I am experiencing dropped frames at the beginning of transmission between an XB24-B module + XBIB USB dev board combo and a ConnectPort X2. The XB24-B is running ZNET 2.5 Router/End Device AT firmware with default params. The X2 is running Firmware 2.6.4 (Version 82001596_A 09/27/2007). Here is the procedure I use to replicate the problem.
STEP 1: Upload the following python program to the X2
[pre]
include the sockets module into the namespace:
from socket import *
import sys
Create the socket, datagram mode, proprietary transport:
sd = socket(AF_ZIGBEE, SOCK_DGRAM, ZBS_PROT_TRANSPORT)
Bind to endpoint 0xe8 (234):
sd.bind((“”, 0xe8, 0, 0))
while 1:
# Block until a single frame is received, up to 72 bytes:
payload, src_addr = sd.recvfrom(72)
print
print "src_addr: ", src_addr
print "len(payload): %d" % len(payload)
for index, byte in enumerate(payload):
print "payload[%d] = '%s' (%s, %d)" % (index, byte, hex(ord(byte)), ord(byte))
if byte == 'z':
sys.exit()
[/pre]
STEP 2: Reboot the X2 and do a network discovery via the web interface. In the web interface, both the coordinator and the router (modem) appear.
STEP 3: Start X-CTU, test/query the modem, and go to the terminal interface.
STEP 4: Telnet to the X2 and start the above python program (#1 in the attached screen capture).
STEP 5: In the X-CTU terminal window, starting typing the alphabet slowly (#2 in the screen capture).
STEP 6: Notice in the telnet session that characters ‘a’, ‘b’ and ‘c’ didn’t arrive (#3 in the screen capture). This is verified by looking at the mesh network counters in the web interface (#4 in the screen capture).
So the obvious question then, why don’t the first few frames go through? Shouldn’t this scare the hell out of me? 
As always, any help is much appreciated.
Cheers,
Darran.