Try "siproxd" http://sourceforge.net/projects/siproxd/ Siproxd is an proxy/masquerading daemon for the SIP protocol. It handles registrations of SIP clients on a private IP network and performs rewriting of the SIP message bodies to make SIP connections possible via a masquerading firewall. It allows SIP clients (like kphone, linphone) to work behind an IP masquerading firewall or router. I tried b2bua from Vocal - but I think it does not support NAT traversal yet. Regards, Dhiraj -----Original Message----- From: Alex [mailto:alexandre.fiaux@eivd.ch] Sent: 24 October 2003 11:14 To: serusers(a)lists.iptel.org Subject: [Serusers] Outbound proxy Hello! I want to realize the following setup: [serUser]<----------------------------------->[Nat]<----------------------------------->[UA] (private network) (public network) Can I do this using a B2BUA, and does somebody already do that? Whether not, do I have to modifiy something in my ser configuration to allow the UA on the public network to reach the serUser on the private network? Alex