diff --git a/const.py b/const.py
index 79d7010..db16983 100644
--- a/const.py
+++ b/const.py
@@ -2,7 +2,7 @@
 Constants used across package
 """
 
-from enum import Enum
+from enum import IntEnum
 
 MINIMUM_BLINK_RATE = 20
 
@@ -15,9 +15,36 @@
 
 PACKETHEADER_LINKBIT = 0x80
 
-GatewayCmdSendToSerial = 0x30
+class GatewayCmd(IntEnum):
+    KEEP_ALIVE = 0x10
+    SET_DATE_TIME = 0x20
+    GET_DATE_TIME = 0x22
+    SET_SCHEDULE = 0x28
+    GET_SCHEDULE = 0x2a
+    SEND_TO_SERIAL = 0x30
+    FILE_WRITE_OPEN = 0x50
+    FILE_WRITE = 0x52
+    FILE_WRITE_SIZE = 0x54
+    FILE_WRITE_CLOSE = 0x56
+    FILE_READ_OPEN = 0x60
+    FILE_READ = 0x62
+    FILE_READ_SIZE = 0x64
+    FILE_READ_CLOSE = 0x66
+    FILE_READ_DELETE = 0x70
+    DIR_LISTING = 0x80
+    START_PULSE_MODE = 0x90
+    EXIT_PULSE_MODE = 0x92
+    SERIAL_MESSAGE = 0xe0
+    DEVICE_STATE_CHANGE = 0xe2
+    DISCONNECT = 0xf0
+    PULSE_MODE_APP_CONNECTED = 0xf2
+    CMD_NAK = 0xff
 
-class UpbTransmission(Enum):
+    @classmethod
+    def has_value(cls, value):
+        return value in cls._value2member_map_
+
+class UpbTransmission(IntEnum):
     UPB_MESSAGE = 0x55 # U
     UPB_PIM_ACCEPT = 0x41 # A
     UPB_PIM_BUSY = 0x42 # B
@@ -26,7 +53,7 @@ class UpbTransmission(Enum):
     UPB_TRANSMISSION_ACK = 0x4b # K
     UPB_TRANSMISSION_NAK = 0x4e # N
 
-class UpbMessage(Enum):
+class UpbMessage(IntEnum):
     UPB_MESSAGE_PIMREPORT = 0x50 # P
     UPB_MESSAGE_START = 0x58 # X
     UPB_MESSAGE_SYNC = 0x52 # R
@@ -54,12 +81,12 @@ def is_message_data(cls, value):
         return False
 
 
-class PimCommand(Enum):
+class PimCommand(IntEnum):
     UPB_NETWORK_TRANSMIT = 0x14
     UPB_PIM_READ = 0x12
     UPB_PIM_WRITE = 0x17
 
-class UpbReg(Enum):
+class UpbReg(IntEnum):
     UPB_REG_NETWORKID = 0x00
     UPB_REG_MODULEID = 0x01
     UPB_REG_PASSWORD = 0x02
@@ -79,7 +106,7 @@ class UpbReg(Enum):
     UPB_REG_NOISEFLOOR = 0xfa
     UPB_REG_NOISECOUNTS = 0xfb
 
-class UpbDeviceId(Enum):
+class UpbDeviceId(IntEnum):
     BROADCAST_DEVICEID = 0x00
     RESERVED1_DEVICEID = 0xfb
     RESERVED2_DEVICEID = 0xfc
@@ -91,19 +118,19 @@ class UpbDeviceId(Enum):
     def has_value(cls, value):
         return value in cls._value2member_map_
 
-class UpbReqAck(Enum):
+class UpbReqAck(IntEnum):
     REQ_ACKDEFAULT = 0x00
     REQ_ACKMESSAGE = 0x01
     REQ_NOACK = 0x02
     REQ_ACKNOREQUEUEONNAK = 0x04
 
-class UpbReqRepeater(Enum):
+class UpbReqRepeater(IntEnum):
     REP_NONREPEATER = 0x00
     REP_LOWREPEAT = 0x01
     REP_MEDIUMREPEAT = 0x02
     REP_HIGHREPEAT = 0x03
 
-class MdidSet(Enum):
+class MdidSet(IntEnum):
     MDID_CORE_COMMANDS = 0x00
     MDID_DEVICE_CONTROL_COMMANDS = 0x20
     MDID_RESERVED_COMMAND_SET1 = 0x40
@@ -113,7 +140,7 @@ class MdidSet(Enum):
     MDID_RESERVED_REPORT_SET2 = 0xc0
     MDID_EXTENDED_MESSAGE_SET = 0xe0
 
-class MdidCoreCmd(Enum):
+class MdidCoreCmd(IntEnum):
     MDID_CORE_COMMAND_NULL = 0x00
     MDID_CORE_COMMAND_WRITEENABLE = 0x01
     MDID_CORE_COMMAND_WRITEPROTECT = 0x02
@@ -133,7 +160,7 @@ class MdidCoreCmd(Enum):
     MDID_CORE_COMMAND_GETREGISTERVALUES = 0x10
     MDID_CORE_COMMAND_SETREGISTERVALUES = 0x11
 
-class MdidDeviceControlCmd(Enum):
+class MdidDeviceControlCmd(IntEnum):
     MDID_DEVICE_CONTROL_COMMAND_ACTIVATELINK = 0x00
     MDID_DEVICE_CONTROL_COMMAND_DEACTIVATELINK = 0x01
     MDID_DEVICE_CONTROL_COMMAND_GOTO = 0x02
@@ -143,7 +170,7 @@ class MdidDeviceControlCmd(Enum):
     MDID_DEVICE_CONTROL_COMMAND_REPORTSTATE = 0x10
     MDID_DEVICE_CONTROL_COMMAND_STORESTATE = 0x11
 
-class MdidCoreReport(Enum):
+class MdidCoreReport(IntEnum):
     MDID_DEVICE_CORE_REPORT_SETUPTIME = 0x05
     MDID_DEVICE_CORE_REPORT_DEVICESTATE = 0x06
     MDID_DEVICE_CORE_REPORT_DEVICESTATUS = 0x07
diff --git a/proxy.py b/proxy.py
index 10100b8..81a4968 100644
--- a/proxy.py
+++ b/proxy.py
@@ -3,11 +3,12 @@
 import hmac
 from pprint import pprint, pformat
 from binascii import unhexlify
+from struct import unpack
 
 from const import PimCommand, UpbMessage, UpbDeviceId, UpbTransmission, UpbReqAck, UpbReqRepeater, \
-MdidSet, MdidCoreCmd, MdidDeviceControlCmd, MdidCoreReport, GatewayCmdSendToSerial, \
+MdidSet, MdidCoreCmd, MdidDeviceControlCmd, MdidCoreReport, GatewayCmd, \
 UPB_MESSAGE_TYPE, UPB_MESSAGE_PIMREPORT_TYPE, INITIAL_PIM_REG_QUERY_BASE, PACKETHEADER_LINKBIT, PULSE_REPORT_BYTES
-from util import cksum
+from util import cksum, hexdump
 
 class PIM(asyncio.Protocol):
 
@@ -83,8 +84,7 @@ def process_packet(self, packet):
         pprint(response)
 
     def nt_line_received(self, line):
-        print(f'pim null terminated line: {line}')
-        self.wrapped = True
+        print(f'pim null terminated line: {line}, hex: {hexdump(line)}')
         errors = {
             'MAX CONNECTIONS REACHED',
             'PULSE MODE ACTIVE',
@@ -98,6 +98,7 @@ def nt_line_received(self, line):
             elif result == b'AUTH SUCCEEDED':
                 print("auth succeded")
                 self.initial = False
+                self.wrapped = True
             else:
                 print(f"unexpected auth result: {result}")
         elif self.initial:
@@ -235,17 +236,39 @@ def line_received(self, line):
 
     def data_received(self, data):
         self.buffer += data
-        print(f'pim buffer: {self.buffer}')
-        while b'\x00' in self.buffer:
-            line, self.buffer = self.buffer.split(b'\x00', 1)
-            if len(line) >= 1:
-                self.nt_line_received(line)
-        while b'\r' in self.buffer and not self.wrapped:
-            line, self.buffer = self.buffer.split(b'\r', 1)
-            if len(line) > 1:
-                self.line_received(line)
+        #print(f'pim buffer: {self.buffer}, hex: {hexdump(self.buffer)}')
         if self.server_transport:
             self.server_transport.write(data)
+        if self.wrapped:
+            while len(self.buffer) > 0 and GatewayCmd.has_value(self.buffer[0]-1):
+                if len(self.buffer) >= 8:
+                    rcCommand = self.buffer[1]
+                    assert(rcCommand == 0x00)
+                    length = unpack('>H', self.buffer[6:8])[0]
+                    #print(f"pim length: {length}")
+                    if len(self.buffer) >= length + 9:
+                        cmd = GatewayCmd(self.buffer[0]-1)
+                        #print(f"pim cmd: {cmd.name}")
+                        if cmd == GatewayCmd.SEND_TO_SERIAL:
+                            line = self.buffer[8:length+7]
+                            self.buffer = self.buffer[length+10:]
+                            #print(f"pim gateway response: {line}, hex: {hexdump(line)} length: {length}")
+                            self.line_received(line)
+                        elif cmd == GatewayCmd.KEEP_ALIVE:
+                            self.buffer = self.buffer[length+4:]
+                    else:
+                        return
+                else:
+                    return
+        else:
+            while b'\x00' in self.buffer:
+                line, self.buffer = self.buffer.split(b'\x00', 1)
+                if len(line) >= 1:
+                    self.nt_line_received(line)
+            while b'\r' in self.buffer and not self.wrapped:
+                line, self.buffer = self.buffer.split(b'\r', 1)
+                if len(line) > 1:
+                    self.line_received(line)
 
     def connection_lost(self, *args):
         print("pim connection lost")
@@ -274,7 +297,7 @@ def send_data(self, data):
         self.client.transport.write(data)
 
     def nt_line_received(self, line):
-        print(f'upstart null terminated line: {line}')
+        print(f'upstart null terminated line: {line}, hex: {hexdump(line)}')
         if self.initial:
             if self.client.pim_info.get('auth', None) == b'AUTH REQUIRED' and \
                 self.client.challenge is not None and self.client.authenticated is not True:
@@ -299,14 +322,9 @@ def nt_line_received(self, line):
                 }
                 self.client.protocol = protocol
             print(f'self.client_info:\n{pformat(self.client_info)}')
-        else:
-            if line[0] == GatewayCmdSendToSerial:
-                length_hi = line[1]
-                length_lo = line[2]
-                print(f"gateway to serial line: {line}, length_hi: {length_hi}, length_lo: {length_lo}")
 
     def line_received(self, line):
-        print(f'upstart line: {line}')
+        #print(f'upstart line: {line}')
         command = PimCommand(line[0])
         data = unhexlify(line[1:-2])
         crc = int(line[-2:], 16)
@@ -365,16 +383,36 @@ def line_received(self, line):
 
     def data_received(self, data):
         self.buffer += data
-        print(f'buffer: {self.buffer}')
-        while b'\x00' in self.buffer:
-            line, self.buffer = self.buffer.split(b'\x00', 1)
-            if len(line) > 0:
-                self.nt_line_received(line)
-        while b'\r' in self.buffer and not self.client.wrapped:
-            line, self.buffer = self.buffer.split(b'\r', 1)
-            if len(line) >= 1:
-                self.line_received(line)
+        #print(f'upstart buffer: {self.buffer}, hex: {hexdump(self.buffer)}')
         self.send_data(data)
+        if self.client.wrapped:
+            while len(self.buffer) > 0 and GatewayCmd.has_value(self.buffer[0]):
+                if len(self.buffer) >= 4:
+                    length = unpack('>H', self.buffer[1:3])[0]
+                    if len(self.buffer) > length + 4:
+                        #print(f"length: {length}")
+                        cmd = GatewayCmd(self.buffer[0])
+                        #print(f"cmd: {cmd.name}")
+                        if cmd == GatewayCmd.SEND_TO_SERIAL:
+                            line = self.buffer[3:length+2]
+                            self.buffer = self.buffer[length+4:]
+                            #print(f"gateway to serial line: {line}, hex: {hexdump(line)} length: {length}")
+                            self.line_received(line)
+                        elif cmd == GatewayCmd.KEEP_ALIVE:
+                            self.buffer = self.buffer[length+4:]
+                    else:
+                        return
+                else:
+                    return
+        else:
+            while b'\x00' in self.buffer:
+                line, self.buffer = self.buffer.split(b'\x00', 1)
+                if len(line) > 0:
+                    self.nt_line_received(line)
+            while b'\r' in self.buffer and not self.client.wrapped:
+                line, self.buffer = self.buffer.split(b'\r', 1)
+                if len(line) >= 1:
+                    self.line_received(line)
 
     def connection_lost(self, *args):
         print("upstart connection lost")
diff --git a/util.py b/util.py
index ee7f53f..c9b1862 100644
--- a/util.py
+++ b/util.py
@@ -4,3 +4,12 @@
 def cksum(data):
 	return (256 - reduce(lambda x, y: x + y, data)) % 256
 
+def hexdump(data, length=None, sep=':'):
+    if length is not None:
+        lines = ""
+        for seq in range(0, len(data), 16):
+            line = data[seq: seq + 16]
+            lines += sep.join("{:02x}".format(c) for c in line) + "\n"
+    else:
+        lines = sep.join("{:02x}".format(c) for c in data)
+    return lines