Hello, here is an other diagram for people who don't yet understand what i expect to do. Look at sip_call_flow.png file i wish to substitute ondo sip server with ser and ondo pbx with asterisk . ondo sip server is able to do far-end near-end nat I guess ser too. I do hope i will find some people who help me to configure that . Regards Harry ___________________________________________________________________________ Appel audio GRATUIT partout dans le monde avec le nouveau Yahoo! Messenger Téléchargez cette version sur http://fr.messenger.yahoo.com