Hi rafael,

I might be wrong.. but it's REALLY hard to know if a user is behind the
same nat.. due to that : 

on sip-proxy you see that user Alice and Bob come from the same IP, and
that they have the same "ip-range" in say contact. 

you say "Oh, we see he's behind the same nat.."
but..

you dont really know what other equitment the other user has behind
his nat. Say a user has 3 routers
router 1: 
192.168.1.1 on "inside"
193.212.1.10 on "outside"

router 2: is conected to inside of router 1: 
192.168.9.1 on "inside"
192.168.1.2 on "outside"

router 3: is concted to router 2's inside:
192.168.1.1 on "inside"
192.168.9.1 on "outside"

one phone is now connected to router 3, and one to router 1.

on router 3 the phone gets the "internal" ip: 192.168.1.2. 
on router 1 the phone gets the ip 192.168.1.3

the phone on router 1, can not send rtppackets to the phone on router
3.. and router 3, can not send to router 1.. evenwhilethey are "looking"
to be behind the same nat.

- Atle

ps: if anybody has a working solutio for this, exept ice/turn/stun
whatever it's now called.. fel free to update me :)

* Rafael J. Risco G.V. <rafael.risco@gmail.com> [070305 22:06]: