[Kamailio-Users] stun/outbound draft...

[Iñaki Baz Castillo]

2009/1/2 Aymeric Moizard <jack at atosc.org>:
>
> I have used the ser_stun.c/.h files to add STUN support
> on the socket of kamalio.
>
> I have modified the XOR-MAPPED-ADDRESS results because
> wireshark is not analysing it the same way although I'm
> not very sure who is right on this: wireshark versus ser.
>
> I hope you guys can work on merging and testing. Coming
> from ser, I guess the code is pretty good!


Let me a question. What is the purpose/advantage of having a STUN
server running in the SIP proxy/registrar port?
AFAIK this is just valid for a single purpose: allowing STUN *just for
SIP signalling* when the device is located behind symmetric NAT (in
which "normal" STUN doesn't work since the public mapping the router
assigns depends also on the destination ip:port, and not just on the
private source ip:port).

This is: having a STUN server running in port 5060 in the same host
where our SIP proxy/registrar runs is just valid for a UA behind
symmetric NAT because it can set the "Contact" header with the mapped
public ip:port, so it will be able to receive in-dialog requests
(without NAT solution at SIP level in the proxy), but it will never be
valid for RTP, since the destination of the RTP will never be
PROXY_IP:5060, so the mapping our symmetric NAT router will do for the
RTP is completely unknown.

So, what is the advantage of a STUN server in port 5060? Thanks.

-- 
Iñaki Baz Castillo
<ibc at aliax.net>