[Asterisk-Users] Problem with NAT!!!

[Conrad Wood]

On Fri, 2006-03-03 at 10:45 +0100, serge messa wrote:
> Hi all
> 
>    I'm a newbie in asterisk.I install asterisk server
> successfully. I configure this server to traverse NAT.
> Using Xlite clients, i make a call between 2 local
> networks through Internet.Asterisk  server is
> installed on a host with public IP. client A (in the
> LAn A) and client B (in the LAN B) are registered.
> When i make a call from the LAN A to the LAn B,
> everything goes well.But, when i try to make a call
> from the Lan B to the Lan A, the xlite client B,

How do connect Lan A and Lan B to the internet?
Do they both have a public static IP or are they dynamically assigned?
Are they both the same routers?
It might be far off but here's a couple of possible reasons:
a) either one LAN keeps changing it's public IP (or just bad timing that
the IP of Lan A changed when you tried to place your call to it)
b) Either Router (a or b) might not allow the relevant packets through
to xlite (or to the internet)
Can you give more details on your configuration?
Can you provide asterisk logs?

Conrad