I have a trouble, when FS start it register whit Siemens pbx, but after FS loses registration. I have a x-lite registered whit Siemens pbx and x-lite keeps register. I add whireshark trace thank you Diego ------------------------------------------------------ whireshark trace (register nok) VIA (x-lite): Via: SIP/2.0/UDP 192.168.0.125:27504;branch=z9hG4bK-d8754z-ed554d5f6c56a345-1---d8754z-;rport Transport: UDP Sent-by Address: 192.168.0.125 Sent-by port: 27504 Branch: z9hG4bK-d8754z-ed554d5f6c56a345-1---d8754z- RPort: rport Max-Forwards: 70 VIA (FS) Via: SIP/2.0/UDP 192.168.0.125:5080;rport;branch=z9hG4bKc2BX53H64t2ta Transport: UDP Sent-by Address: 192.168.0.125 Sent-by port: 5080 RPort: rport Branch: z9hG4bKc2BX53H64t2ta Max-Forwards: 70 To (x-lite) To: "135"<sip:135@192.168.0.120> SIP Display info: "135" SIP to address: sip:135@192.168.0.120 To (FS) To: <sip:134@192.168.0.120;transport=udp> SIP to address: sip:134@192.168.0.120 contact (x-lite) Contact: <sip:135@192.168.0.125:27504;rinstance=21711995165dd606> Contact Binding: <sip:135@192.168.0.125:27504;rinstance=21711995165dd606> URI: <sip:135@192.168.0.125:27504;rinstance=21711995165dd606> SIP contact address: sip:135@192.168.0.125:27504 contact (FS) Contact: <sip:gw+siemens3500@192.168.0.125:5080;tport=tcp;transport=udp> Contact Binding: <sip:gw+siemens3500@192.168.0.125:5080;tport=tcp;transport=udp> URI: <sip:gw+siemens3500@192.168.0.125:5080;tport=tcp;transport=udp> SIP contact address: sip:gw+siemens3500@192.168.0.125:5080 Expires: 0 ============================= FS start up whireshark trace (register ok) To: <sip:134@192.168.0.120;transport=udp> SIP to address: sip:134@192.168.0.120 Call-ID: 27c589ef-6e9a-5544-887a-52c0c7856977 Contact: <sip:gw+siemens3500@192.168.0.125:5080;tport=tcp;transport=udp> Contact Binding: <sip:gw+siemens3500@192.168.0.125:5080;tport=tcp;transport=udp> URI: <sip:gw+siemens3500@192.168.0.125:5080;tport=tcp;transport=udp> SIP contact address: sip:gw+siemens3500@192.168.0.125:5080 Expires: 120 Via: SIP/2.0/UDP 192.168.0.125:5080;rport;branch=z9hG4bKBB461XN46BmcK Transport: UDP Sent-by Address: 192.168.0.125 Sent-by port: 5080 RPort: rport Branch: z9hG4bKBB461XN46BmcK Max-Forwards: 70