhd/utils.hpp>
 #include <boost/foreach.hpp>
 #include <boost/format.hpp>
 #include <boost/weak_ptr.hpp>
 #include <boost/functional/hash.hpp>
+#include <boost/tuple/tuple.hpp>
 #include <stdexcept>
 #include <algorithm>
 
 using namespace uhd;
 
-/*!
- * Create a new device from a device address.
- * Based on the address, call the appropriate make functions.
- * \param dev_addr the device address
- * \return a smart pointer to a device
- */
-static device::sptr make_device(const device_addr_t &dev_addr){
-
-    //create a usrp1e
-    if (dev_addr["type"] == "usrp1e"){
-        return usrp::usrp1e::make(dev_addr);
-    }
-
-    //create a usrp2
-    if (dev_addr["type"] == "usrp2"){
-        return usrp::usrp2::make(dev_addr);
-    }
-
-    throw std::runtime_error("cant make a device");
-}
-
+/***********************************************************************
+ * Helper Functions
+ **********************************************************************/
 /*!
  * Make a device hash that maps 1 to 1 with a device address.
  * The hash will be used to identify created devices.
@@ -72,19 +54,34 @@ static size_t hash_device_addr(
 }
 
 /***********************************************************************
+ * Registration
+ **********************************************************************/
+typedef boost::tuple<device::discover_t, device::make_t> dev_fcn_reg_t;
+
+// instantiate the device function registry container
+STATIC_INSTANCE(std::vector<dev_fcn_reg_t>, get_dev_fcn_regs)
+
+void device::register_device(
+    const discover_t &discover,
+    const make_t &make
+){
+    //std::cout << "registering device" << std::endl;
+    get_dev_fcn_regs().push_back(dev_fcn_reg_t(discover, make));
+}
+
+/***********************************************************************
  * Discover
  **********************************************************************/
 device_addrs_t device::discover(const device_addr_t &hint){
     device_addrs_t device_addrs;
 
-    //discover the usrp1es
-    std::vector<device_addr_t> usrp2_addrs = usrp::usrp1e::discover(hint);
-    device_addrs.insert(device_addrs.begin(), usrp2_addrs.begin(), usrp2_addrs.end());
-
-    //discover the usrp2s
-    if (hint.has_key("addr")){
-        std::vector<device_addr_t> usrp2_addrs = usrp::usrp2::discover(hint);
-        device_addrs.insert(device_addrs.begin(), usrp2_addrs.begin(), usrp2_addrs.end());
+    BOOST_FOREACH(dev_fcn_reg_t fcn, get_dev_fcn_regs()){
+        device_addrs_t discovered_addrs = fcn.get<0>()(hint);
+        device_addrs.insert(
+            device_addrs.begin(),
+            discovered_addrs.begin(),
+            discovered_addrs.end()
+        );
     }
 
     return device_addrs;
@@ -94,24 +91,38 @@ device_addrs_t device::discover(const device_addr_t &hint){
  * Make
  **********************************************************************/
 device::sptr device::make(const device_addr_t &hint, size_t which){
-    std::vector<device_addr_t> device_addrs = discover(hint);
+    typedef boost::tuple<device_addr_t, make_t> dev_addr_make_t;
+    std::vector<dev_addr_make_t> dev_addr_makers;
+
+    BOOST_FOREACH(dev_fcn_reg_t fcn, get_dev_fcn_regs()){
+        BOOST_FOREACH(device_addr_t dev_addr, fcn.get<0>()(hint)){
+            //copy keys that were in hint but not in dev_addr
+            //this way, we can pass additional transport arguments
+            BOOST_FOREACH(std::string key, hint.get_keys()){
+                if (not dev_addr.has_key(key)) dev_addr[key] = hint[key];
+            }
+            //append the discovered address and its factory function
+            dev_addr_makers.push_back(dev_addr_make_t(dev_addr, fcn.get<1>()));
+        }
+    }
 
     //check that we found any devices
-    if (device_addrs.size() == 0){
+    if (dev_addr_makers.size() == 0){
         throw std::runtime_error(str(
             boost::format("No devices found for %s") % device_addr::to_string(hint)
         ));
     }
 
     //check that the which index is valid
-    if (device_addrs.size() <= which){
+    if (dev_addr_makers.size() <= which){
         throw std::runtime_error(str(
             boost::format("No device at index %d for %s") % which % device_addr::to_string(hint)
         ));
     }
 
     //create a unique hash for the device address
-    device_addr_t dev_addr = device_addrs.at(which);
+    device_addr_t dev_addr; make_t maker;
+    boost::tie(dev_addr, maker) = dev_addr_makers.at(which);
     size_t dev_hash = hash_device_addr(dev_addr);
     //std::cout << boost::format("Hash: %u") % dev_hash << std::endl;
 
@@ -126,7 +137,7 @@ device::sptr device::make(const device_addr_t &hint, size_t which){
     }
     //create and register a new device
     catch(const std::assert_error &e){
-        device::sptr dev = make_device(dev_addr);
+        device::sptr dev = maker(dev_addr);
         hash_to_device[dev_hash] = dev;
         return dev;
     }
diff --git a/host/lib/gain_handler.cpp b/host/lib/gain_handler.cpp
index b03d5bda2..847bc0528 100644
--- a/host/lib/gain_handler.cpp
+++ b/host/lib/gain_handler.cpp
@@ -17,6 +17,7 @@
 
 #include <uhd/gain_handler.hpp>
 #include <uhd/utils.hpp>
+#include <uhd/props.hpp>
 #include <boost/assign/list_of.hpp>
 #include <boost/foreach.hpp>
 #include <boost/format.hpp>
@@ -25,143 +26,156 @@
 using namespace uhd;
 
 /***********************************************************************
- * Helper functions and macros
+ * gain handler implementation interface
  **********************************************************************/
-#define GET_PROP_NAMES() \
-    wax::cast<prop_names_t>((*_wax_obj_ptr)[_gain_names_prop])
-
-/*!
- * Helper function to simplify getting a named gain (also min, max, step).
- */
-static gain_t get_named_gain(wax::obj *wax_obj_ptr, wax::obj prop, std::string name){
-    return wax::cast<gain_t>((*wax_obj_ptr)[named_prop_t(prop, name)]);
+class gain_handler_impl : public gain_handler{
+public:
+    gain_handler_impl(
+        const wax::obj &link,
+        const props_t &props,
+        is_equal_t is_equal
+    );
+    ~gain_handler_impl(void);
+    bool intercept_get(const wax::obj &key, wax::obj &val);
+    bool intercept_set(const wax::obj &key, const wax::obj &val);
+
+private:
+    wax::obj     _link;
+    props_t _props;
+    is_equal_t   _is_equal;
+
+    prop_names_t get_gain_names(void);
+    gain_t get_overall_gain_val(void);
+    gain_range_t get_overall_gain_range(void);
+    template <class T> T get_named_prop(const wax::obj &prop, const std::string &name){
+        return _link[named_prop_t(prop, name)].as<T>();
+    }
+};
+
+/***********************************************************************
+ * the make function
+ **********************************************************************/
+gain_handler::sptr gain_handler::make(
+    const wax::obj &link,
+    const props_t &props,
+    is_equal_t is_equal
+){
+    return sptr(new gain_handler_impl(link, props, is_equal));
 }
 
 /***********************************************************************
- * Class methods of gain handler
+ * gain handler implementation methods
  **********************************************************************/
-gain_handler::~gain_handler(void){
+gain_handler::props_t::props_t(void){
     /* NOP */
 }
 
-void gain_handler::_check_key(const wax::obj &key_){
-    wax::obj key; std::string name;
-    boost::tie(key, name) = extract_named_prop(key_);
-    
-    try{
-        //only handle non wildcard names
-        ASSERT_THROW(name != "");
-
-        //only handle these gain props
-        ASSERT_THROW(
-            _is_equal(key, _gain_prop)     or
-            _is_equal(key, _gain_min_prop) or
-            _is_equal(key, _gain_max_prop) or
-            _is_equal(key, _gain_step_prop)
-        );
-
-        //check that the name is allowed
-        prop_names_t prop_names = GET_PROP_NAMES();
-        ASSERT_THROW(not std::has(prop_names.begin(), prop_names.end(), name));
-
-        //if we get here, throw an exception
-        throw std::invalid_argument(str(
-            boost::format("Unknown gain name %s") % name
-        ));
-    }
-    catch(const std::assert_error &){}
+gain_handler_impl::gain_handler_impl(
+    const wax::obj &link,
+    const props_t &props,
+    is_equal_t is_equal
+){
+    _link = link;
+    _props = props;
+    _is_equal = is_equal;
 }
 
-static gain_t gain_max(gain_t a, gain_t b){
-    return std::max(a, b);
+gain_handler_impl::~gain_handler_impl(void){
+    /* NOP */
 }
-static gain_t gain_sum(gain_t a, gain_t b){
-    return std::sum(a, b);
+
+prop_names_t gain_handler_impl::get_gain_names(void){
+    return _link[_props.names].as<prop_names_t>();
 }
 
-bool gain_handler::intercept_get(const wax::obj &key, wax::obj &val){
-    _check_key(key); //verify the key
-
-    std::vector<wax::obj> gain_props = boost::assign::list_of
-        (_gain_prop)(_gain_min_prop)(_gain_max_prop)(_gain_step_prop);
-
-    /*!
-     * Handle getting overall gains when a name is not specified.
-     * For the gain props below, set the overall value and return true. 
-     */
-    BOOST_FOREACH(wax::obj prop_key, gain_props){
-        if (_is_equal(key, prop_key)){
-            //form the gains vector from the props vector
-            prop_names_t prop_names = GET_PROP_NAMES();
-            std::vector<gain_t> gains(prop_names.size());
-            std::transform(
-                prop_names.begin(), prop_names.end(), gains.begin(),
-                boost::bind(get_named_gain, _wax_obj_ptr, key, _1)
-            );
-
-            //reduce across the gain vector
-            if (_is_equal(key, _gain_step_prop)){
-                val = std::reduce<gain_t>(gains.begin(), gains.end(), gain_max);
-            }
-            else{
-                val = std::reduce<gain_t>(gains.begin(), gains.end(), gain_sum);
-            }
-            return true;
-        }
+gain_t gain_handler_impl::get_overall_gain_val(void){
+    gain_t gain_val = 0;
+    BOOST_FOREACH(std::string name, get_gain_names()){
+        gain_val += get_named_prop<gain_t>(_props.value, name);
     }
+    return gain_val;
+}
 
-    return false;
+gain_range_t gain_handler_impl::get_overall_gain_range(void){
+    gain_t gain_min = 0, gain_max = 0, gain_step = 0;
+    BOOST_FOREACH(std::string name, get_gain_names()){
+        gain_t gain_min_tmp, gain_max_tmp, gain_step_tmp;
+        boost::tie(gain_min_tmp, gain_max_tmp, gain_step_tmp) = \
+            get_named_prop<gain_range_t>(_props.range, name);
+        gain_min += gain_min_tmp;
+        gain_max += gain_max_tmp;
+        gain_step = std::max(gain_step, gain_step_tmp);
+    }
+    return gain_range_t(gain_min, gain_max, gain_step);
 }
 
-bool gain_handler::intercept_set(const wax::obj &key_, const wax::obj &val){
-    _check_key(key_); //verify the key
+/***********************************************************************
+ * gain handler implementation get method
+ **********************************************************************/
+bool gain_handler_impl::intercept_get(const wax::obj &key_, wax::obj &val){
+    wax::obj key; std::string name;
+    boost::tie(key, name) = extract_named_prop(key_);
+
+    //not a wildcard... dont handle (but check name)
+    if (name != ""){
+        assert_has(get_gain_names(), name, "gain name");
+        return false;
+    }
+
+    if (_is_equal(key, _props.value)){
+        val = get_overall_gain_val();
+        return true;
+    }
+
+    if (_is_equal(key, _props.range)){
+        val = get_overall_gain_range();
+        return true;
+    }
+
+    return false; //not handled
+}
 
+/***********************************************************************
+ * gain handler implementation set method
+ **********************************************************************/
+bool gain_handler_impl::intercept_set(const wax::obj &key_, const wax::obj &val){
     wax::obj key; std::string name;
     boost::tie(key, name) = extract_named_prop(key_);
 
-    /*!
-     * Verify that a named gain component is in range.
-     */
-    try{
-        //only handle the gain props
-        ASSERT_THROW(_is_equal(key, _gain_prop));
-
-        //check that the gain is in range
-        gain_t gain = wax::cast<gain_t>(val);
-        gain_t gain_min = get_named_gain(_wax_obj_ptr, _gain_min_prop,  name);
-        gain_t gain_max = get_named_gain(_wax_obj_ptr, _gain_max_prop,  name);
-        ASSERT_THROW(gain > gain_max or gain < gain_min);
-
-        //if we get here, throw an exception
-        throw std::range_error(str(
-            boost::format("gain %s is out of range of (%f, %f)") % name % gain_min % gain_max
+    //not a gain value key... dont handle
+    if (not _is_equal(key, _props.value)) return false;
+
+    gain_t gain_val = val.as<gain_t>();
+
+    //not a wildcard... dont handle (but check name and range)
+    if (name != ""){
+        assert_has(get_gain_names(), name, "gain name");
+        gain_t gain_min, gain_max, gain_step;
+        boost::tie(gain_min, gain_max, gain_step) = \
+            get_named_prop<gain_range_t>(_props.range, name);
+        if (gain_val > gain_max or gain_val < gain_min) throw std::range_error(str(
+            boost::format("A value of %f for gain %s is out of range of (%f, %f)")
+            % gain_val % name % gain_min % gain_max
         ));
+        return false;
     }
-    catch(const std::assert_error &){}
-
-    /*!
-     * Handle setting the overall gain.
-     */
-    if (_is_equal(key, _gain_prop) and name == ""){
-        gain_t gain = wax::cast<gain_t>(val);
-        prop_names_t prop_names = GET_PROP_NAMES();
-        BOOST_FOREACH(std::string name, prop_names){
-            //get the min, max, step for this gain name
-            gain_t gain_min  = get_named_gain(_wax_obj_ptr, _gain_min_prop,  name);
-            gain_t gain_max  = get_named_gain(_wax_obj_ptr, _gain_max_prop,  name);
-            gain_t gain_step = get_named_gain(_wax_obj_ptr, _gain_step_prop, name);
-
-            //clip g to be within the allowed range
-            gain_t g = std::min(std::max(gain, gain_min), gain_max);
-            //set g to be a multiple of the step size
-            g -= fmod(g, gain_step);
-            //set g to be the new gain
-            (*_wax_obj_ptr)[named_prop_t(_gain_prop, name)] = g;
-            //subtract g out of the total gain left to apply
-            gain -= g;
-        }
-        return true;
+
+    //set the overall gain
+    BOOST_FOREACH(std::string name, get_gain_names()){
+        //get the min, max, step for this gain name
+        gain_t gain_min, gain_max, gain_step;
+        boost::tie(gain_min, gain_max, gain_step) = \
+            get_named_prop<gain_range_t>(_props.range, name);
+
+        //clip g to be within the allowed range
+        gain_t g = std::min(std::max(gain_val, gain_min), gain_max);
+        //set g to be a multiple of the step size
+        g -= fmod(g, gain_step);
+        //set g to be the new gain
+        _link[named_prop_t(_props.value, name)] = g;
+        //subtract g out of the total gain left to apply
+        gain_val -= g;
     }
 
-    return false;
+    return true;
 }
diff --git a/host/include/uhd.hpp b/host/lib/metadata.cpp
index ee8c13dfe..40fdb7c73 100644
--- a/host/include/uhd.hpp
+++ b/host/lib/metadata.cpp
@@ -15,10 +15,23 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#ifndef INCLUDED_UHD_HPP
-#define INCLUDED_UHD_HPP
+#include <uhd/metadata.hpp>
 
-//include convenience headers
-#include <uhd/device.hpp>
+using namespace uhd;
 
-#endif /* INCLUDED_UHD_HPP */
+rx_metadata_t::rx_metadata_t(void){
+    stream_id = 0;
+    has_stream_id = false;
+    time_spec = time_spec_t();
+    has_time_spec = false;
+    is_fragment = false;
+}
+
+tx_metadata_t::tx_metadata_t(void){
+    stream_id = 0;
+    has_stream_id = false;
+    time_spec = time_spec_t();
+    has_time_spec = false;
+    start_of_burst = false;
+    end_of_burst = false;
+}
diff --git a/host/lib/simple_device.cpp b/host/lib/simple_device.cpp
new file mode 100644
index 000000000..62a38cb79
--- /dev/null
+++ b/host/lib/simple_device.cpp
@@ -0,0 +1,301 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/simple_device.hpp>
+#include <uhd/device.hpp>
+#include <uhd/utils.hpp>
+#include <uhd/props.hpp>
+#include <boost/algorithm/string.hpp>
+#include <boost/algorithm/string/trim.hpp>
+#include <boost/foreach.hpp>
+#include <boost/format.hpp>
+#include <stdexcept>
+
+using namespace uhd;
+
+tune_result_t::tune_result_t(void){
+    /* NOP */
+}
+
+/***********************************************************************
+ * Tune Helper Function
+ **********************************************************************/
+static tune_result_t tune(
+    double target_freq,
+    double lo_offset,
+    wax::obj subdev,
+    wax::obj dxc,
+    bool is_tx
+){
+    wax::obj subdev_freq_proxy = subdev[SUBDEV_PROP_FREQ];
+    bool subdev_quadrature = subdev[SUBDEV_PROP_QUADRATURE].as<bool>();
+    bool subdev_spectrum_inverted = subdev[SUBDEV_PROP_SPECTRUM_INVERTED].as<bool>();
+    wax::obj dxc_freq_proxy = dxc[std::string("freq")];
+    double dxc_sample_rate = dxc[std::string("rate")].as<double>();
+
+    // Ask the d'board to tune as closely as it can to target_freq+lo_offset
+    double target_inter_freq = target_freq + lo_offset;
+    subdev_freq_proxy = target_inter_freq;
+    double actual_inter_freq = subdev_freq_proxy.as<double>();
+
+    // Calculate the DDC setting that will downconvert the baseband from the
+    // daughterboard to our target frequency.
+    double delta_freq = target_freq - actual_inter_freq;
+    double delta_sign = std::signum(delta_freq);
+    delta_freq *= delta_sign;
+    delta_freq = fmod(delta_freq, dxc_sample_rate);
+    bool inverted = delta_freq > dxc_sample_rate/2.0;
+    double target_dxc_freq = inverted? (delta_freq - dxc_sample_rate) : (-delta_freq);
+    target_dxc_freq *= delta_sign;
+
+    // If the spectrum is inverted, and the daughterboard doesn't do
+    // quadrature downconversion, we can fix the inversion by flipping the
+    // sign of the dxc_freq...  (This only happens using the basic_rx board)
+    if (subdev_spectrum_inverted){
+        inverted = not inverted;
+    }
+    if (inverted and not subdev_quadrature){
+        target_dxc_freq *= -1.0;
+        inverted = not inverted;
+    }
+    // down conversion versus up conversion, fight!
+    // your mother is ugly and your going down...
+    target_dxc_freq *= (is_tx)? -1.0 : +1.0;
+
+    dxc_freq_proxy = target_dxc_freq;
+    double actual_dxc_freq = dxc_freq_proxy.as<double>();
+
+    //return some kind of tune result tuple/struct
+    tune_result_t tune_result;
+    tune_result.target_inter_freq = target_inter_freq;
+    tune_result.actual_inter_freq = actual_inter_freq;
+    tune_result.target_dxc_freq = target_dxc_freq;
+    tune_result.actual_dxc_freq = actual_dxc_freq;
+    tune_result.spectrum_inverted = inverted;
+    return tune_result;
+}
+
+/***********************************************************************
+ * Helper Functions
+ **********************************************************************/
+static std::string trim(const std::string &in){
+    return boost::algorithm::trim_copy(in);
+}
+
+device_addr_t args_to_device_addr(const std::string &args){
+    device_addr_t addr;
+
+    //split the args at the semi-colons
+    std::vector<std::string> pairs;
+    boost::split(pairs, args, boost::is_any_of(";"));
+    BOOST_FOREACH(std::string pair, pairs){
+        if (trim(pair) == "") continue;
+
+        //split the key value pairs at the equals
+        std::vector<std::string> key_val;
+        boost::split(key_val, pair, boost::is_any_of("="));
+        if (key_val.size() != 2) throw std::runtime_error("invalid args string: "+args);
+        addr[trim(key_val[0])] = trim(key_val[1]);
+    }
+
+    return addr;
+}
+
+static std::vector<double> get_xx_rates(wax::obj decerps, wax::obj rate){
+    std::vector<double> rates;
+    BOOST_FOREACH(size_t decerp, decerps.as<std::vector<size_t> >()){
+        rates.push_back(rate.as<double>()/decerp);
+    }
+    return rates;
+}
+
+/***********************************************************************
+ * Simple Device Implementation
+ **********************************************************************/
+class simple_device_impl : public simple_device{
+public:
+    simple_device_impl(const device_addr_t &addr){
+        _dev = device::make(addr);
+        _mboard = (*_dev)[DEVICE_PROP_MBOARD];
+        _rx_ddc = _mboard[named_prop_t(MBOARD_PROP_RX_DSP, "ddc0")];
+        _tx_duc = _mboard[named_prop_t(MBOARD_PROP_TX_DSP, "duc0")];
+        _rx_subdev = _mboard[MBOARD_PROP_RX_DBOARD][DBOARD_PROP_SUBDEV];
+        _tx_subdev = _mboard[MBOARD_PROP_TX_DBOARD][DBOARD_PROP_SUBDEV];
+    }
+
+    ~simple_device_impl(void){
+        /* NOP */
+    }
+
+    device::sptr get_device(void){
+        return _dev;
+    }
+
+    std::string get_name(void){
+        return _mboard[MBOARD_PROP_NAME].as<std::string>();
+    }
+
+    /*******************************************************************
+     * Streaming
+     ******************************************************************/
+    void set_streaming(bool enb){
+        _rx_ddc[std::string("enabled")] = enb;
+    }
+
+    bool get_streaming(void){
+        return _rx_ddc[std::string("enabled")].as<bool>();
+    }
+
+    /*******************************************************************
+     * RX methods
+     ******************************************************************/
+    void set_rx_rate(double rate){
+        double samp_rate = _rx_ddc[std::string("rate")].as<double>();
+        assert_has(get_rx_rates(), rate, "simple device rx rate");
+        _rx_ddc[std::string("decim")] = size_t(samp_rate/rate);
+    }
+
+    double get_rx_rate(void){
+        double samp_rate = _rx_ddc[std::string("rate")].as<double>();
+        size_t decim = _rx_ddc[std::string("decim")].as<size_t>();
+        return samp_rate/decim;
+    }
+
+    std::vector<double> get_rx_rates(void){
+        return get_xx_rates(_rx_ddc[std::string("decims")], _rx_ddc[std::string("rate")]);
+    }
+
+    tune_result_t set_rx_freq(double target_freq){
+        double lo_offset = 0.0;
+        //if the local oscillator will be in the passband, use an offset
+        if (_rx_subdev[SUBDEV_PROP_LO_INTERFERES].as<bool>()){
+            lo_offset = get_rx_rate()*2.0;
+        }
+        return tune(target_freq, lo_offset, _rx_subdev, _rx_ddc, false/* not tx */);
+    }
+
+    std::vector<double> get_rx_freq_range(void){
+        std::vector<double> range(2);
+        boost::tie(range[0], range[1]) = \
+            _rx_subdev[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>();
+        return range;
+    }
+
+    void set_rx_gain(float gain){
+        _rx_subdev[SUBDEV_PROP_GAIN] = gain;
+    }
+
+    float get_rx_gain(void){
+        return _rx_subdev[SUBDEV_PROP_GAIN].as<gain_t>();
+    }
+
+    std::vector<float> get_rx_gain_range(void){
+        std::vector<float> range(3);
+        boost::tie(range[0], range[1], range[2]) = \
+            _rx_subdev[SUBDEV_PROP_GAIN_RANGE].as<gain_range_t>();
+        return range;
+    }
+
+    void set_rx_antenna(const std::string &ant){
+        _rx_subdev[SUBDEV_PROP_ANTENNA] = ant;
+    }
+
+    std::string get_rx_antenna(void){
+        return _rx_subdev[SUBDEV_PROP_ANTENNA].as<std::string>();
+    }
+
+    std::vector<std::string> get_rx_antennas(void){
+        return _rx_subdev[SUBDEV_PROP_ANTENNA_NAMES].as<std::vector<std::string> >();
+    }
+
+    /*******************************************************************
+     * TX methods
+     ******************************************************************/
+    void set_tx_rate(double rate){
+        double samp_rate = _tx_duc[std::string("rate")].as<double>();
+        assert_has(get_tx_rates(), rate, "simple device tx rate");
+        _tx_duc[std::string("interp")] = size_t(samp_rate/rate);
+    }
+
+    double get_tx_rate(void){
+        double samp_rate = _tx_duc[std::string("rate")].as<double>();
+        size_t interp = _tx_duc[std::string("interp")].as<size_t>();
+        return samp_rate/interp;
+    }
+
+    std::vector<double> get_tx_rates(void){
+        return get_xx_rates(_tx_duc[std::string("interps")], _tx_duc[std::string("rate")]);
+    }
+
+    tune_result_t set_tx_freq(double target_freq){
+        double lo_offset = 0.0;
+        //if the local oscillator will be in the passband, use an offset
+        if (_tx_subdev[SUBDEV_PROP_LO_INTERFERES].as<bool>()){
+            lo_offset = get_tx_rate()*2.0;
+        }
+        return tune(target_freq, lo_offset, _tx_subdev, _tx_duc, true/* is tx */);
+    }
+
+    std::vector<double> get_tx_freq_range(void){
+        std::vector<double> range(2);
+        boost::tie(range[0], range[1]) = \
+            _tx_subdev[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>();
+        return range;
+    }
+
+    void set_tx_gain(float gain){
+        _tx_subdev[SUBDEV_PROP_GAIN] = gain;
+    }
+
+    float get_tx_gain(void){
+        return _tx_subdev[SUBDEV_PROP_GAIN].as<gain_t>();
+    }
+
+    std::vector<float> get_tx_gain_range(void){
+        std::vector<float> range(3);
+        boost::tie(range[0], range[1], range[2]) = \
+            _tx_subdev[SUBDEV_PROP_GAIN_RANGE].as<gain_range_t>();
+        return range;
+    }
+
+    void set_tx_antenna(const std::string &ant){
+        _tx_subdev[SUBDEV_PROP_ANTENNA] = ant;
+    }
+
+    std::string get_tx_antenna(void){
+        return _tx_subdev[SUBDEV_PROP_ANTENNA].as<std::string>();
+    }
+
+    std::vector<std::string> get_tx_antennas(void){
+        return _tx_subdev[SUBDEV_PROP_ANTENNA_NAMES].as<std::vector<std::string> >();
+    }
+
+private:
+    device::sptr _dev;
+    wax::obj _mboard;
+    wax::obj _rx_ddc;
+    wax::obj _tx_duc;
+    wax::obj _rx_subdev;
+    wax::obj _tx_subdev;
+};
+
+/***********************************************************************
+ * The Make Function
+ **********************************************************************/
+simple_device::sptr simple_device::make(const std::string &args){
+    return sptr(new simple_device_impl(args_to_device_addr(args)));
+}
diff --git a/host/lib/usrp/dboard_id.cpp b/host/lib/time_spec.cpp
index d2ef7cd7d..193441342 100644
--- a/host/lib/usrp/dboard_id.cpp
+++ b/host/lib/time_spec.cpp
@@ -15,20 +15,26 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include <uhd/usrp/dboard_id.hpp>
-#include <boost/format.hpp>
-#include <uhd/dict.hpp>
+#include <uhd/time_spec.hpp>
 
-using namespace uhd::usrp;
+using namespace uhd;
 
-std::string dboard_id::to_string(const dboard_id_t &id){
-    //map the dboard ids to string representations
-    uhd::dict<dboard_id_t, std::string> id_to_str;
-    id_to_str[ID_NONE]     = "none";
-    id_to_str[ID_BASIC_TX] = "basic tx";
-    id_to_str[ID_BASIC_RX] = "basic rx";
+time_spec_t::time_spec_t(void){
+    secs = ~0;
+    ticks = ~0;
+}
+
+time_spec_t::time_spec_t(uint32_t new_secs, uint32_t new_ticks){
+    secs = new_secs;
+    ticks = new_ticks;
+}
+
+static const boost::posix_time::ptime epoch(boost::gregorian::date(1970,1,1));
+static double time_tick_rate(boost::posix_time::time_duration::ticks_per_second());
 
-    //get the string representation
-    std::string name = (id_to_str.has_key(id))? id_to_str[id] : "unknown";
-    return str(boost::format("%s (0x%.4x)") % name % id);
+time_spec_t::time_spec_t(boost::posix_time::ptime time, double tick_rate){
+    boost::posix_time::time_duration td = time - epoch;
+    secs = td.total_seconds();
+    double time_ticks_per_device_ticks = time_tick_rate/tick_rate;
+    ticks = td.fractional_seconds()/time_ticks_per_device_ticks;
 }
diff --git a/host/lib/transport/udp.cpp b/host/lib/transport/udp.cpp
deleted file mode 100644
index 878f71410..000000000
--- a/host/lib/transport/udp.cpp
+++ /dev/null
@@ -1,98 +0,0 @@
-//
-// Copyright 2010 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#include <uhd/transport/udp.hpp>
-#include <boost/format.hpp>
-#include <iostream>
-
-/***********************************************************************
- * UDP implementation class
- **********************************************************************/
-class udp_impl : public uhd::transport::udp{
-public:
-    //structors
-    udp_impl(const std::string &addr, const std::string &port, bool bcast);
-    ~udp_impl(void);
-
-    //send/recv
-    size_t send(const std::vector<boost::asio::const_buffer> &buffs);
-    size_t send(const boost::asio::const_buffer &buff);
-    size_t recv(const std::vector<boost::asio::mutable_buffer> &buffs);
-    size_t recv(const boost::asio::mutable_buffer &buff);
-
-private:
-    boost::asio::ip::udp::socket   *_socket;
-    boost::asio::ip::udp::endpoint _receiver_endpoint;
-    boost::asio::ip::udp::endpoint _sender_endpoint;
-    boost::asio::io_service        _io_service;
-};
-
-/***********************************************************************
- * UDP public make function
- **********************************************************************/
-uhd::transport::udp::sptr uhd::transport::udp::make(
-    const std::string &addr,
-    const std::string &port,
-    bool bcast
-){
-    return uhd::transport::udp::sptr(new udp_impl(addr, port, bcast));
-}
-
-/***********************************************************************
- * UDP implementation methods
- **********************************************************************/
-udp_impl::udp_impl(const std::string &addr, const std::string &port, bool bcast){
-    //std::cout << boost::format("Creating udp transport for %s %s") % addr % port << std::endl;
-
-    // resolve the address
-    boost::asio::ip::udp::resolver resolver(_io_service);
-    boost::asio::ip::udp::resolver::query query(boost::asio::ip::udp::v4(), addr, port);
-    _receiver_endpoint = *resolver.resolve(query);
-
-    // Create and open the socket
-    _socket = new boost::asio::ip::udp::socket(_io_service);
-    _socket->open(boost::asio::ip::udp::v4());
-
-    if (bcast){
-        // Allow broadcasting
-        boost::asio::socket_base::broadcast option(true);
-        _socket->set_option(option);
-    }
-
-}
-
-udp_impl::~udp_impl(void){
-    delete _socket;
-}
-
-size_t udp_impl::send(const std::vector<boost::asio::const_buffer> &buffs){
-    return _socket->send_to(buffs, _receiver_endpoint);
-}
-
-size_t udp_impl::send(const boost::asio::const_buffer &buff){
-    return _socket->send_to(boost::asio::buffer(buff), _receiver_endpoint);
-}
-
-size_t udp_impl::recv(const std::vector<boost::asio::mutable_buffer> &buffs){
-    if (_socket->available() == 0) return 0;
-    return _socket->receive_from(buffs, _sender_endpoint);
-}
-
-size_t udp_impl::recv(const boost::asio::mutable_buffer &buff){
-    if (_socket->available() == 0) return 0;
-    return _socket->receive_from(boost::asio::buffer(buff), _sender_endpoint);
-}
diff --git a/host/lib/transport/udp_simple.cpp b/host/lib/transport/udp_simple.cpp
new file mode 100644
index 000000000..7004bdfdf
--- /dev/null
+++ b/host/lib/transport/udp_simple.cpp
@@ -0,0 +1,158 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/transport/udp_simple.hpp>
+#include <boost/thread.hpp>
+#include <boost/format.hpp>
+#include <iostream>
+
+using namespace uhd::transport;
+
+/***********************************************************************
+ * Helper Functions
+ **********************************************************************/
+/*!
+ * A receive timeout for a socket:
+ *
+ * It seems that asio cannot have timeouts with synchronous io.
+ * However, we can implement a polling loop that will timeout.
+ * This is okay bacause this is the slow-path implementation.
+ *
+ * \param socket the asio socket
+ */
+static void reasonable_recv_timeout(
+    boost::asio::ip::udp::socket &socket
+){
+    boost::asio::deadline_timer timer(socket.get_io_service());
+    timer.expires_from_now(boost::posix_time::milliseconds(50));
+    while (not (socket.available() or timer.expires_from_now().is_negative())){
+        boost::this_thread::sleep(boost::posix_time::milliseconds(1));
+    }
+}
+
+/***********************************************************************
+ * UDP connected implementation class
+ **********************************************************************/
+class udp_connected_impl : public udp_simple{
+public:
+    //structors
+    udp_connected_impl(const std::string &addr, const std::string &port);
+    ~udp_connected_impl(void);
+
+    //send/recv
+    size_t send(const boost::asio::const_buffer &buff);
+    size_t recv(const boost::asio::mutable_buffer &buff);
+
+private:
+    boost::asio::ip::udp::socket   *_socket;
+    boost::asio::io_service        _io_service;
+};
+
+udp_connected_impl::udp_connected_impl(const std::string &addr, const std::string &port){
+    //std::cout << boost::format("Creating udp transport for %s %s") % addr % port << std::endl;
+
+    // resolve the address
+    boost::asio::ip::udp::resolver resolver(_io_service);
+    boost::asio::ip::udp::resolver::query query(boost::asio::ip::udp::v4(), addr, port);
+    boost::asio::ip::udp::endpoint receiver_endpoint = *resolver.resolve(query);
+
+    // Create, open, and connect the socket
+    _socket = new boost::asio::ip::udp::socket(_io_service);
+    _socket->open(boost::asio::ip::udp::v4());
+    _socket->connect(receiver_endpoint);
+}
+
+udp_connected_impl::~udp_connected_impl(void){
+    delete _socket;
+}
+
+size_t udp_connected_impl::send(const boost::asio::const_buffer &buff){
+    return _socket->send(boost::asio::buffer(buff));
+}
+
+size_t udp_connected_impl::recv(const boost::asio::mutable_buffer &buff){
+    reasonable_recv_timeout(*_socket);
+    if (not _socket->available()) return 0;
+    return _socket->receive(boost::asio::buffer(buff));
+}
+
+/***********************************************************************
+ * UDP broadcast implementation class
+ **********************************************************************/
+class udp_broadcast_impl : public udp_simple{
+public:
+    //structors
+    udp_broadcast_impl(const std::string &addr, const std::string &port);
+    ~udp_broadcast_impl(void);
+
+    //send/recv
+    size_t send(const boost::asio::const_buffer &buff);
+    size_t recv(const boost::asio::mutable_buffer &buff);
+
+private:
+    boost::asio::ip::udp::socket   *_socket;
+    boost::asio::ip::udp::endpoint _receiver_endpoint;
+    boost::asio::io_service        _io_service;
+};
+
+udp_broadcast_impl::udp_broadcast_impl(const std::string &addr, const std::string &port){
+    //std::cout << boost::format("Creating udp transport for %s %s") % addr % port << std::endl;
+
+    // resolve the address
+    boost::asio::ip::udp::resolver resolver(_io_service);
+    boost::asio::ip::udp::resolver::query query(boost::asio::ip::udp::v4(), addr, port);
+    _receiver_endpoint = *resolver.resolve(query);
+
+    // Create and open the socket
+    _socket = new boost::asio::ip::udp::socket(_io_service);
+    _socket->open(boost::asio::ip::udp::v4());
+
+    // Allow broadcasting
+    boost::asio::socket_base::broadcast option(true);
+    _socket->set_option(option);
+
+}
+
+udp_broadcast_impl::~udp_broadcast_impl(void){
+    delete _socket;
+}
+
+size_t udp_broadcast_impl::send(const boost::asio::const_buffer &buff){
+    return _socket->send_to(boost::asio::buffer(buff), _receiver_endpoint);
+}
+
+size_t udp_broadcast_impl::recv(const boost::asio::mutable_buffer &buff){
+    reasonable_recv_timeout(*_socket);
+    if (not _socket->available()) return 0;
+    boost::asio::ip::udp::endpoint sender_endpoint;
+    return _socket->receive_from(boost::asio::buffer(buff), sender_endpoint);
+}
+
+/***********************************************************************
+ * UDP public make functions
+ **********************************************************************/
+udp_simple::sptr udp_simple::make_connected(
+    const std::string &addr, const std::string &port
+){
+    return sptr(new udp_connected_impl(addr, port));
+}
+
+udp_simple::sptr udp_simple::make_broadcast(
+    const std::string &addr, const std::string &port
+){
+    return sptr(new udp_broadcast_impl(addr, port));
+}
diff --git a/host/lib/transport/udp_zero_copy_none.cpp b/host/lib/transport/udp_zero_copy_none.cpp
new file mode 100644
index 000000000..e29530cf1
--- /dev/null
+++ b/host/lib/transport/udp_zero_copy_none.cpp
@@ -0,0 +1,152 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/transport/udp_zero_copy.hpp>
+#include <boost/thread.hpp>
+#include <boost/format.hpp>
+
+using namespace uhd::transport;
+
+/***********************************************************************
+ * Smart buffer implementation for udp zerocopy none
+ *
+ * This smart buffer implemention houses a const buffer.
+ * When the smart buffer is deleted, the buffer is freed.
+ * The memory in the const buffer is allocated with new [],
+ * and so the destructor frees the buffer with delete [].
+ **********************************************************************/
+class smart_buffer_impl : public smart_buffer{
+public:
+    smart_buffer_impl(const boost::asio::const_buffer &buff){
+        _buff = buff;
+    }
+
+    ~smart_buffer_impl(void){
+        delete [] boost::asio::buffer_cast<const uint32_t *>(_buff);
+    }
+
+    const boost::asio::const_buffer &get(void) const{
+        return _buff;
+    }
+
+private:
+    boost::asio::const_buffer _buff;
+};
+
+/***********************************************************************
+ * UDP zero copy implementation class
+ *
+ * This is the portable zero copy implementation for systems
+ * where a faster, platform specific solution is not available.
+ *
+ * It uses boost asio udp sockets and the standard recv() class,
+ * and in-fact, is not actually doing a zero-copy implementation.
+ **********************************************************************/
+class udp_zero_copy_impl : public udp_zero_copy{
+public:
+    //structors
+    udp_zero_copy_impl(const std::string &addr, const std::string &port);
+    ~udp_zero_copy_impl(void);
+
+    //send/recv
+    size_t send(const boost::asio::const_buffer &buff);
+    smart_buffer::sptr recv(void);
+
+private:
+    boost::asio::ip::udp::socket   *_socket;
+    boost::asio::io_service        _io_service;
+
+    size_t get_recv_buff_size(void);
+    void set_recv_buff_size(size_t);
+};
+
+udp_zero_copy_impl::udp_zero_copy_impl(const std::string &addr, const std::string &port){
+    //std::cout << boost::format("Creating udp transport for %s %s") % addr % port << std::endl;
+
+    // resolve the address
+    boost::asio::ip::udp::resolver resolver(_io_service);
+    boost::asio::ip::udp::resolver::query query(boost::asio::ip::udp::v4(), addr, port);
+    boost::asio::ip::udp::endpoint receiver_endpoint = *resolver.resolve(query);
+
+    // Create, open, and connect the socket
+    _socket = new boost::asio::ip::udp::socket(_io_service);
+    _socket->open(boost::asio::ip::udp::v4());
+    _socket->connect(receiver_endpoint);
+
+    // set the rx socket buffer size:
+    // pick a huge size, and deal with whatever we get
+    set_recv_buff_size(54321e3); //some big number!
+    size_t current_buff_size = get_recv_buff_size();
+    std::cout << boost::format(
+        "Current rx socket buffer size: %d\n"
+    ) % current_buff_size;
+    if (current_buff_size < .1e6) std::cout << boost::format(
+        "Adjust max rx socket buffer size (linux only):\n"
+        "  sysctl -w net.core.rmem_max=VALUE\n"
+    );
+}
+
+udp_zero_copy_impl::~udp_zero_copy_impl(void){
+    delete _socket;
+}
+
+size_t udp_zero_copy_impl::send(const boost::asio::const_buffer &buff){
+    return _socket->send(boost::asio::buffer(buff));
+}
+
+smart_buffer::sptr udp_zero_copy_impl::recv(void){
+    size_t available = 0;
+
+    //implement timeout through polling and sleeping
+    boost::asio::deadline_timer timer(_socket->get_io_service());
+    timer.expires_from_now(boost::posix_time::milliseconds(50));
+    while (not ((available = _socket->available()) or timer.expires_from_now().is_negative())){
+        boost::this_thread::sleep(boost::posix_time::milliseconds(1));
+    }
+
+    //allocate memory and create buffer
+    uint32_t *buff_mem = new uint32_t[available/sizeof(uint32_t)];
+    boost::asio::mutable_buffer buff(buff_mem, available);
+
+    //receive only if data is available
+    if (available){
+        _socket->receive(boost::asio::buffer(buff));
+    }
+
+    //create a new smart buffer to house the data
+    return smart_buffer::sptr(new smart_buffer_impl(buff));
+}
+
+size_t udp_zero_copy_impl::get_recv_buff_size(void){
+    boost::asio::socket_base::receive_buffer_size option;
+    _socket->get_option(option);
+    return option.value();
+}
+
+void udp_zero_copy_impl::set_recv_buff_size(size_t new_size){
+    boost::asio::socket_base::receive_buffer_size option(new_size);
+    _socket->set_option(option);
+}
+
+/***********************************************************************
+ * UDP zero copy make function
+ **********************************************************************/
+udp_zero_copy::sptr udp_zero_copy::make(
+    const std::string &addr, const std::string &port
+){
+    return sptr(new udp_zero_copy_impl(addr, port));
+}
diff --git a/host/lib/transport/vrt.cpp b/host/lib/transport/vrt.cpp
new file mode 100644
index 000000000..5029df217
--- /dev/null
+++ b/host/lib/transport/vrt.cpp
@@ -0,0 +1,108 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/transport/vrt.hpp>
+#include <netinet/in.h>
+#include <stdexcept>
+
+using namespace uhd::transport;
+
+void vrt::pack(
+    const tx_metadata_t &metadata, //input
+    uint32_t *header_buff,         //output
+    size_t &num_header_words32,    //output
+    size_t num_payload_words32,    //input
+    size_t &num_packet_words32,    //output
+    size_t packet_count            //input
+){
+    uint32_t vrt_hdr_flags = 0;
+    num_header_words32 = 1;
+
+    //load the vrt header and flags
+    if(metadata.has_stream_id){
+        vrt_hdr_flags |= (0x1 << 28); //IF Data packet with Stream Identifier
+        header_buff[num_header_words32++] = htonl(metadata.stream_id);
+    }
+
+    if(metadata.has_time_spec){
+        vrt_hdr_flags |= (0x3 << 22) | (0x1 << 20); //TSI: Other, TSF: Sample Count Timestamp
+        header_buff[num_header_words32++] = htonl(metadata.time_spec.secs);
+        header_buff[num_header_words32++] = htonl(metadata.time_spec.ticks);
+        header_buff[num_header_words32++] = 0; //unused part of fractional seconds
+    }
+
+    vrt_hdr_flags |= (metadata.start_of_burst)? (0x1 << 25) : 0;
+    vrt_hdr_flags |= (metadata.end_of_burst)?   (0x1 << 24) : 0;
+
+    num_packet_words32 = num_header_words32 + num_payload_words32;
+
+    //fill in complete header word
+    header_buff[0] = htonl(vrt_hdr_flags |
+        ((packet_count & 0xf) << 16) |
+        (num_packet_words32 & 0xffff)
+    );
+}
+
+void vrt::unpack(
+    rx_metadata_t &metadata,         //output
+    const uint32_t *header_buff,     //input
+    size_t &num_header_words32,      //output
+    size_t &num_payload_words32,     //output
+    size_t num_packet_words32,       //input
+    size_t &packet_count             //output
+){
+    //clear the metadata
+    metadata = rx_metadata_t();
+
+    //extract vrt header
+    uint32_t vrt_hdr_word = ntohl(header_buff[0]);
+    size_t packet_words32 = vrt_hdr_word & 0xffff;
+    packet_count = (vrt_hdr_word >> 16) & 0xf;
+
+    //failure cases
+    if (packet_words32 == 0 or num_packet_words32 < packet_words32)
+        throw std::runtime_error("bad vrt header or packet fragment");
+    if (vrt_hdr_word & (0x7 << 29))
+        throw std::runtime_error("unsupported vrt packet type");
+
+    //parse the header flags
+    num_header_words32 = 1;
+
+    if (vrt_hdr_word & (0x1 << 28)){ //stream id
+        metadata.has_stream_id = true;
+        metadata.stream_id = ntohl(header_buff[num_header_words32++]);
+    }
+
+    if (vrt_hdr_word & (0x1 << 27)){ //class id (we dont use)
+        num_header_words32 += 2;
+    }
+
+    if (vrt_hdr_word & (0x3 << 22)){ //integer time
+        metadata.has_time_spec = true;
+        metadata.time_spec.secs = ntohl(header_buff[num_header_words32++]);
+    }
+
+    if (vrt_hdr_word & (0x3 << 20)){ //fractional time
+        metadata.has_time_spec = true;
+        metadata.time_spec.ticks = ntohl(header_buff[num_header_words32++]);
+        num_header_words32++; //unused part of fractional seconds
+    }
+
+    size_t num_trailer_words32 = (vrt_hdr_word & (0x1 << 26))? 1 : 0;
+
+    num_payload_words32 = packet_words32 - num_header_words32 - num_trailer_words32;
+}
diff --git a/host/lib/uhd.cpp b/host/lib/uhd.cpp
deleted file mode 100644
index 5e250c76f..000000000
--- a/host/lib/uhd.cpp
+++ /dev/null
@@ -1,20 +0,0 @@
-//
-// Copyright 2010 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#include <uhd.hpp>
-
-//nothing here, just includes the header so the compiler can check
diff --git a/host/lib/usrp/dboard/basic.cpp b/host/lib/usrp/dboard/basic.cpp
index f39ebff2f..095b77ce1 100644
--- a/host/lib/usrp/dboard/basic.cpp
+++ b/host/lib/usrp/dboard/basic.cpp
@@ -15,42 +15,282 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include "dboards.hpp"
+#include <uhd/utils.hpp>
+#include <uhd/props.hpp>
+#include <uhd/usrp/dboard_base.hpp>
+#include <uhd/usrp/dboard_manager.hpp>
+#include <boost/assign/list_of.hpp>
+#include <boost/format.hpp>
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace boost::assign;
 
 /***********************************************************************
- * Basic RX dboard
+ * The basic and lf boards:
+ *   They share a common class because only the frequency bounds differ.
  **********************************************************************/
-basic_rx::basic_rx(ctor_args_t const& args) : rx_dboard_base(args){
-    /* NOP */
+class basic_rx : public rx_dboard_base{
+public:
+    basic_rx(ctor_args_t const& args, freq_t max_freq);
+    ~basic_rx(void);
+
+    void rx_get(const wax::obj &key, wax::obj &val);
+    void rx_set(const wax::obj &key, const wax::obj &val);
+
+private:
+    freq_t _max_freq;
+};
+
+class basic_tx : public tx_dboard_base{
+public:
+    basic_tx(ctor_args_t const& args, freq_t max_freq);
+    ~basic_tx(void);
+
+    void tx_get(const wax::obj &key, wax::obj &val);
+    void tx_set(const wax::obj &key, const wax::obj &val);
+
+private:
+    freq_t _max_freq;
+};
+
+/***********************************************************************
+ * Register the basic and LF dboards
+ **********************************************************************/
+static dboard_base::sptr make_basic_rx(dboard_base::ctor_args_t const& args){
+    return dboard_base::sptr(new basic_rx(args, 90e9));
+}
+
+static dboard_base::sptr make_basic_tx(dboard_base::ctor_args_t const& args){
+    return dboard_base::sptr(new basic_tx(args, 90e9));
+}
+
+static dboard_base::sptr make_lf_rx(dboard_base::ctor_args_t const& args){
+    return dboard_base::sptr(new basic_rx(args, 32e6));
+}
+
+static dboard_base::sptr make_lf_tx(dboard_base::ctor_args_t const& args){
+    return dboard_base::sptr(new basic_tx(args, 32e6));
+}
+
+STATIC_BLOCK(reg_dboards){
+    dboard_manager::register_dboard(0x0000, &make_basic_tx, "Basic TX", list_of(""));
+    dboard_manager::register_dboard(0x0001, &make_basic_rx, "Basic RX", list_of("a")("b")("ab"));
+    dboard_manager::register_dboard(0x000e, &make_lf_tx,    "LF TX",    list_of(""));
+    dboard_manager::register_dboard(0x000f, &make_lf_rx,    "LF RX",    list_of("a")("b")("ab"));
+}
+
+/***********************************************************************
+ * Basic and LF RX dboard
+ **********************************************************************/
+basic_rx::basic_rx(ctor_args_t const& args, freq_t max_freq) : rx_dboard_base(args){
+    _max_freq = max_freq;
+    // set the gpios to safe values (all inputs)
+    get_interface()->set_gpio_ddr(dboard_interface::GPIO_RX_BANK, 0x0000, 0xffff);
 }
 
 basic_rx::~basic_rx(void){
     /* NOP */
 }
 
-void basic_rx::rx_get(const wax::obj &, wax::obj &){
-    /* TODO */
+void basic_rx::rx_get(const wax::obj &key_, wax::obj &val){
+    wax::obj key; std::string name;
+    boost::tie(key, name) = extract_named_prop(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<subdev_prop_t>()){
+    case SUBDEV_PROP_NAME:
+        val = std::string(str(boost::format("%s:%s")
+            % dboard_id::to_string(get_rx_id())
+            % get_subdev_name()
+        ));
+        return;
+
+    case SUBDEV_PROP_OTHERS:
+        val = prop_names_t(); //empty
+        return;
+
+    case SUBDEV_PROP_GAIN:
+        val = gain_t(0);
+        return;
+
+    case SUBDEV_PROP_GAIN_RANGE:
+        val = gain_range_t(0, 0, 0);
+        return;
+
+    case SUBDEV_PROP_GAIN_NAMES:
+        val = prop_names_t(); //empty
+        return;
+
+    case SUBDEV_PROP_FREQ:
+        val = freq_t(0);
+        return;
+
+    case SUBDEV_PROP_FREQ_RANGE:
+        val = freq_range_t(+_max_freq, -_max_freq);
+        return;
+
+    case SUBDEV_PROP_ANTENNA:
+        val = std::string("");
+        return;
+
+    case SUBDEV_PROP_ANTENNA_NAMES:
+        val = prop_names_t(1, ""); //vector of 1 empty string
+        return;
+
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
+    case SUBDEV_PROP_QUADRATURE:
+        val = (get_subdev_name() == "ab"); //only quadrature in ab mode
+        return;
+
+    case SUBDEV_PROP_IQ_SWAPPED:
+    case SUBDEV_PROP_SPECTRUM_INVERTED:
+    case SUBDEV_PROP_LO_INTERFERES:
+        val = false;
+        return;
+    }
 }
 
-void basic_rx::rx_set(const wax::obj &, const wax::obj &){
-    /* TODO */
+void basic_rx::rx_set(const wax::obj &key_, const wax::obj &val){
+    wax::obj key; std::string name;
+    boost::tie(key, name) = extract_named_prop(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<subdev_prop_t>()){
+
+    case SUBDEV_PROP_GAIN:
+        ASSERT_THROW(val.as<gain_t>() == gain_t(0));
+        return;
+
+    case SUBDEV_PROP_ANTENNA:
+        ASSERT_THROW(val.as<std::string>() == std::string(""));
+        return;
+
+    case SUBDEV_PROP_ENABLED:
+        return; // it wont do you much good, but you can set it
+
+    case SUBDEV_PROP_NAME:
+    case SUBDEV_PROP_OTHERS:
+    case SUBDEV_PROP_GAIN_RANGE:
+    case SUBDEV_PROP_GAIN_NAMES:
+    case SUBDEV_PROP_FREQ:
+    case SUBDEV_PROP_FREQ_RANGE:
+    case SUBDEV_PROP_ANTENNA_NAMES:
+    case SUBDEV_PROP_QUADRATURE:
+    case SUBDEV_PROP_IQ_SWAPPED:
+    case SUBDEV_PROP_SPECTRUM_INVERTED:
+    case SUBDEV_PROP_LO_INTERFERES:
+        throw std::runtime_error(str(boost::format(
+            "Error: trying to set read-only property on %s subdev"
+        ) % dboard_id::to_string(get_rx_id())));
+    }
 }
 
 /***********************************************************************
- * Basic TX dboard
+ * Basic and LF TX dboard
  **********************************************************************/
-basic_tx::basic_tx(ctor_args_t const& args) : tx_dboard_base(args){
-    /* NOP */
+basic_tx::basic_tx(ctor_args_t const& args, freq_t max_freq) : tx_dboard_base(args){
+    _max_freq = max_freq;
+    // set the gpios to safe values (all inputs)
+    get_interface()->set_gpio_ddr(dboard_interface::GPIO_TX_BANK, 0x0000, 0xffff);
 }
 
 basic_tx::~basic_tx(void){
     /* NOP */
 }
 
-void basic_tx::tx_get(const wax::obj &, wax::obj &){
-    /* TODO */
+void basic_tx::tx_get(const wax::obj &key_, wax::obj &val){
+    wax::obj key; std::string name;
+    boost::tie(key, name) = extract_named_prop(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<subdev_prop_t>()){
+    case SUBDEV_PROP_NAME:
+        val = dboard_id::to_string(get_tx_id());
+        return;
+
+    case SUBDEV_PROP_OTHERS:
+        val = prop_names_t(); //empty
+        return;
+
+    case SUBDEV_PROP_GAIN:
+        val = gain_t(0);
+        return;
+
+    case SUBDEV_PROP_GAIN_RANGE:
+        val = gain_range_t(0, 0, 0);
+        return;
+
+    case SUBDEV_PROP_GAIN_NAMES:
+        val = prop_names_t(); //empty
+        return;
+
+    case SUBDEV_PROP_FREQ:
+        val = freq_t(0);
+        return;
+
+    case SUBDEV_PROP_FREQ_RANGE:
+        val = freq_range_t(+_max_freq, -_max_freq);
+        return;
+
+    case SUBDEV_PROP_ANTENNA:
+        val = std::string("");
+        return;
+
+    case SUBDEV_PROP_ANTENNA_NAMES:
+        val = prop_names_t(1, ""); //vector of 1 empty string
+        return;
+
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
+    case SUBDEV_PROP_QUADRATURE:
+        val = true;
+        return;
+
+    case SUBDEV_PROP_IQ_SWAPPED:
+    case SUBDEV_PROP_SPECTRUM_INVERTED:
+    case SUBDEV_PROP_LO_INTERFERES:
+        val = false;
+        return;
+    }
 }
 
-void basic_tx::tx_set(const wax::obj &, const wax::obj &){
-    /* TODO */
+void basic_tx::tx_set(const wax::obj &key_, const wax::obj &val){
+    wax::obj key; std::string name;
+    boost::tie(key, name) = extract_named_prop(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<subdev_prop_t>()){
+
+    case SUBDEV_PROP_GAIN:
+        ASSERT_THROW(val.as<gain_t>() == gain_t(0));
+        return;
+
+    case SUBDEV_PROP_ANTENNA:
+        ASSERT_THROW(val.as<std::string>() == std::string(""));
+        return;
+
+    case SUBDEV_PROP_ENABLED:
+        return; // it wont do you much good, but you can set it
+
+    case SUBDEV_PROP_NAME:
+    case SUBDEV_PROP_OTHERS:
+    case SUBDEV_PROP_GAIN_RANGE:
+    case SUBDEV_PROP_GAIN_NAMES:
+    case SUBDEV_PROP_FREQ:
+    case SUBDEV_PROP_FREQ_RANGE:
+    case SUBDEV_PROP_ANTENNA_NAMES:
+    case SUBDEV_PROP_QUADRATURE:
+    case SUBDEV_PROP_IQ_SWAPPED:
+    case SUBDEV_PROP_SPECTRUM_INVERTED:
+    case SUBDEV_PROP_LO_INTERFERES:
+        throw std::runtime_error(str(boost::format(
+            "Error: trying to set read-only property on %s subdev"
+        ) % dboard_id::to_string(get_tx_id())));
+    }
 }
diff --git a/host/lib/usrp/dboard/dboards.hpp b/host/lib/usrp/dboard/dboards.hpp
deleted file mode 100644
index 79b90d593..000000000
--- a/host/lib/usrp/dboard/dboards.hpp
+++ /dev/null
@@ -1,53 +0,0 @@
-//
-// Copyright 2010 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#ifndef INCLUDED_LOCAL_DBOARDS_HPP
-#define INCLUDED_LOCAL_DBOARDS_HPP
-
-#include <uhd/usrp/dboard_base.hpp>
-
-using namespace uhd::usrp;
-
-/***********************************************************************
- * The basic boards:
- **********************************************************************/
-class basic_rx : public rx_dboard_base{
-public:
-    static dboard_base::sptr make(ctor_args_t const& args){
-        return dboard_base::sptr(new basic_rx(args));
-    }
-    basic_rx(ctor_args_t const& args);
-    ~basic_rx(void);
-
-    void rx_get(const wax::obj &key, wax::obj &val);
-    void rx_set(const wax::obj &key, const wax::obj &val);
-};
-
-class basic_tx : public tx_dboard_base{
-public:
-    static dboard_base::sptr make(ctor_args_t const& args){
-        return dboard_base::sptr(new basic_tx(args));
-    }
-    basic_tx(ctor_args_t const& args);
-    ~basic_tx(void);
-
-    void tx_get(const wax::obj &key, wax::obj &val);
-    void tx_set(const wax::obj &key, const wax::obj &val);
-
-};
-
-#endif /* INCLUDED_LOCAL_DBOARDS_HPP */
diff --git a/host/lib/usrp/dboard_manager.cpp b/host/lib/usrp/dboard_manager.cpp
index cce239f3e..eeabbda99 100644
--- a/host/lib/usrp/dboard_manager.cpp
+++ b/host/lib/usrp/dboard_manager.cpp
@@ -16,87 +16,49 @@
 //
 
 #include <uhd/usrp/dboard_manager.hpp>
+#include <uhd/gain_handler.hpp>
 #include <uhd/utils.hpp>
 #include <uhd/dict.hpp>
-#include <boost/assign/list_of.hpp>
 #include <boost/tuple/tuple.hpp>
 #include <boost/format.hpp>
+#include <boost/bind.hpp>
 #include <boost/foreach.hpp>
-#include "dboard/dboards.hpp"
 
 using namespace uhd;
 using namespace uhd::usrp;
-using namespace boost::assign;
-
-/***********************************************************************
- * register internal dboards
- *
- * Register internal/known dboards located in this build tree.
- * Each board should have entries below mapping an id to a constructor.
- * The xcvr type boards should register both rx and tx sides.
- *
- * This function will be called before new boards are registered.
- * This allows for internal boards to be externally overridden.
- * This function will also be called when creating a new dboard_manager
- * to ensure that the maps are filled with the entries below.
- **********************************************************************/
-static void register_internal_dboards(void){
-    //ensure that this function can only be called once per instance
-    static bool called = false;
-    if (called) return; called = true;
-    //register the known dboards (dboard id, constructor, subdev names)
-    dboard_manager::register_subdevs(ID_BASIC_TX, &basic_tx::make, list_of(""));
-    dboard_manager::register_subdevs(ID_BASIC_RX, &basic_rx::make, list_of("a")("b")("ab"));
-}
 
 /***********************************************************************
  * storage and registering for dboards
  **********************************************************************/
-typedef boost::tuple<dboard_manager::dboard_ctor_t, prop_names_t> args_t;
+//dboard registry tuple: dboard constructor, canonical name, subdev names
+typedef boost::tuple<dboard_manager::dboard_ctor_t, std::string, prop_names_t> args_t;
 
 //map a dboard id to a dboard constructor
-static uhd::dict<dboard_id_t, args_t> id_to_args_map;
+typedef uhd::dict<dboard_id_t, args_t> id_to_args_map_t;
+STATIC_INSTANCE(id_to_args_map_t, get_id_to_args_map)
 
-void dboard_manager::register_subdevs(
+void dboard_manager::register_dboard(
     dboard_id_t dboard_id,
     dboard_ctor_t dboard_ctor,
+    const std::string &name,
     const prop_names_t &subdev_names
 ){
-    register_internal_dboards(); //always call first
-    id_to_args_map[dboard_id] = args_t(dboard_ctor, subdev_names);
+    //std::cout << "registering: " << name << std::endl;
+    if (get_id_to_args_map().has_key(dboard_id)){
+        throw std::runtime_error(str(boost::format(
+            "The dboard id 0x%.4x is already registered to %s."
+        ) % dboard_id % dboard_id::to_string(dboard_id)));
+    }
+    get_id_to_args_map()[dboard_id] = args_t(dboard_ctor, name, subdev_names);
 }
 
-/***********************************************************************
- * dboard manager implementation class
- **********************************************************************/
-class dboard_manager_impl : public dboard_manager{
-
-public:
-    dboard_manager_impl(
-        dboard_id_t rx_dboard_id,
-        dboard_id_t tx_dboard_id,
-        dboard_interface::sptr interface
-    );
-    ~dboard_manager_impl(void);
-
-    //dboard_interface
-    prop_names_t get_rx_subdev_names(void);
-    prop_names_t get_tx_subdev_names(void);
-    wax::obj get_rx_subdev(const std::string &subdev_name);
-    wax::obj get_tx_subdev(const std::string &subdev_name);
-
-private:
-    //list of rx and tx dboards in this dboard_manager
-    //each dboard here is actually a subdevice proxy
-    //the subdevice proxy is internal to the cpp file
-    uhd::dict<std::string, wax::obj> _rx_dboards;
-    uhd::dict<std::string, wax::obj> _tx_dboards;
-    dboard_interface::sptr _interface;
-    void set_nice_gpio_pins(void);
-};
+std::string dboard_id::to_string(const dboard_id_t &id){
+    std::string name = (get_id_to_args_map().has_key(id))? get_id_to_args_map()[id].get<1>() : "unknown";
+    return str(boost::format("%s (0x%.4x)") % name % id);
+}
 
 /***********************************************************************
- * internal helper classes
+ * internal helper classe
  **********************************************************************/
 /*!
  * A special wax proxy object that forwards calls to a subdev.
@@ -110,7 +72,17 @@ public:
     //structors
     subdev_proxy(dboard_base::sptr subdev, type_t type)
     : _subdev(subdev), _type(type){
-        /* NOP */
+        //initialize gain props struct
+        gain_handler::props_t gain_props;
+        gain_props.value = SUBDEV_PROP_GAIN;
+        gain_props.range = SUBDEV_PROP_GAIN_RANGE;
+        gain_props.names = SUBDEV_PROP_GAIN_NAMES;
+
+        //make a new gain handler
+        _gain_handler = gain_handler::make(
+            this->get_link(), gain_props,
+            boost::bind(&gain_handler::is_equal<subdev_prop_t>, _1, _2)
+        );
     }
 
     ~subdev_proxy(void){
@@ -118,11 +90,13 @@ public:
     }
 
 private:
+    gain_handler::sptr   _gain_handler;
     dboard_base::sptr   _subdev;
     type_t              _type;
 
     //forward the get calls to the rx or tx
     void get(const wax::obj &key, wax::obj &val){
+        if (_gain_handler->intercept_get(key, val)) return;
         switch(_type){
         case RX_TYPE: return _subdev->rx_get(key, val);
         case TX_TYPE: return _subdev->tx_get(key, val);
@@ -131,6 +105,7 @@ private:
 
     //forward the set calls to the rx or tx
     void set(const wax::obj &key, const wax::obj &val){
+        if (_gain_handler->intercept_set(key, val)) return;
         switch(_type){
         case RX_TYPE: return _subdev->rx_set(key, val);
         case TX_TYPE: return _subdev->tx_set(key, val);
@@ -139,6 +114,35 @@ private:
 };
 
 /***********************************************************************
+ * dboard manager implementation class
+ **********************************************************************/
+class dboard_manager_impl : public dboard_manager{
+
+public:
+    dboard_manager_impl(
+        dboard_id_t rx_dboard_id,
+        dboard_id_t tx_dboard_id,
+        dboard_interface::sptr interface
+    );
+    ~dboard_manager_impl(void);
+
+    //dboard_interface
+    prop_names_t get_rx_subdev_names(void);
+    prop_names_t get_tx_subdev_names(void);
+    wax::obj get_rx_subdev(const std::string &subdev_name);
+    wax::obj get_tx_subdev(const std::string &subdev_name);
+
+private:
+    //list of rx and tx dboards in this dboard_manager
+    //each dboard here is actually a subdevice proxy
+    //the subdevice proxy is internal to the cpp file
+    uhd::dict<std::string, subdev_proxy::sptr> _rx_dboards;
+    uhd::dict<std::string, subdev_proxy::sptr> _tx_dboards;
+    dboard_interface::sptr _interface;
+    void set_nice_gpio_pins(void);
+};
+
+/***********************************************************************
  * make routine for dboard manager
  **********************************************************************/
 dboard_manager::sptr dboard_manager::make(
@@ -160,16 +164,16 @@ static args_t get_dboard_args(
 ){
     //special case, its rx and the none id (0xffff)
     if (xx_type == "rx" and dboard_id == ID_NONE){
-        return args_t(&basic_rx::make, list_of("ab"));
+        return get_dboard_args(0x0001, xx_type);
     }
 
     //special case, its tx and the none id (0xffff)
     if (xx_type == "tx" and dboard_id == ID_NONE){
-        return args_t(&basic_tx::make, list_of(""));
+        return get_dboard_args(0x0000, xx_type);
     }
 
     //verify that there is a registered constructor for this id
-    if (not id_to_args_map.has_key(dboard_id)){
+    if (not get_id_to_args_map().has_key(dboard_id)){
         throw std::runtime_error(str(
             boost::format("Unregistered %s dboard id: %s")
             % xx_type % dboard_id::to_string(dboard_id)
@@ -177,7 +181,7 @@ static args_t get_dboard_args(
     }
 
     //return the dboard args for this id
-    return id_to_args_map[dboard_id];
+    return get_id_to_args_map()[dboard_id];
 }
 
 dboard_manager_impl::dboard_manager_impl(
@@ -185,14 +189,13 @@ dboard_manager_impl::dboard_manager_impl(
     dboard_id_t tx_dboard_id,
     dboard_interface::sptr interface
 ){
-    register_internal_dboards(); //always call first
     _interface = interface;
 
-    dboard_ctor_t rx_dboard_ctor; prop_names_t rx_subdevs;
-    boost::tie(rx_dboard_ctor, rx_subdevs) = get_dboard_args(rx_dboard_id, "rx");
+    dboard_ctor_t rx_dboard_ctor; std::string rx_name; prop_names_t rx_subdevs;
+    boost::tie(rx_dboard_ctor, rx_name, rx_subdevs) = get_dboard_args(rx_dboard_id, "rx");
 
-    dboard_ctor_t tx_dboard_ctor; prop_names_t tx_subdevs;
-    boost::tie(tx_dboard_ctor, tx_subdevs) = get_dboard_args(tx_dboard_id, "tx");
+    dboard_ctor_t tx_dboard_ctor; std::string tx_name; prop_names_t tx_subdevs;
+    boost::tie(tx_dboard_ctor, tx_name, tx_subdevs) = get_dboard_args(tx_dboard_id, "tx");
 
     //initialize the gpio pins before creating subdevs
     set_nice_gpio_pins();
@@ -200,16 +203,16 @@ dboard_manager_impl::dboard_manager_impl(
     //make xcvr subdevs (make one subdev for both rx and tx dboards)
     if (rx_dboard_ctor == tx_dboard_ctor){
         ASSERT_THROW(rx_subdevs == tx_subdevs);
-        BOOST_FOREACH(std::string name, rx_subdevs){
+        BOOST_FOREACH(std::string subdev, rx_subdevs){
             dboard_base::sptr xcvr_dboard = rx_dboard_ctor(
-                dboard_base::ctor_args_t(name, interface, rx_dboard_id, tx_dboard_id)
+                dboard_base::ctor_args_t(subdev, interface, rx_dboard_id, tx_dboard_id)
             );
             //create a rx proxy for this xcvr board
-            _rx_dboards[name] = subdev_proxy::sptr(
+            _rx_dboards[subdev] = subdev_proxy::sptr(
                 new subdev_proxy(xcvr_dboard, subdev_proxy::RX_TYPE)
             );
             //create a tx proxy for this xcvr board
-            _tx_dboards[name] = subdev_proxy::sptr(
+            _tx_dboards[subdev] = subdev_proxy::sptr(
                 new subdev_proxy(xcvr_dboard, subdev_proxy::TX_TYPE)
             );
         }
@@ -218,22 +221,22 @@ dboard_manager_impl::dboard_manager_impl(
     //make tx and rx subdevs (separate subdevs for rx and tx dboards)
     else{
         //make the rx subdevs
-        BOOST_FOREACH(std::string name, rx_subdevs){
+        BOOST_FOREACH(std::string subdev, rx_subdevs){
             dboard_base::sptr rx_dboard = rx_dboard_ctor(
-                dboard_base::ctor_args_t(name, interface, rx_dboard_id, ID_NONE)
+                dboard_base::ctor_args_t(subdev, interface, rx_dboard_id, ID_NONE)
             );
             //create a rx proxy for this rx board
-            _rx_dboards[name] = subdev_proxy::sptr(
+            _rx_dboards[subdev] = subdev_proxy::sptr(
                 new subdev_proxy(rx_dboard, subdev_proxy::RX_TYPE)
             );
         }
         //make the tx subdevs
-        BOOST_FOREACH(std::string name, tx_subdevs){
+        BOOST_FOREACH(std::string subdev, tx_subdevs){
             dboard_base::sptr tx_dboard = tx_dboard_ctor(
-                dboard_base::ctor_args_t(name, interface, ID_NONE, tx_dboard_id)
+                dboard_base::ctor_args_t(subdev, interface, ID_NONE, tx_dboard_id)
             );
             //create a tx proxy for this tx board
-            _tx_dboards[name] = subdev_proxy::sptr(
+            _tx_dboards[subdev] = subdev_proxy::sptr(
                 new subdev_proxy(tx_dboard, subdev_proxy::TX_TYPE)
             );
         }
@@ -257,7 +260,7 @@ wax::obj dboard_manager_impl::get_rx_subdev(const std::string &subdev_name){
         str(boost::format("Unknown rx subdev name %s") % subdev_name)
     );
     //get a link to the rx subdev proxy
-    return wax::cast<subdev_proxy::sptr>(_rx_dboards[subdev_name])->get_link();
+    return _rx_dboards[subdev_name]->get_link();
 }
 
 wax::obj dboard_manager_impl::get_tx_subdev(const std::string &subdev_name){
@@ -265,7 +268,7 @@ wax::obj dboard_manager_impl::get_tx_subdev(const std::string &subdev_name){
         str(boost::format("Unknown tx subdev name %s") % subdev_name)
     );
     //get a link to the tx subdev proxy
-    return wax::cast<subdev_proxy::sptr>(_tx_dboards[subdev_name])->get_link();
+    return _tx_dboards[subdev_name]->get_link();
 }
 
 void dboard_manager_impl::set_nice_gpio_pins(void){
diff --git a/host/lib/usrp/usrp1e/usrp1e_impl.cpp b/host/lib/usrp/usrp1e/usrp1e_impl.cpp
index 93265ab17..441f6d060 100644
--- a/host/lib/usrp/usrp1e/usrp1e_impl.cpp
+++ b/host/lib/usrp/usrp1e/usrp1e_impl.cpp
@@ -15,18 +15,23 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include <unistd.h>
+#include <uhd/utils.hpp>
 #include <boost/format.hpp>
+#include <boost/filesystem.hpp>
 #include "usrp1e_impl.hpp"
 
 using namespace uhd;
 using namespace uhd::usrp;
 
+STATIC_BLOCK(register_usrp1e_device){
+    device::register_device(&usrp1e::discover, &usrp1e::make);
+}
+
 /***********************************************************************
  * Helper Functions
  **********************************************************************/
 static bool file_exists(const std::string &file_path){
-    return access(file_path.c_str(), F_OK) == 0;
+    return boost::filesystem::exists(file_path);
 }
 
 /***********************************************************************
@@ -40,7 +45,6 @@ device_addrs_t usrp1e::discover(const device_addr_t &device_addr){
         if (not file_exists(device_addr["node"])) return usrp1e_addrs;
         device_addr_t new_addr;
         new_addr["name"] = "USRP1E";
-        new_addr["type"] = "usrp1e";
         new_addr["node"] = device_addr["node"];
         usrp1e_addrs.push_back(new_addr);
     }
@@ -52,7 +56,6 @@ device_addrs_t usrp1e::discover(const device_addr_t &device_addr){
             if (not file_exists(node)) continue;
             device_addr_t new_addr;
             new_addr["name"] = "USRP1E";
-            new_addr["type"] = "usrp1e";
             new_addr["node"] = node;
             usrp1e_addrs.push_back(new_addr);
         }
diff --git a/host/lib/usrp/usrp2/dboard_impl.cpp b/host/lib/usrp/usrp2/dboard_impl.cpp
index 32c64f541..6d957436e 100644
--- a/host/lib/usrp/usrp2/dboard_impl.cpp
+++ b/host/lib/usrp/usrp2/dboard_impl.cpp
@@ -16,6 +16,7 @@
 //
 
 #include <uhd/utils.hpp>
+#include <boost/format.hpp>
 #include "usrp2_impl.hpp"
 #include "dboard_interface.hpp"
 
@@ -70,7 +71,7 @@ void usrp2_impl::rx_dboard_get(const wax::obj &key_, wax::obj &val){
     boost::tie(key, name) = extract_named_prop(key_);
 
     //handle the get request conditioned on the key
-    switch(wax::cast<dboard_prop_t>(key)){
+    switch(key.as<dboard_prop_t>()){
     case DBOARD_PROP_NAME:
         val = std::string("usrp2 dboard (rx unit)");
         return;
@@ -83,8 +84,8 @@ void usrp2_impl::rx_dboard_get(const wax::obj &key_, wax::obj &val){
         val = _dboard_manager->get_rx_subdev_names();
         return;
 
-    case DBOARD_PROP_CODEC:
-        throw std::runtime_error("unhandled prop in usrp2 dboard");
+    //case DBOARD_PROP_CODEC:
+    //    throw std::runtime_error("unhandled prop in usrp2 dboard");
     }
 }
 
@@ -100,7 +101,7 @@ void usrp2_impl::tx_dboard_get(const wax::obj &key_, wax::obj &val){
     boost::tie(key, name) = extract_named_prop(key_);
 
     //handle the get request conditioned on the key
-    switch(wax::cast<dboard_prop_t>(key)){
+    switch(key.as<dboard_prop_t>()){
     case DBOARD_PROP_NAME:
         val = std::string("usrp2 dboard (tx unit)");
         return;
@@ -113,8 +114,8 @@ void usrp2_impl::tx_dboard_get(const wax::obj &key_, wax::obj &val){
         val = _dboard_manager->get_tx_subdev_names();
         return;
 
-    case DBOARD_PROP_CODEC:
-        throw std::runtime_error("unhandled prop in usrp2 dboard");
+    //case DBOARD_PROP_CODEC:
+    //    throw std::runtime_error("unhandled prop in usrp2 dboard");
     }
 }
 
diff --git a/host/lib/usrp/usrp2/dsp_impl.cpp b/host/lib/usrp/usrp2/dsp_impl.cpp
index 22c00d99a..7520c1757 100644
--- a/host/lib/usrp/usrp2/dsp_impl.cpp
+++ b/host/lib/usrp/usrp2/dsp_impl.cpp
@@ -16,11 +16,15 @@
 //
 
 #include <uhd/utils.hpp>
+#include <boost/format.hpp>
 #include <boost/assign/list_of.hpp>
 #include "usrp2_impl.hpp"
 
 using namespace uhd;
 
+static const size_t default_decim = 16;
+static const size_t default_interp = 16;
+
 /***********************************************************************
  * DDC Helper Methods
  **********************************************************************/
@@ -36,6 +40,10 @@ static uint32_t calculate_freq_word_and_update_actual_freq(freq_t &freq, freq_t
     return freq_word;
 }
 
+static uint32_t calculate_iq_scale_word(int16_t i, int16_t q){
+    return (uint16_t(i) << 16) | (uint16_t(q) << 0);
+}
+
 void usrp2_impl::init_ddc_config(void){
     //create the ddc in the rx dsp dict
     _rx_dsps["ddc0"] = wax_obj_proxy(
@@ -44,7 +52,7 @@ void usrp2_impl::init_ddc_config(void){
     );
 
     //initial config and update
-    _ddc_decim = 16;
+    _ddc_decim = default_decim;
     _ddc_freq = 0;
     update_ddc_config();
 
@@ -61,6 +69,10 @@ void usrp2_impl::update_ddc_config(void){
         calculate_freq_word_and_update_actual_freq(_ddc_freq, get_master_clock_freq())
     );
     out_data.data.ddc_args.decim = htonl(_ddc_decim);
+    static const uint32_t default_rx_scale_iq = 1024;
+    out_data.data.ddc_args.scale_iq = htonl(
+        calculate_iq_scale_word(default_rx_scale_iq, default_rx_scale_iq)
+    );
 
     //send and recv
     usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
@@ -74,6 +86,7 @@ void usrp2_impl::update_ddc_enabled(void){
     out_data.data.streaming.enabled = (_ddc_enabled)? 1 : 0;
     out_data.data.streaming.secs =  htonl(_ddc_stream_at.secs);
     out_data.data.streaming.ticks = htonl(_ddc_stream_at.ticks);
+    out_data.data.streaming.samples = htonl(_max_rx_samples_per_packet);
 
     //send and recv
     usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
@@ -89,7 +102,7 @@ void usrp2_impl::update_ddc_enabled(void){
 void usrp2_impl::ddc_get(const wax::obj &key, wax::obj &val){
     //handle the case where the key is an expected dsp property
     if (key.type() == typeid(dsp_prop_t)){
-        switch(wax::cast<dsp_prop_t>(key)){
+        switch(key.as<dsp_prop_t>()){
         case DSP_PROP_NAME:
             val = std::string("usrp2 ddc0");
             return;
@@ -98,7 +111,7 @@ void usrp2_impl::ddc_get(const wax::obj &key, wax::obj &val){
                 prop_names_t others = boost::assign::list_of
                     ("rate")
                     ("decim")
-                    ("decim_rates")
+                    ("decims")
                     ("freq")
                     ("enabled")
                     ("stream_at")
@@ -110,7 +123,7 @@ void usrp2_impl::ddc_get(const wax::obj &key, wax::obj &val){
     }
 
     //handle string-based properties specific to this dsp
-    std::string key_name = wax::cast<std::string>(key);
+    std::string key_name = key.as<std::string>();
     if (key_name == "rate"){
         val = get_master_clock_freq();
         return;
@@ -119,7 +132,7 @@ void usrp2_impl::ddc_get(const wax::obj &key, wax::obj &val){
         val = _ddc_decim;
         return;
     }
-    else if (key_name == "decim_rates"){
+    else if (key_name == "decims"){
         val = _allowed_decim_and_interp_rates;
         return;
     }
@@ -139,20 +152,19 @@ void usrp2_impl::ddc_get(const wax::obj &key, wax::obj &val){
 
 void usrp2_impl::ddc_set(const wax::obj &key, const wax::obj &val){
     //handle string-based properties specific to this dsp
-    std::string key_name = wax::cast<std::string>(key);
+    std::string key_name = key.as<std::string>();
     if (key_name == "decim"){
-        size_t new_decim = wax::cast<size_t>(val);
-        ASSERT_THROW(std::has(
-            _allowed_decim_and_interp_rates.begin(),
-            _allowed_decim_and_interp_rates.end(),
-            new_decim
-        ));
+        size_t new_decim = val.as<size_t>();
+        assert_has(
+            _allowed_decim_and_interp_rates,
+            new_decim, "usrp2 decimation"
+        );
         _ddc_decim = new_decim; //shadow
         update_ddc_config();
         return;
     }
     else if (key_name == "freq"){
-        freq_t new_freq = wax::cast<freq_t>(val);
+        freq_t new_freq = val.as<freq_t>();
         ASSERT_THROW(new_freq <= get_master_clock_freq()/2.0);
         ASSERT_THROW(new_freq >= -get_master_clock_freq()/2.0);
         _ddc_freq = new_freq; //shadow
@@ -160,13 +172,13 @@ void usrp2_impl::ddc_set(const wax::obj &key, const wax::obj &val){
         return;
     }
     else if (key_name == "enabled"){
-        bool new_enabled = wax::cast<bool>(val);
+        bool new_enabled = val.as<bool>();
         _ddc_enabled = new_enabled; //shadow
         update_ddc_enabled();
         return;
     }
     else if (key_name == "stream_at"){
-        time_spec_t new_stream_at = wax::cast<time_spec_t>(val);
+        time_spec_t new_stream_at = val.as<time_spec_t>();
         _ddc_stream_at = new_stream_at; //shadow
         //update_ddc_enabled(); //dont update from here
         return;
@@ -188,7 +200,7 @@ void usrp2_impl::init_duc_config(void){
     );
 
     //initial config and update
-    _duc_interp = 16;
+    _duc_interp = default_interp;
     _duc_freq = 0;
     update_duc_config();
 }
@@ -209,7 +221,9 @@ void usrp2_impl::update_duc_config(void){
         calculate_freq_word_and_update_actual_freq(_duc_freq, get_master_clock_freq())
     );
     out_data.data.duc_args.interp = htonl(_duc_interp);
-    out_data.data.duc_args.scale_iq = htonl(scale);
+    out_data.data.duc_args.scale_iq = htonl(
+        calculate_iq_scale_word(scale, scale)
+    );
 
     //send and recv
     usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
@@ -222,7 +236,7 @@ void usrp2_impl::update_duc_config(void){
 void usrp2_impl::duc_get(const wax::obj &key, wax::obj &val){
     //handle the case where the key is an expected dsp property
     if (key.type() == typeid(dsp_prop_t)){
-        switch(wax::cast<dsp_prop_t>(key)){
+        switch(key.as<dsp_prop_t>()){
         case DSP_PROP_NAME:
             val = std::string("usrp2 duc0");
             return;
@@ -231,7 +245,7 @@ void usrp2_impl::duc_get(const wax::obj &key, wax::obj &val){
                 prop_names_t others = boost::assign::list_of
                     ("rate")
                     ("interp")
-                    ("interp_rates")
+                    ("interps")
                     ("freq")
                 ;
                 val = others;
@@ -241,7 +255,7 @@ void usrp2_impl::duc_get(const wax::obj &key, wax::obj &val){
     }
 
     //handle string-based properties specific to this dsp
-    std::string key_name = wax::cast<std::string>(key);
+    std::string key_name = key.as<std::string>();
     if (key_name == "rate"){
         val = get_master_clock_freq();
         return;
@@ -250,7 +264,7 @@ void usrp2_impl::duc_get(const wax::obj &key, wax::obj &val){
         val = _duc_interp;
         return;
     }
-    else if (key_name == "interp_rates"){
+    else if (key_name == "interps"){
         val = _allowed_decim_and_interp_rates;
         return;
     }
@@ -266,20 +280,19 @@ void usrp2_impl::duc_get(const wax::obj &key, wax::obj &val){
 
 void usrp2_impl::duc_set(const wax::obj &key, const wax::obj &val){
     //handle string-based properties specific to this dsp
-    std::string key_name = wax::cast<std::string>(key);
+    std::string key_name = key.as<std::string>();
     if (key_name == "interp"){
-        size_t new_interp = wax::cast<size_t>(val);
-        ASSERT_THROW(std::has(
-            _allowed_decim_and_interp_rates.begin(),
-            _allowed_decim_and_interp_rates.end(),
-            new_interp
-        ));
+        size_t new_interp = val.as<size_t>();
+        assert_has(
+            _allowed_decim_and_interp_rates,
+            new_interp, "usrp2 interpolation"
+        );
         _duc_interp = new_interp; //shadow
         update_duc_config();
         return;
     }
     else if (key_name == "freq"){
-        freq_t new_freq = wax::cast<freq_t>(val);
+        freq_t new_freq = val.as<freq_t>();
         ASSERT_THROW(new_freq <= get_master_clock_freq()/2.0);
         ASSERT_THROW(new_freq >= -get_master_clock_freq()/2.0);
         _duc_freq = new_freq; //shadow
diff --git a/host/lib/usrp/usrp2/fw_common.h b/host/lib/usrp/usrp2/fw_common.h
index 3def8ddaa..10c1ef8cf 100644
--- a/host/lib/usrp/usrp2/fw_common.h
+++ b/host/lib/usrp/usrp2/fw_common.h
@@ -27,6 +27,10 @@
 extern "C" {
 #endif
 
+// size of the vrt header and trailer to the host
+#define USRP2_HOST_RX_VRT_HEADER_WORDS32 5
+#define USRP2_HOST_RX_VRT_TRAILER_WORDS32 1 //FIXME fpga sets wrong header size when no trailer present
+
 // udp ports for the usrp2 communication
 // Dynamic and/or private ports: 49152-65535
 #define USRP2_UDP_CTRL_PORT 49152
@@ -87,6 +91,9 @@ typedef enum{
     USRP2_CTRL_ID_SETUP_THIS_DUC_FOR_ME_BRO,
     USRP2_CTRL_ID_TOTALLY_SETUP_THE_DUC_DUDE,
 
+    USRP2_CTRL_ID_GOT_A_NEW_TIME_FOR_YOU_BRO,
+    USRP2_CTRL_ID_SWEET_I_GOT_THAT_TIME_DUDE,
+
     USRP2_CTRL_ID_PEACE_OUT
 
 } usrp2_ctrl_id_t;
@@ -168,18 +175,25 @@ typedef struct{
         struct {
             uint32_t freq_word;
             uint32_t decim;
+            uint32_t scale_iq;
         } ddc_args;
         struct {
             uint8_t enabled;
             uint8_t _pad[3];
             uint32_t secs;
             uint32_t ticks;
+            uint32_t samples;
         } streaming;
         struct {
             uint32_t freq_word;
             uint32_t interp;
             uint32_t scale_iq;
         } duc_args;
+        struct {
+            uint32_t secs;
+            uint32_t ticks;
+            uint8_t now;
+        } time_args;
     } data;
 } usrp2_ctrl_data_t;
 
diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
index 43334ddc6..cc7746720 100644
--- a/host/lib/usrp/usrp2/io_impl.cpp
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -16,12 +16,13 @@
 //
 
 #include <complex>
-#include <boost/shared_array.hpp>
 #include <boost/format.hpp>
 #include "usrp2_impl.hpp"
 
 using namespace uhd;
 using namespace uhd::usrp;
+using namespace uhd::transport;
+namespace asio = boost::asio;
 
 /***********************************************************************
  * Constants
@@ -29,214 +30,228 @@ using namespace uhd::usrp;
 typedef std::complex<float>   fc32_t;
 typedef std::complex<int16_t> sc16_t;
 
-static const float float_scale_factor = pow(2.0, 15);
-
-//max length with header, stream id, seconds, fractional seconds
-static const size_t max_vrt_header_words = 5;
+static const float shorts_per_float = pow(2.0, 15);
+static const float floats_per_short = 1.0/shorts_per_float;
 
 /***********************************************************************
  * Helper Functions
  **********************************************************************/
-static inline void host_floats_to_usrp2_shorts(
-    int16_t *usrp2_shorts,
-    const float *host_floats,
-    size_t num_samps
-){
-    for(size_t i = 0; i < num_samps; i++){
-        usrp2_shorts[i] = htons(int16_t(host_floats[i]*float_scale_factor));
-    }
+void usrp2_impl::io_init(void){
+    //initially empty copy buffer
+    _rx_copy_buff = asio::buffer("", 0);
+
+    //send a small data packet so the usrp2 knows the udp source port
+    uint32_t zero_data = 0;
+    _data_transport->send(asio::buffer(&zero_data, sizeof(zero_data)));
+}
+
+#define unrolled_loop(__i, __len, __inst) {\
+    size_t __i = 0; \
+    while(__i < (__len & ~0x7)){ \
+        __inst; __i++; __inst; __i++; \
+        __inst; __i++; __inst; __i++; \
+        __inst; __i++; __inst; __i++; \
+        __inst; __i++; __inst; __i++; \
+    } \
+    while(__i < __len){ \
+        __inst; __i++;\
+    } \
 }
 
-static inline void usrp2_shorts_to_host_floats(
-    float *host_floats,
-    const int16_t *usrp2_shorts,
+// set a boolean flag that indicates the endianess
+#ifdef HAVE_BIG_ENDIAN
+static const bool is_big_endian = true;
+#else
+static const bool is_big_endian = false;
+#endif
+
+static inline void host_floats_to_usrp2_items(
+    uint32_t *usrp2_items,
+    const fc32_t *host_floats,
     size_t num_samps
 ){
-    for(size_t i = 0; i < num_samps; i++){
-        host_floats[i] = float(ntohs(usrp2_shorts[i])/float_scale_factor);
-    }
+    unrolled_loop(i, num_samps,{
+        uint16_t real = host_floats[i].real()*shorts_per_float;
+        uint16_t imag = host_floats[i].imag()*shorts_per_float;
+        usrp2_items[i] = htonl((real << 16) | (imag << 0));
+    });
 }
 
-static inline void host_shorts_to_usrp2_shorts(
-    int16_t *usrp2_shorts,
-    const int16_t *host_shorts,
+static inline void usrp2_items_to_host_floats(
+    fc32_t *host_floats,
+    const uint32_t *usrp2_items,
     size_t num_samps
 ){
-    for(size_t i = 0; i < num_samps; i++){
-        usrp2_shorts[i] = htons(host_shorts[i]);
-    }
+    unrolled_loop(i, num_samps,{
+        uint32_t item = ntohl(usrp2_items[i]);
+        int16_t real = item >> 16;
+        int16_t imag = item >> 0;
+        host_floats[i] = fc32_t(real*floats_per_short, imag*floats_per_short);
+    });
 }
 
-static inline void usrp2_shorts_to_host_shorts(
-    int16_t *host_shorts,
-    const int16_t *usrp2_shorts,
+static inline void host_items_to_usrp2_items(
+    uint32_t *usrp2_items,
+    const uint32_t *host_items,
     size_t num_samps
 ){
-    for(size_t i = 0; i < num_samps; i++){
-        host_shorts[i] = ntohs(usrp2_shorts[i]);
+    if (is_big_endian){
+        std::memcpy(usrp2_items, host_items, num_samps*sizeof(uint32_t));
+    }
+    else{
+        unrolled_loop(i, num_samps, usrp2_items[i] = htonl(host_items[i]));
     }
 }
 
-/***********************************************************************
- * Send Raw Data
- **********************************************************************/
-size_t usrp2_impl::send_raw(
-    const boost::asio::const_buffer &buff,
-    const uhd::metadata_t &metadata
+static inline void usrp2_items_to_host_items(
+    uint32_t *host_items,
+    const uint32_t *usrp2_items,
+    size_t num_samps
 ){
-    std::vector<boost::asio::const_buffer> buffs(2);
-    uint32_t vrt_hdr[max_vrt_header_words];
-    uint32_t vrt_hdr_flags = 0;
-    size_t num_vrt_hdr_words = 1;
-
-    //load the vrt header and flags
-    if(metadata.has_stream_id){
-        vrt_hdr_flags |= (0x1 << 28); //IF Data packet with Stream Identifier
-        vrt_hdr[num_vrt_hdr_words++] = htonl(metadata.stream_id);
+    if (is_big_endian){
+        std::memcpy(host_items, usrp2_items, num_samps*sizeof(uint32_t));
     }
-    if(metadata.has_time_spec){
-        vrt_hdr_flags |= (0x3 << 22) | (0x1 << 20); //TSI: Other, TSF: Sample Count Timestamp
-        vrt_hdr[num_vrt_hdr_words++] = htonl(metadata.time_spec.secs);
-        vrt_hdr[num_vrt_hdr_words++] = htonl(metadata.time_spec.ticks);
-        vrt_hdr[num_vrt_hdr_words++] = 0; //unused part of fractional seconds
+    else{
+        unrolled_loop(i, num_samps, host_items[i] = ntohl(usrp2_items[i]));
     }
-    vrt_hdr_flags |= (metadata.start_of_burst)? (0x1 << 25) : 0;
-    vrt_hdr_flags |= (metadata.end_of_burst)?   (0x1 << 24) : 0;
-
-    //fill in complete header word
-    vrt_hdr[0] = htonl(vrt_hdr_flags |
-        ((_stream_id_to_packet_seq[metadata.stream_id]++ & 0xf) << 16) |
-        ((boost::asio::buffer_size(buff)/sizeof(uint32_t)) & 0xffff)
-    );
-
-    //load the buffer vector
-    size_t vrt_hdr_size = num_vrt_hdr_words*sizeof(uint32_t);
-    buffs[0] = boost::asio::buffer(&vrt_hdr, vrt_hdr_size);
-    buffs[1] = buff;
-
-    //send and return number of samples
-    return (_data_transport->send(buffs) - vrt_hdr_size)/sizeof(sc16_t);
 }
 
 /***********************************************************************
  * Receive Raw Data
  **********************************************************************/
-size_t usrp2_impl::recv_raw(
-    const boost::asio::mutable_buffer &buff,
-    uhd::metadata_t &metadata
-){
-    //load the buffer vector
-    std::vector<boost::asio::mutable_buffer> buffs(2);
-    uint32_t vrt_hdr[max_vrt_header_words];
-    buffs[0] = boost::asio::buffer(vrt_hdr, max_vrt_header_words);
-    buffs[1] = buff;
+void usrp2_impl::recv_raw(rx_metadata_t &metadata){
+    //do a receive
+    _rx_smart_buff = _data_transport->recv();
 
-    //receive into the buffers
-    size_t bytes_recvd = _data_transport->recv(buffs);
+    //unpack the vrt header
+    size_t num_packet_words32 = asio::buffer_size(_rx_smart_buff->get())/sizeof(uint32_t);
+    if (num_packet_words32 == 0){
+        _rx_copy_buff = boost::asio::buffer("", 0);
+        return; //must exit here after setting the buffer
+    }
+    const uint32_t *vrt_hdr = asio::buffer_cast<const uint32_t *>(_rx_smart_buff->get());
+    size_t num_header_words32_out, num_payload_words32_out, packet_count_out;
+    try{
+        vrt::unpack(
+            metadata,                //output
+            vrt_hdr,                 //input
+            num_header_words32_out,  //output
+            num_payload_words32_out, //output
+            num_packet_words32,      //input
+            packet_count_out         //output
+        );
+    }catch(const std::exception &e){
+        std::cerr << "bad vrt header: " << e.what() << std::endl;
+        _rx_copy_buff = boost::asio::buffer("", 0);
+        return; //must exit here after setting the buffer
+    }
 
-    //failure case
-    if (bytes_recvd < max_vrt_header_words*sizeof(uint32_t)) return 0;
+    //handle the packet count / sequence number
+    size_t expected_packet_count = _rx_stream_id_to_packet_seq[metadata.stream_id];
+    if (packet_count_out != expected_packet_count){
+        std::cerr << "bad packet count: " << packet_count_out << std::endl;
+    }
+    _rx_stream_id_to_packet_seq[metadata.stream_id] = (packet_count_out+1)%16;
 
-    //unpack the vrt header
-    metadata = uhd::metadata_t();
-    uint32_t vrt_header = ntohl(vrt_hdr[0]);
-    metadata.has_stream_id = true;
-    metadata.stream_id = ntohl(vrt_hdr[1]);
-    metadata.has_time_spec = true;
-    metadata.time_spec.secs = ntohl(vrt_hdr[2]);
-    metadata.time_spec.ticks = ntohl(vrt_hdr[3]);
-
-    //return the number of samples received
-    size_t num_words = vrt_header & 0xffff;
-    return (num_words*sizeof(uint32_t))/sizeof(sc16_t);
+    //setup the rx buffer to point to the data
+    _rx_copy_buff = asio::buffer(
+        vrt_hdr + num_header_words32_out,
+        num_payload_words32_out*sizeof(uint32_t)
+    );
 }
 
 /***********************************************************************
  * Send Data
  **********************************************************************/
 size_t usrp2_impl::send(
-    const boost::asio::const_buffer &buff,
-    const uhd::metadata_t &metadata,
+    const asio::const_buffer &buff,
+    const tx_metadata_t &metadata,
     const std::string &type
 ){
-    if (type == "fc32"){
-        size_t num_samps = boost::asio::buffer_size(buff)/sizeof(fc32_t);
-        boost::shared_array<sc16_t> raw_mem(new sc16_t[num_samps]);
-        boost::asio::mutable_buffer raw_buff(raw_mem.get(), num_samps*sizeof(sc16_t));
-
-        host_floats_to_usrp2_shorts(
-            boost::asio::buffer_cast<int16_t*>(raw_buff),
-            boost::asio::buffer_cast<const float*>(buff),
-            num_samps*2 //double for complex
-        );
-
-        return send_raw(raw_buff, metadata);
+    uint32_t tx_mem[_mtu/sizeof(uint32_t)];
+    uint32_t *items = tx_mem + vrt::max_header_words32; //offset for data
+    size_t num_samps = _max_tx_samples_per_packet;
+
+    //calculate the number of samples to be copied
+    //and copy the samples into the send buffer
+    if (type == "32fc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(fc32_t), num_samps);
+        host_floats_to_usrp2_items(items, asio::buffer_cast<const fc32_t*>(buff), num_samps);
+    }
+    else if (type == "16sc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(sc16_t), num_samps);
+        host_items_to_usrp2_items(items, asio::buffer_cast<const uint32_t*>(buff), num_samps);
+    }
+    else{
+        throw std::runtime_error(str(boost::format("usrp2 send: cannot handle type \"%s\"") % type));
     }
 
-    if (type == "sc16"){
-        #ifdef HAVE_BIG_ENDIAN
-        return send_raw(buff, metadata);
-        #else
-        size_t num_samps = boost::asio::buffer_size(buff)/sizeof(sc16_t);
-        boost::shared_array<sc16_t> raw_mem(new sc16_t[num_samps]);
-        boost::asio::mutable_buffer raw_buff(raw_mem.get(), num_samps*sizeof(sc16_t));
-
-        host_shorts_to_usrp2_shorts(
-            boost::asio::buffer_cast<int16_t*>(raw_buff),
-            boost::asio::buffer_cast<const int16_t*>(buff),
-            num_samps*2 //double for complex
-        );
+    uint32_t vrt_hdr[vrt::max_header_words32];
+    size_t num_header_words32, num_packet_words32;
+    size_t packet_count = _tx_stream_id_to_packet_seq[metadata.stream_id]++;
+
+    //pack metadata into a vrt header
+    vrt::pack(
+        metadata,            //input
+        vrt_hdr,             //output
+        num_header_words32,  //output
+        num_samps,           //input
+        num_packet_words32,  //output
+        packet_count         //input
+    );
 
-        return send_raw(raw_buff, metadata);
-        #endif
-    }
+    //copy in the vrt header (yes we left space)
+    items -= num_header_words32;
+    std::memcpy(items, vrt_hdr, num_header_words32*sizeof(uint32_t));
 
-    throw std::runtime_error(str(boost::format("usrp2 send: cannot handle type \"%s\"") % type));
+    //send and return number of samples
+    _data_transport->send(asio::buffer(items, num_packet_words32*sizeof(uint32_t)));
+    return num_samps;
 }
 
 /***********************************************************************
  * Receive Data
  **********************************************************************/
 size_t usrp2_impl::recv(
-    const boost::asio::mutable_buffer &buff,
-    uhd::metadata_t &metadata,
+    const asio::mutable_buffer &buff,
+    rx_metadata_t &metadata,
     const std::string &type
 ){
-    if (type == "fc32"){
-        size_t num_samps = boost::asio::buffer_size(buff)/sizeof(fc32_t);
-        boost::shared_array<sc16_t> raw_mem(new sc16_t[num_samps]);
-        boost::asio::mutable_buffer raw_buff(raw_mem.get(), num_samps*sizeof(sc16_t));
-
-        num_samps = recv_raw(raw_buff, metadata);
-
-        usrp2_shorts_to_host_floats(
-            boost::asio::buffer_cast<float*>(buff),
-            boost::asio::buffer_cast<const int16_t*>(raw_buff),
-            num_samps*2 //double for complex
-        );
-
-        return num_samps;
+    //perform a receive if no rx data is waiting to be copied
+    if (asio::buffer_size(_rx_copy_buff) == 0){
+        recv_raw(metadata);
+    }
+    //otherwise flag the metadata to show that is is a fragment
+    else{
+        metadata = rx_metadata_t();
+        metadata.is_fragment = true;
     }
 
-    if (type == "sc16"){
-        #ifdef HAVE_BIG_ENDIAN
-        return recv_raw(buff, metadata);
-        #else
-        size_t num_samps = boost::asio::buffer_size(buff)/sizeof(sc16_t);
-        boost::shared_array<sc16_t> raw_mem(new sc16_t[num_samps]);
-        boost::asio::mutable_buffer raw_buff(raw_mem.get(), num_samps*sizeof(sc16_t));
-
-        num_samps = recv_raw(raw_buff, metadata);
-
-        usrp2_shorts_to_host_shorts(
-            boost::asio::buffer_cast<int16_t*>(buff),
-            boost::asio::buffer_cast<const int16_t*>(raw_buff),
-            num_samps*2 //double for complex
-        );
-
-        return num_samps;
-        #endif
+    //extract the number of samples available to copy
+    //and a pointer into the usrp2 received items memory
+    size_t bytes_to_copy = asio::buffer_size(_rx_copy_buff);
+    if (bytes_to_copy == 0) return 0; //nothing to receive
+    size_t num_samps = bytes_to_copy/sizeof(uint32_t);
+    const uint32_t *items = asio::buffer_cast<const uint32_t*>(_rx_copy_buff);
+
+    //calculate the number of samples to be copied
+    //and copy the samples from the recv buffer
+    if (type == "32fc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(fc32_t), num_samps);
+        usrp2_items_to_host_floats(asio::buffer_cast<fc32_t*>(buff), items, num_samps);
+    }
+    else if (type == "16sc"){
+        num_samps = std::min(asio::buffer_size(buff)/sizeof(sc16_t), num_samps);
+        usrp2_items_to_host_items(asio::buffer_cast<uint32_t*>(buff), items, num_samps);
     }
+    else{
+        throw std::runtime_error(str(boost::format("usrp2 recv: cannot handle type \"%s\"") % type));
+    }
+
+    //update the rx copy buffer to reflect the bytes copied
+    _rx_copy_buff = asio::buffer(
+        items + num_samps, bytes_to_copy - num_samps*sizeof(uint32_t)
+    );
 
-    throw std::runtime_error(str(boost::format("usrp2 recv: cannot handle type \"%s\"") % type));
+    return num_samps;
 }
diff --git a/host/lib/usrp/usrp2/mboard_impl.cpp b/host/lib/usrp/usrp2/mboard_impl.cpp
index cc73b229c..4b15c7f3e 100644
--- a/host/lib/usrp/usrp2/mboard_impl.cpp
+++ b/host/lib/usrp/usrp2/mboard_impl.cpp
@@ -16,6 +16,7 @@
 //
 
 #include <uhd/utils.hpp>
+#include <boost/assign/list_of.hpp>
 #include "usrp2_impl.hpp"
 
 using namespace uhd;
@@ -28,6 +29,10 @@ void usrp2_impl::mboard_init(void){
         boost::bind(&usrp2_impl::mboard_get, this, _1, _2),
         boost::bind(&usrp2_impl::mboard_set, this, _1, _2)
     );
+
+    //set the time on the usrp2 as close as possible to the system utc time
+    boost::posix_time::ptime now(boost::posix_time::microsec_clock::universal_time());
+    set_time_spec(time_spec_t(now, get_master_clock_freq()), true);
 }
 
 void usrp2_impl::init_clock_config(void){
@@ -64,6 +69,19 @@ void usrp2_impl::update_clock_config(void){
     ASSERT_THROW(htonl(in_data.id) == USRP2_CTRL_ID_GOT_THE_NEW_CLOCK_CONFIG_DUDE);
 }
 
+void usrp2_impl::set_time_spec(const time_spec_t &time_spec, bool now){
+    //setup the out data
+    usrp2_ctrl_data_t out_data;
+    out_data.id = htonl(USRP2_CTRL_ID_GOT_A_NEW_TIME_FOR_YOU_BRO);
+    out_data.data.time_args.secs  = htonl(time_spec.secs);
+    out_data.data.time_args.ticks = htonl(time_spec.ticks);
+    out_data.data.time_args.now   = (now)? 1 : 0;
+
+    //send and recv
+    usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
+    ASSERT_THROW(htonl(in_data.id) == USRP2_CTRL_ID_SWEET_I_GOT_THAT_TIME_DUDE);
+}
+
 /***********************************************************************
  * MBoard Get Properties
  **********************************************************************/
@@ -71,17 +89,54 @@ void usrp2_impl::mboard_get(const wax::obj &key_, wax::obj &val){
     wax::obj key; std::string name;
     boost::tie(key, name) = extract_named_prop(key_);
 
+    //handle the other props
+    if (key.type() == typeid(std::string)){
+        if (key.as<std::string>() == "mac-addr"){
+            //setup the out data
+            usrp2_ctrl_data_t out_data;
+            out_data.id = htonl(USRP2_CTRL_ID_GIVE_ME_YOUR_MAC_ADDR_BRO);
+
+            //send and recv
+            usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
+            ASSERT_THROW(htonl(in_data.id) == USRP2_CTRL_ID_THIS_IS_MY_MAC_ADDR_DUDE);
+
+            //extract the address
+            val = reinterpret_cast<mac_addr_t*>(in_data.data.mac_addr)->to_string();
+            return;
+        }
+
+        if (key.as<std::string>() == "ip-addr"){
+            //setup the out data
+            usrp2_ctrl_data_t out_data;
+            out_data.id = htonl(USRP2_CTRL_ID_GIVE_ME_YOUR_IP_ADDR_BRO);
+
+            //send and recv
+            usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
+            ASSERT_THROW(htonl(in_data.id) == USRP2_CTRL_ID_THIS_IS_MY_IP_ADDR_DUDE);
+
+            //extract the address
+            val = boost::asio::ip::address_v4(ntohl(in_data.data.ip_addr)).to_string();
+            return;
+        }
+    }
+
     //handle the get request conditioned on the key
-    switch(wax::cast<mboard_prop_t>(key)){
+    switch(key.as<mboard_prop_t>()){
     case MBOARD_PROP_NAME:
         val = std::string("usrp2 mboard");
         return;
 
-    case MBOARD_PROP_OTHERS:
-        val = prop_names_t(); //empty other props
+    case MBOARD_PROP_OTHERS:{
+            prop_names_t others = boost::assign::list_of
+                ("mac-addr")
+                ("ip-addr")
+            ;
+            val = others;
+        }
         return;
 
     case MBOARD_PROP_RX_DBOARD:
+        ASSERT_THROW(_rx_dboards.has_key(name));
         val = _rx_dboards[name].get_link();
         return;
 
@@ -90,6 +145,7 @@ void usrp2_impl::mboard_get(const wax::obj &key_, wax::obj &val){
         return;
 
     case MBOARD_PROP_TX_DBOARD:
+        ASSERT_THROW(_tx_dboards.has_key(name));
         val = _tx_dboards[name].get_link();
         return;
 
@@ -97,17 +153,12 @@ void usrp2_impl::mboard_get(const wax::obj &key_, wax::obj &val){
         val = prop_names_t(_tx_dboards.get_keys());
         return;
 
-    case MBOARD_PROP_MTU:
-        // FIXME we dont know the real MTU...
-        // give them something to fragment about
-        val = size_t(1500);
-        return;
-
     case MBOARD_PROP_CLOCK_RATE:
         val = freq_t(get_master_clock_freq());
         return;
 
     case MBOARD_PROP_RX_DSP:
+        ASSERT_THROW(_rx_dsps.has_key(name));
         val = _rx_dsps[name].get_link();
         return;
 
@@ -116,6 +167,7 @@ void usrp2_impl::mboard_get(const wax::obj &key_, wax::obj &val){
         return;
 
     case MBOARD_PROP_TX_DSP:
+        ASSERT_THROW(_tx_dsps.has_key(name));
         val = _tx_dsps[name].get_link();
         return;
 
@@ -154,36 +206,73 @@ void usrp2_impl::mboard_get(const wax::obj &key_, wax::obj &val){
  * MBoard Set Properties
  **********************************************************************/
 void usrp2_impl::mboard_set(const wax::obj &key, const wax::obj &val){
+    //handle the other props
+    if (key.type() == typeid(std::string)){
+        if (key.as<std::string>() == "mac-addr"){
+            //setup the out data
+            usrp2_ctrl_data_t out_data;
+            out_data.id = htonl(USRP2_CTRL_ID_HERE_IS_A_NEW_MAC_ADDR_BRO);
+            mac_addr_t mac_addr(val.as<std::string>());
+            std::memcpy(out_data.data.mac_addr, &mac_addr, sizeof(mac_addr_t));
+
+            //send and recv
+            usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
+            ASSERT_THROW(htonl(in_data.id) == USRP2_CTRL_ID_THIS_IS_MY_MAC_ADDR_DUDE);
+            return;
+        }
+
+        if (key.as<std::string>() == "ip-addr"){
+            //setup the out data
+            usrp2_ctrl_data_t out_data;
+            out_data.id = htonl(USRP2_CTRL_ID_HERE_IS_A_NEW_IP_ADDR_BRO);
+            out_data.data.ip_addr = htonl(boost::asio::ip::address_v4::from_string(val.as<std::string>()).to_ulong());
+
+            //send and recv
+            usrp2_ctrl_data_t in_data = ctrl_send_and_recv(out_data);
+            ASSERT_THROW(htonl(in_data.id) == USRP2_CTRL_ID_THIS_IS_MY_IP_ADDR_DUDE);
+            return;
+        }
+    }
+
     //handle the get request conditioned on the key
-    switch(wax::cast<mboard_prop_t>(key)){
+    switch(key.as<mboard_prop_t>()){
 
     case MBOARD_PROP_PPS_SOURCE:{
-            std::string name = wax::cast<std::string>(val);
-            ASSERT_THROW(_pps_source_dict.has_key(name));
+            std::string name = val.as<std::string>();
+            assert_has(_pps_source_dict.get_keys(), name, "usrp2 pps source");
             _pps_source = name; //shadow
             update_clock_config();
         }
         return;
 
     case MBOARD_PROP_PPS_POLARITY:{
-            std::string name = wax::cast<std::string>(val);
-            ASSERT_THROW(_pps_polarity_dict.has_key(name));
+            std::string name = val.as<std::string>();
+            assert_has(_pps_polarity_dict.get_keys(), name, "usrp2 pps polarity");
             _pps_polarity = name; //shadow
             update_clock_config();
         }
         return;
 
     case MBOARD_PROP_REF_SOURCE:{
-            std::string name = wax::cast<std::string>(val);
-            ASSERT_THROW(_ref_source_dict.has_key(name));
+            std::string name = val.as<std::string>();
+            assert_has(_ref_source_dict.get_keys(), name, "usrp2 reference source");
             _ref_source = name; //shadow
             update_clock_config();
         }
         return;
 
+    case MBOARD_PROP_TIME_NOW:{
+        set_time_spec(val.as<time_spec_t>(), true);
+        return;
+    }
+
+    case MBOARD_PROP_TIME_NEXT_PPS:{
+        set_time_spec(val.as<time_spec_t>(), false);
+        return;
+    }
+
     case MBOARD_PROP_NAME:
     case MBOARD_PROP_OTHERS:
-    case MBOARD_PROP_MTU:
     case MBOARD_PROP_CLOCK_RATE:
     case MBOARD_PROP_RX_DSP:
     case MBOARD_PROP_RX_DSP_NAMES:
@@ -195,8 +284,6 @@ void usrp2_impl::mboard_set(const wax::obj &key, const wax::obj &val){
     case MBOARD_PROP_TX_DBOARD_NAMES:
     case MBOARD_PROP_PPS_SOURCE_NAMES:
     case MBOARD_PROP_REF_SOURCE_NAMES:
-    case MBOARD_PROP_TIME_NOW:
-    case MBOARD_PROP_TIME_NEXT_PPS:
         throw std::runtime_error("Error: trying to set read-only property on usrp2 mboard");
 
     }
diff --git a/host/lib/usrp/usrp2/usrp2_impl.cpp b/host/lib/usrp/usrp2/usrp2_impl.cpp
index 5aa5d6e8d..e1371a094 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.cpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.cpp
@@ -23,6 +23,12 @@
 
 using namespace uhd;
 using namespace uhd::usrp;
+using namespace uhd::transport;
+namespace asio = boost::asio;
+
+STATIC_BLOCK(register_usrp2_device){
+    device::register_device(&usrp2::discover, &usrp2::make);
+}
 
 /***********************************************************************
  * Discovery over the udp transport
@@ -30,30 +36,26 @@ using namespace uhd::usrp;
 uhd::device_addrs_t usrp2::discover(const device_addr_t &hint){
     device_addrs_t usrp2_addrs;
 
+    if (not hint.has_key("addr")) return usrp2_addrs;
+
     //create a udp transport to communicate
     //TODO if an addr is not provided, search all interfaces?
     std::string ctrl_port = boost::lexical_cast<std::string>(USRP2_UDP_CTRL_PORT);
-    transport::udp::sptr udp_transport = \
-        transport::udp::make(hint["addr"], ctrl_port, true);
+    udp_simple::sptr udp_transport = udp_simple::make_broadcast(
+        hint["addr"], ctrl_port
+    );
 
     //send a hello control packet
     usrp2_ctrl_data_t ctrl_data_out;
     ctrl_data_out.id = htonl(USRP2_CTRL_ID_GIVE_ME_YOUR_IP_ADDR_BRO);
     udp_transport->send(boost::asio::buffer(&ctrl_data_out, sizeof(ctrl_data_out)));
 
-    //loop and recieve until the time is up
-    size_t num_timeouts = 0;
+    //loop and recieve until the timeout
     while(true){
         usrp2_ctrl_data_t ctrl_data_in;
-        size_t len = udp_transport->recv(
-            boost::asio::buffer(&ctrl_data_in, sizeof(ctrl_data_in))
-        );
+        size_t len = udp_transport->recv(asio::buffer(&ctrl_data_in, sizeof(ctrl_data_in)));
         //std::cout << len << "\n";
-        if (len < sizeof(usrp2_ctrl_data_t)){
-            //sleep a little so we dont burn cpu
-            if (num_timeouts++ > 50) break;
-            boost::this_thread::sleep(boost::posix_time::milliseconds(1));
-        }else{
+        if (len >= sizeof(usrp2_ctrl_data_t)){
             //handle the received data
             switch(ntohl(ctrl_data_in.id)){
             case USRP2_CTRL_ID_THIS_IS_MY_IP_ADDR_DUDE:
@@ -61,12 +63,14 @@ uhd::device_addrs_t usrp2::discover(const device_addr_t &hint){
                 boost::asio::ip::address_v4 ip_addr(ntohl(ctrl_data_in.data.ip_addr));
                 device_addr_t new_addr;
                 new_addr["name"] = "USRP2";
-                new_addr["type"] = "usrp2";
+                new_addr["transport"] = "udp";
                 new_addr["addr"] = ip_addr.to_string();
                 usrp2_addrs.push_back(new_addr);
-                break;
+                //dont break here, it will exit the while loop
+                //just continue on to the next loop iteration
             }
         }
+        if (len == 0) break; //timeout
     }
 
     return usrp2_addrs;
@@ -75,16 +79,18 @@ uhd::device_addrs_t usrp2::discover(const device_addr_t &hint){
 /***********************************************************************
  * Make
  **********************************************************************/
-#define num2str(num) (boost::lexical_cast<std::string>(num))
+template <class T> std::string num2str(T num){
+    return boost::lexical_cast<std::string>(num);
+}
 
 device::sptr usrp2::make(const device_addr_t &device_addr){
     //create a control transport
-    transport::udp::sptr ctrl_transport = transport::udp::make(
+    udp_simple::sptr ctrl_transport = udp_simple::make_connected(
         device_addr["addr"], num2str(USRP2_UDP_CTRL_PORT)
     );
 
     //create a data transport
-    transport::udp::sptr data_transport = transport::udp::make(
+    udp_zero_copy::sptr data_transport = udp_zero_copy::make(
         device_addr["addr"], num2str(USRP2_UDP_DATA_PORT)
     );
 
@@ -98,8 +104,8 @@ device::sptr usrp2::make(const device_addr_t &device_addr){
  * Structors
  **********************************************************************/
 usrp2_impl::usrp2_impl(
-    transport::udp::sptr ctrl_transport,
-    transport::udp::sptr data_transport
+    udp_simple::sptr ctrl_transport,
+    udp_zero_copy::sptr data_transport
 ){
     _ctrl_transport = ctrl_transport;
     _data_transport = data_transport;
@@ -132,9 +138,8 @@ usrp2_impl::usrp2_impl(
     //init the tx and rx dboards (do last)
     dboard_init();
 
-    //send a small data packet so the usrp2 knows the udp source port
-    uint32_t zero_data = 0;
-    _data_transport->send(boost::asio::buffer(&zero_data, sizeof(zero_data)));
+    //init the send and recv io
+    io_init();
 
 }
 
@@ -160,24 +165,15 @@ usrp2_ctrl_data_t usrp2_impl::ctrl_send_and_recv(const usrp2_ctrl_data_t &out_da
     out_copy.seq = htonl(++_ctrl_seq_num);
     _ctrl_transport->send(boost::asio::buffer(&out_copy, sizeof(usrp2_ctrl_data_t)));
 
-    //loop and recieve until the time is up
-    size_t num_timeouts = 0;
+    //loop until we get the packet or timeout
     while(true){
         usrp2_ctrl_data_t in_data;
-        size_t len = _ctrl_transport->recv(
-            boost::asio::buffer(&in_data, sizeof(in_data))
-        );
-        if (len < sizeof(usrp2_ctrl_data_t)){
-            //sleep a little so we dont burn cpu
-            if (num_timeouts++ > 50) break;
-            boost::this_thread::sleep(boost::posix_time::milliseconds(1));
-        }else{
-            //handle the received data
-            if (ntohl(in_data.seq) == _ctrl_seq_num){
-                return in_data;
-            }
-            //didnt get seq, continue on...
+        size_t len = _ctrl_transport->recv(asio::buffer(&in_data, sizeof(in_data)));
+        if (len >= sizeof(usrp2_ctrl_data_t) and ntohl(in_data.seq) == _ctrl_seq_num){
+            return in_data;
         }
+        if (len == 0) break; //timeout
+        //didnt get seq or bad packet, continue looking...
     }
     throw std::runtime_error("usrp2 no control response");
 }
@@ -190,18 +186,28 @@ void usrp2_impl::get(const wax::obj &key_, wax::obj &val){
     boost::tie(key, name) = extract_named_prop(key_);
 
     //handle the get request conditioned on the key
-    switch(wax::cast<device_prop_t>(key)){
+    switch(key.as<device_prop_t>()){
     case DEVICE_PROP_NAME:
         val = std::string("usrp2 device");
         return;
 
     case DEVICE_PROP_MBOARD:
+        ASSERT_THROW(_mboards.has_key(name));
         val = _mboards[name].get_link();
         return;
 
     case DEVICE_PROP_MBOARD_NAMES:
         val = prop_names_t(_mboards.get_keys());
         return;
+
+    case DEVICE_PROP_MAX_RX_SAMPLES:
+        val = size_t(_max_rx_samples_per_packet);
+        return;
+
+    case DEVICE_PROP_MAX_TX_SAMPLES:
+        val = size_t(_max_tx_samples_per_packet);
+        return;
+
     }
 }
 
diff --git a/host/lib/usrp/usrp2/usrp2_impl.hpp b/host/lib/usrp/usrp2/usrp2_impl.hpp
index 9a4c42d42..fc713c2bf 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.hpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.hpp
@@ -22,7 +22,9 @@
 #include <boost/thread.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/function.hpp>
-#include <uhd/transport/udp.hpp>
+#include <uhd/transport/vrt.hpp>
+#include <uhd/transport/udp_simple.hpp>
+#include <uhd/transport/udp_zero_copy.hpp>
 #include <uhd/usrp/dboard_manager.hpp>
 #include "fw_common.h"
 
@@ -81,8 +83,8 @@ public:
      * \param data_transport the udp transport for data
      */
     usrp2_impl(
-        uhd::transport::udp::sptr ctrl_transport,
-        uhd::transport::udp::sptr data_transport
+        uhd::transport::udp_simple::sptr ctrl_transport,
+        uhd::transport::udp_zero_copy::sptr data_transport
     );
 
     ~usrp2_impl(void);
@@ -98,18 +100,32 @@ public:
     double get_master_clock_freq(void);
 
     //the io interface
-    size_t send(const boost::asio::const_buffer &, const uhd::metadata_t &, const std::string &);
-    size_t recv(const boost::asio::mutable_buffer &, uhd::metadata_t &, const std::string &);
+    size_t send(const boost::asio::const_buffer &, const uhd::tx_metadata_t &, const std::string &);
+    size_t recv(const boost::asio::mutable_buffer &, uhd::rx_metadata_t &, const std::string &);
 
 private:
     //the raw io interface (samples are in the usrp2 native format)
-    size_t send_raw(const boost::asio::const_buffer &, const uhd::metadata_t &);
-    size_t recv_raw(const boost::asio::mutable_buffer &, uhd::metadata_t &);
-    uhd::dict<uint32_t, size_t> _stream_id_to_packet_seq;
+    void recv_raw(uhd::rx_metadata_t &);
+    uhd::dict<uint32_t, size_t> _tx_stream_id_to_packet_seq;
+    uhd::dict<uint32_t, size_t> _rx_stream_id_to_packet_seq;
+    static const size_t _mtu = 1500; //FIXME we have no idea
+    static const size_t _hdrs = (2 + 14 + 20 + 8); //size of headers (pad, eth, ip, udp)
+    static const size_t _max_rx_samples_per_packet =
+        (_mtu - _hdrs)/sizeof(uint32_t) -
+        USRP2_HOST_RX_VRT_HEADER_WORDS32 -
+        USRP2_HOST_RX_VRT_TRAILER_WORDS32
+    ;
+    static const size_t _max_tx_samples_per_packet =
+        (_mtu - _hdrs)/sizeof(uint32_t) -
+        uhd::transport::vrt::max_header_words32
+    ;
+    uhd::transport::smart_buffer::sptr _rx_smart_buff;
+    boost::asio::const_buffer _rx_copy_buff;
+    void io_init(void);
 
     //udp transports for control and data
-    uhd::transport::udp::sptr _ctrl_transport;
-    uhd::transport::udp::sptr _data_transport;
+    uhd::transport::udp_simple::sptr _ctrl_transport;
+    uhd::transport::udp_zero_copy::sptr _data_transport;
 
     //private vars for dealing with send/recv control
     uint32_t _ctrl_seq_num;
@@ -119,6 +135,7 @@ private:
     std::string _pps_source, _pps_polarity, _ref_source;
     void init_clock_config(void);
     void update_clock_config(void);
+    void set_time_spec(const uhd::time_spec_t &time_spec, bool now);
 
     //mappings from clock config strings to over the wire enums
     uhd::dict<std::string, usrp2_pps_source_t>   _pps_source_dict;
diff --git a/host/lib/wax.cpp b/host/lib/wax.cpp
index c08398c50..0e2e82a3a 100644
--- a/host/lib/wax.cpp
+++ b/host/lib/wax.cpp
@@ -36,7 +36,11 @@ public:
     link_args_t(const wax::obj *obj_ptr) : _obj_ptr(obj_ptr){
         /* NOP */
     }
-    wax::obj & operator()(void){
+    wax::obj & operator()(void) const{
+        //recursively resolve link args to get at original pointer
+        if (_obj_ptr->type() == typeid(link_args_t)){
+            return _obj_ptr->as<link_args_t>()();
+        }
         return *const_cast<wax::obj *>(_obj_ptr);
     }
 private:
@@ -56,10 +60,10 @@ public:
     proxy_args_t(const wax::obj *obj_ptr, const wax::obj &key) : _key(key){
         _obj_link = obj_ptr->get_link();
     }
-    wax::obj & operator()(void){
-        return wax::cast<link_args_t>(_obj_link)();
+    wax::obj & operator()(void) const{
+        return _obj_link.as<link_args_t>()();
     }
-    const wax::obj & key(void){
+    const wax::obj & key(void) const{
         return _key;
     }
 private:
@@ -90,7 +94,7 @@ wax::obj wax::obj::operator[](const obj &key){
         obj val = resolve();
         //check if its a special link and call
         if (val.type() == typeid(link_args_t)){
-            return cast<link_args_t>(val)()[key];
+            return val.as<link_args_t>()()[key];
         }
         //unknown obj
         throw std::runtime_error("cannot use [] on non wax::obj link");
diff --git a/host/test/CMakeLists.txt b/host/test/CMakeLists.txt
index 234b6f92c..b1d5924c7 100644
--- a/host/test/CMakeLists.txt
+++ b/host/test/CMakeLists.txt
@@ -20,6 +20,7 @@ ADD_EXECUTABLE(main_test
     main_test.cpp
     addr_test.cpp
     gain_handler_test.cpp
+    vrt_test.cpp
     wax_test.cpp
 )
 
diff --git a/host/test/gain_handler_test.cpp b/host/test/gain_handler_test.cpp
index c81221aac..a4005c0de 100644
--- a/host/test/gain_handler_test.cpp
+++ b/host/test/gain_handler_test.cpp
@@ -17,33 +17,36 @@
 
 #include <boost/test/unit_test.hpp>
 #include <uhd/gain_handler.hpp>
+#include <uhd/props.hpp>
 #include <uhd/dict.hpp>
+#include <boost/bind.hpp>
 #include <iostream>
 
 using namespace uhd;
 
 enum prop_t{
-    PROP_GAIN,
-    PROP_GAIN_MIN,
-    PROP_GAIN_MAX,
-    PROP_GAIN_STEP,
+    PROP_GAIN_VALUE,
+    PROP_GAIN_RANGE,
     PROP_GAIN_NAMES
 };
 
 class gainful_obj : public wax::obj{
 public:
     gainful_obj(void){
-        _gain_handler = gain_handler::sptr(new gain_handler(
-            this, PROP_GAIN, PROP_GAIN_MIN, PROP_GAIN_MAX, PROP_GAIN_STEP, PROP_GAIN_NAMES
-        ));
-        _gains["g0"] = 0;
-        _gains["g1"] = 0;
-        _gains_min["g0"] = -10;
-        _gains_min["g1"] = 0;
-        _gains_max["g0"] = 0;
-        _gains_max["g1"] = 100;
-        _gains_step["g0"] = .1;
-        _gains_step["g1"] = 1.5;
+        //initialize gain props struct
+        gain_handler::props_t gain_props;
+        gain_props.value = PROP_GAIN_VALUE;
+        gain_props.range = PROP_GAIN_RANGE;
+        gain_props.names = PROP_GAIN_NAMES;
+        //make a new gain handler
+        _gain_handler = gain_handler::make(
+            this->get_link(), gain_props,
+            boost::bind(&gain_handler::is_equal<prop_t>, _1, _2)
+        );
+        _gain_values["g0"] = 0;
+        _gain_values["g1"] = 0;
+        _gain_ranges["g0"] = gain_range_t(-10, 0, .1);
+        _gain_ranges["g1"] = gain_range_t(0, 100, 1.5);
     }
 
     ~gainful_obj(void){}
@@ -56,25 +59,17 @@ private:
         boost::tie(key, name) = extract_named_prop(key_);
 
         //handle the get request conditioned on the key
-        switch(wax::cast<prop_t>(key)){
-        case PROP_GAIN:
-            val = _gains[name];
+        switch(key.as<prop_t>()){
+        case PROP_GAIN_VALUE:
+            val = _gain_values[name];
             return;
 
-        case PROP_GAIN_MIN:
-            val = _gains_min[name];
-            return;
-
-        case PROP_GAIN_MAX:
-            val = _gains_max[name];
-            return;
-
-        case PROP_GAIN_STEP:
-            val = _gains_step[name];
+        case PROP_GAIN_RANGE:
+            val = _gain_ranges[name];
             return;
 
         case PROP_GAIN_NAMES:
-            val = prop_names_t(_gains.get_keys());
+            val = _gain_values.get_keys();
             return;
         }
     }
@@ -86,24 +81,20 @@ private:
         boost::tie(key, name) = extract_named_prop(key_);
 
         //handle the get request conditioned on the key
-        switch(wax::cast<prop_t>(key)){
-        case PROP_GAIN:
-            _gains[name] = wax::cast<gain_t>(val);
+        switch(key.as<prop_t>()){
+        case PROP_GAIN_VALUE:
+            _gain_values[name] = val.as<gain_t>();
             return;
 
-        case PROP_GAIN_MIN:
-        case PROP_GAIN_MAX:
-        case PROP_GAIN_STEP:
+        case PROP_GAIN_RANGE:
         case PROP_GAIN_NAMES:
             throw std::runtime_error("cannot set this property");
         }
     }
 
     gain_handler::sptr _gain_handler;
-    uhd::dict<std::string, gain_t> _gains;
-    uhd::dict<std::string, gain_t> _gains_min;
-    uhd::dict<std::string, gain_t> _gains_max;
-    uhd::dict<std::string, gain_t> _gains_step;
+    uhd::dict<std::string, gain_t> _gain_values;
+    uhd::dict<std::string, gain_range_t> _gain_ranges;
 
 };
 
@@ -112,17 +103,20 @@ BOOST_AUTO_TEST_CASE(test_gain_handler){
     gainful_obj go0;
 
     BOOST_CHECK_THROW(
-        wax::cast<gain_t>(go0[named_prop_t(PROP_GAIN, "fail")]),
-        std::invalid_argument
+        go0[named_prop_t(PROP_GAIN_VALUE, "fail")].as<gain_t>(),
+        std::exception
     );
 
     std::cout << "verifying the overall min, max, step" << std::endl;
-    BOOST_CHECK_EQUAL(wax::cast<gain_t>(go0[PROP_GAIN_MIN]), gain_t(-10));
-    BOOST_CHECK_EQUAL(wax::cast<gain_t>(go0[PROP_GAIN_MAX]), gain_t(100));
-    BOOST_CHECK_EQUAL(wax::cast<gain_t>(go0[PROP_GAIN_STEP]), gain_t(1.5));
+    gain_t gain_min, gain_max, gain_step;
+    boost::tie(gain_min, gain_max, gain_step) = \
+        go0[PROP_GAIN_RANGE].as<gain_range_t>();
+    BOOST_CHECK_EQUAL(gain_min, gain_t(-10));
+    BOOST_CHECK_EQUAL(gain_max, gain_t(100));
+    BOOST_CHECK_EQUAL(gain_step, gain_t(1.5));
 
     std::cout << "verifying the overall gain" << std::endl;
-    go0[named_prop_t(PROP_GAIN, "g0")] = gain_t(-5);
-    go0[named_prop_t(PROP_GAIN, "g1")] = gain_t(30);
-    BOOST_CHECK_EQUAL(wax::cast<gain_t>(go0[PROP_GAIN]), gain_t(25));
+    go0[named_prop_t(PROP_GAIN_VALUE, "g0")] = gain_t(-5);
+    go0[named_prop_t(PROP_GAIN_VALUE, "g1")] = gain_t(30);
+    BOOST_CHECK_EQUAL(go0[PROP_GAIN_VALUE].as<gain_t>(), gain_t(25));
 }
diff --git a/host/test/vrt_test.cpp b/host/test/vrt_test.cpp
new file mode 100644
index 000000000..d80908c74
--- /dev/null
+++ b/host/test/vrt_test.cpp
@@ -0,0 +1,100 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <boost/test/unit_test.hpp>
+#include <uhd/transport/vrt.hpp>
+
+using namespace uhd::transport;
+
+static void pack_and_unpack(
+    const uhd::tx_metadata_t &metadata,
+    size_t num_payload_words32,
+    size_t packet_count
+){
+    uint32_t header_buff[vrt::max_header_words32];
+    size_t num_header_words32;
+    size_t num_packet_words32;
+
+    //pack metadata into a vrt header
+    vrt::pack(
+        metadata,            //input
+        header_buff,         //output
+        num_header_words32,  //output
+        num_payload_words32, //input
+        num_packet_words32,  //output
+        packet_count         //input
+    );
+
+    uhd::rx_metadata_t metadata_out;
+    size_t num_header_words32_out;
+    size_t num_payload_words32_out;
+    size_t packet_count_out;
+
+    //unpack the vrt header back into metadata
+    vrt::unpack(
+        metadata_out,            //output
+        header_buff,             //input
+        num_header_words32_out,  //output
+        num_payload_words32_out, //output
+        num_packet_words32,      //input
+        packet_count_out         //output
+    );
+
+    //check the the unpacked metadata is the same
+    BOOST_CHECK_EQUAL(packet_count, packet_count_out);
+    BOOST_CHECK_EQUAL(num_header_words32, num_header_words32_out);
+    BOOST_CHECK_EQUAL(num_payload_words32, num_payload_words32_out);
+    BOOST_CHECK_EQUAL(metadata.has_stream_id, metadata_out.has_stream_id);
+    if (metadata.has_stream_id and metadata_out.has_stream_id){
+        BOOST_CHECK_EQUAL(metadata.stream_id, metadata_out.stream_id);
+    }
+    BOOST_CHECK_EQUAL(metadata.has_time_spec, metadata_out.has_time_spec);
+    if (metadata.has_time_spec and metadata_out.has_time_spec){
+        BOOST_CHECK_EQUAL(metadata.time_spec.secs, metadata_out.time_spec.secs);
+        BOOST_CHECK_EQUAL(metadata.time_spec.ticks, metadata_out.time_spec.ticks);
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_with_none){
+    uhd::tx_metadata_t metadata;
+    pack_and_unpack(metadata, 300, 1);
+}
+
+BOOST_AUTO_TEST_CASE(test_with_sid){
+    uhd::tx_metadata_t metadata;
+    metadata.has_stream_id = true;
+    metadata.stream_id = 6;
+    pack_and_unpack(metadata, 400, 2);
+}
+
+BOOST_AUTO_TEST_CASE(test_with_time_spec){
+    uhd::tx_metadata_t metadata;
+    metadata.has_time_spec = true;
+    metadata.time_spec.secs = 7;
+    metadata.time_spec.ticks = 2000;
+    pack_and_unpack(metadata, 500, 3);
+}
+
+BOOST_AUTO_TEST_CASE(test_with_sid_and_time_spec){
+    uhd::tx_metadata_t metadata;
+    metadata.has_stream_id = true;
+    metadata.stream_id = 2;
+    metadata.has_time_spec = true;
+    metadata.time_spec.secs = 5;
+    metadata.time_spec.ticks = 1000;
+    pack_and_unpack(metadata, 600, 4);
+}
diff --git a/host/test/wax_test.cpp b/host/test/wax_test.cpp
index e5e1adc25..b793b2690 100644
--- a/host/test/wax_test.cpp
+++ b/host/test/wax_test.cpp
@@ -17,14 +17,15 @@
 
 #include <boost/test/unit_test.hpp>
 #include <uhd/wax.hpp>
+#include <iostream>
 
 enum opt_a_t{OPTION_A_0, OPTION_A_1};
 enum opt_b_t{OPTION_B_0, OPTION_B_1};
 
 BOOST_AUTO_TEST_CASE(test_enums){
     wax::obj opta = OPTION_A_0;
-    BOOST_CHECK_THROW(wax::cast<opt_b_t>(opta), wax::bad_cast);
-    BOOST_CHECK_EQUAL(wax::cast<opt_a_t>(opta), OPTION_A_0);
+    BOOST_CHECK_THROW(opta.as<opt_b_t>(), wax::bad_cast);
+    BOOST_CHECK_EQUAL(opta.as<opt_a_t>(), OPTION_A_0);
 }
 
 /***********************************************************************
@@ -48,14 +49,14 @@ public:
     }
     void get(const wax::obj &key, wax::obj &value){
         if (d_subs.size() == 0){
-            value = d_nums[wax::cast<size_t>(key)];
+            value = d_nums[key.as<size_t>()];
         }else{
-            value = d_subs[wax::cast<size_t>(key)].get_link();
+            value = d_subs[key.as<size_t>()].get_link();
         }
     }
     void set(const wax::obj &key, const wax::obj &value){
         if (d_subs.size() == 0){
-            d_nums[wax::cast<size_t>(key)] = wax::cast<float>(value);
+            d_nums[key.as<size_t>()] = value.as<float>();
         }else{
             throw std::runtime_error("cant set to a wax demo with sub demos");
         }
@@ -81,7 +82,7 @@ BOOST_AUTO_TEST_CASE(test_set_get){
                 float val = i * j * k + i + j + k;
                 //std::cout << i << " " << j << " " << k << std::endl;
                 wd[i][j][k] = val;
-                BOOST_CHECK_EQUAL(val, wax::cast<float>(wd[i][j][k]));
+                BOOST_CHECK_EQUAL(val, wd[i][j][k].as<float>());
             }
         }
     }
@@ -94,5 +95,5 @@ BOOST_AUTO_TEST_CASE(test_proxy){
 
     std::cout << "assign proxy" << std::endl;
     wax::obj a = p[size_t(0)];
-    BOOST_CHECK_EQUAL(wax::cast<float>(a), float(5));
+    BOOST_CHECK_EQUAL(a.as<float>(), float(5));
 }