Sounds like a NAT issue. Use STUN if the client supports it. If not, use SER's nat support. -----Original Message----- From: serusers-bounces(a)iptel.org [mailto:serusers-bounces@lists.iptel.org] On Behalf Of Sebastian Kühner Sent: Friday, September 16, 2005 8:44 AM To: serusers(a)lists.iptel.org Subject: [Serusers] Authentication Hello, I want to authenticate the users that wants to make a PSTN call on every INVITE. I have one user that can't make PSTN calls, because the message "407 Proxy Authentication Required" goes back to the wrong port (the IP is correct). I checked it with ngrep. Has anyone of you an idea how could I fix that problem? Thanks! Sebastian _______________________________________________ Serusers mailing list serusers(a)lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers