[Asterisk-Users] Talking to other SIP hosts, wrong IP

[Juan J. Sierralta P.]

On Mon, 2003-09-15 at 22:35, Shaun Ewing wrote:
> As per my problem yesterday with the Cisco 7960 and getting it talking to
> Asterisk on a different subnet, I gave up trying and just put the Asterisk
> box back on the internal subnet.
> 
> However, I made two changes:
> 
> - the external IP address is set on an ethernet alias eth0:0
> - the main Linux router will change outgoing requests from 10.1.1.2 to the
> external IP (rather than the default behaviour of NAT)  - this seems to work
> fine in testing.
> 
> However, I've been trying to register with FWD.
> 
> If I set the default gateway to be 10.1.0.1, Asterisk tries to register with
> "Contact: <sip:xxxxx at 10.1.1.2>" (xxxxx = FWD number). Naturally FWD doesn't
> like this.
> 
> If I set the default gateway to be the public IP, Asterisk tries to regster
> with "Contact: <sip:xxxxx at 127.0.0.1>".
> 
> Does anybody know of a way I can tell external SIP gateways that I'm
> @203.x.x.x whilst leaving the internal @10.1.1.2 ?

	This is the same problem I have trying to register to a SER server
while * was behind NAT.
	I think if I found some spare time I´ll try to patch sip channel in
order to register it´s internal IP address and then try the external.
The idea is the same that Cisco ATAs uses, they register its own IP,
when they receive the OK response most SIP servers add a
"received=someip" where that someip is the IP address from they received
the REGISTER request, normally our external IP address; so we unregister
the first and register the external IP and change the Contact
accordingly.

-- 
Juan J. Sierralta P. <juanjo at atmlab.utfsm.cl>
UTFSM