diff --git a/tests/test_api.py b/tests/test_api.py
index 7e1bf04..3cc3df5 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -155,6 +155,25 @@ def test_frame_received(api, monkeypatch):
         my_handler.reset_mock()
 
 
+def test_frame_received_no_handler(api, monkeypatch):
+    monkeypatch.setattr(t, 'deserialize', mock.MagicMock(
+        return_value=(b'deserialized data', b'')))
+    my_handler = mock.MagicMock()
+    cmd = 'no_handler'
+    cmd_id = 0x00
+    xbee_api.COMMANDS[cmd] = (cmd_id, (), None)
+    api._commands_by_id[cmd_id] = cmd
+
+    cmd_opts = xbee_api.COMMANDS[cmd]
+    cmd_id = cmd_opts[0]
+    payload = b'\x01\x02\x03\x04'
+    data = cmd_id.to_bytes(1, 'big') + payload
+    api.frame_received(data)
+    assert t.deserialize.call_count == 1
+    assert t.deserialize.call_args[0][0] == payload
+    assert my_handler.call_count == 0
+
+
 def _handle_at_response(api, tsn, status, at_response=b''):
     data = (tsn, 'AI'.encode('ascii'), status, at_response)
     response = asyncio.Future()
@@ -346,3 +365,9 @@ def test_set_application(api):
 
 def test_handle_route_record_indicator(api):
     api._handle_route_record_indicator(mock.sentinel.ri)
+
+
+def test_handle_many_to_one_rri(api):
+    ieee = t.EUI64([t.uint8_t(a) for a in range(0, 8)])
+    nwk = 0x1234
+    api._handle_many_to_one_rri([ieee, nwk, 0])
diff --git a/tests/test_types.py b/tests/test_types.py
index c3c6dac..48cdcd7 100644
--- a/tests/test_types.py
+++ b/tests/test_types.py
@@ -71,3 +71,10 @@ class undEnum(t.uint8_t, t.UndefinedEnum):
 
     with pytest.raises(ValueError):
         undEnum(0xEE)
+
+
+def test_nwk():
+    nwk = t.NWK(0x1234)
+
+    assert str(nwk) == '0x1234'
+    assert repr(nwk) == '0x1234'
diff --git a/zigpy_xbee/api.py b/zigpy_xbee/api.py
index 129e757..dbce120 100644
--- a/zigpy_xbee/api.py
+++ b/zigpy_xbee/api.py
@@ -1,4 +1,5 @@
 import asyncio
+import binascii
 import enum
 import logging
 
@@ -32,21 +33,21 @@ class ModemStatus(t.uint8_t, t.UndefinedEnum):
     'queued_at': (0x09, (t.uint8_t, t.ATCommand, t.Bytes), 0x88),
     'remote_at': (0x17, (), None),
     'tx': (0x10, (), None),
-    'tx_explicit': (0x11, (t.uint8_t, t.EUI64, t.uint16_t, t.uint8_t, t.uint8_t, t.uint16_t, t.uint16_t, t.uint8_t, t.uint8_t, t.Bytes), None),
-    'create_source_route': (0x21, (), None),
+    'tx_explicit': (0x11, (t.uint8_t, t.EUI64, t.NWK, t.uint8_t, t.uint8_t, t.uint16_t, t.uint16_t, t.uint8_t, t.uint8_t, t.Bytes), None),
+    'create_source_route': (0x21, (t.uint8_t, t.EUI64, t.NWK, t.uint8_t, LVList(t.NWK)), None),
     'register_joining_device': (0x24, (), None),
 
     'at_response': (0x88, (t.uint8_t, t.ATCommand, t.uint8_t, t.Bytes), None),
     'modem_status': (0x8A, (ModemStatus, ), None),
-    'tx_status': (0x8B, (t.uint8_t, t.uint16_t, t.uint8_t, t.uint8_t, t.uint8_t), None),
+    'tx_status': (0x8B, (t.uint8_t, t.NWK, t.uint8_t, t.uint8_t, t.uint8_t), None),
     'route_information': (0x8D, (), None),
     'rx': (0x90, (), None),
-    'explicit_rx_indicator': (0x91, (t.EUI64, t.uint16_t, t.uint8_t, t.uint8_t, t.uint16_t, t.uint16_t, t.uint8_t, t.Bytes), None),
+    'explicit_rx_indicator': (0x91, (t.EUI64, t.NWK, t.uint8_t, t.uint8_t, t.uint16_t, t.uint16_t, t.uint8_t, t.Bytes), None),
     'rx_io_data_long_addr': (0x92, (), None),
     'remote_at_response': (0x97, (), None),
     'extended_status': (0x98, (), None),
-    'route_record_indicator': (0xA1, (t.EUI64, t.uint16_t, t.uint8_t, LVList(t.uint16_t)), None),
-    'many_to_one_rri': (0xA3, (), None),
+    'route_record_indicator': (0xA1, (t.EUI64, t.NWK, t.uint8_t, LVList(t.NWK)), None),
+    'many_to_one_rri': (0xA3, (t.EUI64, t.NWK, t.uint8_t), None),
     'node_id_indicator': (0x95, (), None),
 
 }
@@ -261,7 +262,11 @@ def frame_received(self, data):
         command = self._commands_by_id[data[0]]
         LOGGER.debug("Frame received: %s", command)
         data, rest = t.deserialize(data[1:], COMMANDS[command][1])
-        getattr(self, '_handle_%s' % (command, ))(data)
+        try:
+            getattr(self, '_handle_%s' % (command, ))(data)
+        except AttributeError:
+            LOGGER.error("No '%s' handler. Data: %s", command,
+                         binascii.hexlify(data))
 
     def _handle_at_response(self, data):
         fut, = self._awaiting.pop(data[0])
@@ -283,6 +288,9 @@ def _handle_at_response(self, data):
         response, remains = response_type.deserialize(data[3])
         fut.set_result(response)
 
+    def _handle_many_to_one_rri(self, data):
+        LOGGER.debug("_handle_many_to_one_rri: %s", data)
+
     def _handle_modem_status(self, data):
         LOGGER.debug("Handle modem status frame: %s", data)
         status = data[0]
diff --git a/zigpy_xbee/types.py b/zigpy_xbee/types.py
index 7b7a868..be3ac13 100644
--- a/zigpy_xbee/types.py
+++ b/zigpy_xbee/types.py
@@ -147,3 +147,11 @@ def __call__(cls, value=None, *args, **kwargs):
 
 class UndefinedEnum(enum.Enum, metaclass=UndefinedEnumMeta):
     pass
+
+
+class NWK(uint16_t):
+    def __repr__(self):
+        return '0x{:04x}'.format(self)
+
+    def __str__(self):
+        return '0x{:04x}'.format(self)