[Freeswitch-users] AASTRA Phones - NAT issue

[Paul Hayes]

On 17/10/14 18:53, Sean Devoy wrote:
> Right, because I would ask on here without Googling it first – come
> one.  I found how to do it for many AASTRA models, but nothing on the 480i.
>

The problem is that the Register from the phone itself is coming from 
port 5067 but when the packet arrives at FS, it's actually coming from 
port 5060 of the external IP address:


   recv 811 bytes from udp/[71.121.183.4]:5060 at 19:28:05.468752:

but:

   Via: SIP/2.0/UDP 71.121.183.4:5067;branch=z9hG4bKba321b220

So FS sends the response to 71.121.183.4:5067:

   send 667 bytes to udp/[71.121.183.4]:5067 at 19:28:05.470167

As per the SIP standard.  The router at the phone side will reject this 
as it'll be expecting something on port 5060.

rport would work-around this but if your phone doesn't support it then 
that's not an option.

I suspect this is the results of a SIP-ALG on the router at the phone 
end messing with things.

If rport isn't an option then I'd be looking to disable the SIP-ALG on 
the router.

cheers,
Paul.