[OpenSER-Users] stun

[Iñaki Baz Castillo]

El Tuesday 10 June 2008 13:59:42 Aymeric Moizard escribió:
> Stun can work even behind symmetric NAT if the stun server was
> running on the same socket the SIP server is running... I hope
> this feature will come soon!

Sure? AFAIK a symmetric NAT not only depends on the destination IP but also on 
the port. So unless you have a STUN server listening in all the ports 
available for RTP proxing you don't know if STUN will work.

Also, clients implementing STUN will refuse using STUN if they discover they 
are behind symmetric NAT. The STUN server needs 2 public IP's so probably 
each one will see a different public source port from the NAT router. In this 
case STUN will report "Symmetric NAT" so the client will not trust it.

For example Twinkle or Ekiga don't use STUN if STUN discovers they are behind 
symmetric NAT.

Mybe I'm forgotting something? :)






-- 
Iñaki Baz Castillo
ibc at in.ilimit.es