If you take a raw capture on the Kamailio box:
tcpdump -i any -A -s 0 -n udp port 8002 and host PUBLIC_IP
Does it not show Kamailio attempting to relay it there?
--
Alex Balashov | Principal | Evariste Systems LLC
303 Perimeter Center North, Suite 300
Atlanta, GA 30346
United States
Tel: +1-800-250-5920 (toll-free) / +1-678-954-0671 (direct)
Web:
http://www.evaristesys.com/,
http://www.csrpswitch.com/