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[ben4asterisk at yahoo.com]

Hello ppl,
This is an Asterisk behind a NAT issue.
I know, this issue has been beaten around to death on the lists, but somehow I haven't been able to find a solution, yet.

My set up :
Asterisk behind a NAT. The Asterisk has a dedicated public IP allocated on the NAT. Rest all peers (esp 3rd party SIP gateways) are on public.

So, I tried to set externip to the allocated external(public) IP.
But unfortunately * doesn't really send this IP in its SIP/SDP messages.
Only when I add localnet, does it send the extern IP in the SIP/ SDP messages.
But, the responses being received from my SIP gateway are somehow not recognized (i.e. as a response I think) and retransmissions of the initial INVITE occur. Through this I do get 180 adn 200 responses from my SIP gateway for the initial INVITE. After sometime I start getting '482 Loop Detected' from the SIP gateway.

Am attaching the SIP message flow for this.
externip=aaa.bbb.ccc.ddd
localnet=10.0.0.177/255.255.252.0

SIP gateway : mmm.nnn.ooo.ppp

A thing I noticed, the call Id in the invites is :
Call-ID: 1de93b843bc7a10275c36c145669e9d7 at aaa.bbb.ccc.ddd

whereas in the responses, it shows up as :
Call-ID: 1de93b843bc7a10275c36c145669e9d7 at 10.0.0.177

Is it because of this that * isn't able to recognize the response as the one to the original request?

I am using Asterisk 1.4.13 on Fedora 7.

Anybody faced similar issues? Any workarounds? or am I missing something?

Regards
- Benjamin Jacob.








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