Hello.

For my first post, i hope you could help me

Well, here my network :

- Firewall ubuntu - Kernell 2.6.24 - Ubuntu 8.04
2 network cards :
eth0 : public adress (194.2.X.Y)
eth1: local network (172.16.0.1)

- I've got a polycom Vx6000 visio-conferencing camera with 172.16.0.2 adress.

To allow incoming call from Internet to my polycom cam, i set this rules :

-
Code:
A PREROUTING -d 194.2.X.Y/32 -i eth0 -p tcp -m tcp --dport 1720 --tcp-flags SYN,RST,ACK SYN -j DNAT --to-destination 172.16.0.2 
-A PREROUTING -d 194.2.X.Y/32 -i eth0 -p udp -m udp --dport 1720 -j DNAT --to-destination 172.16.0.2 
-A PREROUTING -d 194.2.X.Y/32 -i eth0 -p tcp -m tcp --dport 3230:3235 --tcp-flags SYN,RST,ACK SYN -j DNAT --to-destination 172.16.0.2 
-A PREROUTING -d 194.2.X.Y/32 -i eth0 -p udp -m udp --dport 3230:3253 -j DNAT --to-destination 172.16.0.2
With tcpdump, i can see connexion on this ports.
I can receive calls, i can call others Internet Visio-Conferencing but i often, really often disconnect, or sometimes i've got no sound, another no video, sometimes both few minutes and then sound cut off....

Concerning H323 protocols, i've got this two modules in my Kernel :

Code:
root@fire:~# lsmod | grep h323
nf_nat_h323             8576  0 
nf_conntrack_h323      51164  1 nf_nat_h323
ipv6                  274084  31 nf_conntrack_h323
nf_nat                 20396  5 nf_nat_h323,ipt_REDIRECT,nf_nat_tftp,nf_nat_ftp,iptable_nat
nf_conntrack           66880  10 nf_nat_h323,nf_conntrack_h323,xt_state,nf_nat_tftp,nf_conntrack_tftp,nf_nat_ftp,nf_conntrack_ftp,iptable_nat,nf_nat,nf_conntrack_ipv4
root@fire:~#
Can you help me to solve this problem ? How can i see what the module is doing ? if he really receive h323 things, ...

Thanks all.

PS : Sorry for my english