This is the trace of the non-working call U 192.168.253.20:5060 -> 192.168.253.30:5080 SIP/2.0 181 Call Is Being Forwarded..Via: SIP/2.0/UDP 192.168.253.30:5080;branch=z9hG4bKtVJETaom;rport=5080;received=192.168.253.30..From: ;tag=29ED5EE2-5977424B0002E6E3-3E362700..To: ;tag=b27e1a1d33761e85846fc98f5f3a7e58.3d42..CSeq: 10 INVITE..Call-ID: 41EBFC40-5977424B0002E6E8-3E362700..Server: kamailio (4.3.6 (x86_64/linux))..Content-Length: 0.... # U 192.168.253.30:5080 -> 192.168.253.20:5060 SIP/2.0 181 Call Is Being Forwarded..Record-Route: ..Via: SIP/2.0/UDP 192.168.253.20;branch=z9hG4bK2345.16bf49fc0c980d55be48639d38491852.0..Via: SIP/2.0/UDP 192.168.253.60:50 60;branch=z9hG4bK9otb9d308g6uh5d1qqp0.1..From: ;tag=368B3B0F5153CB8D..Call-ID: D80A459899283550@86.103.164.122..CSeq: 1368 INVITE..To: ;tag=499413B3-5977424B0002E487-33B FB700..Server: kamailio (4.3.6 (x86_64/linux))..Contact: ..Content-Length: 0.... # U 192.168.253.20:5060 -> 192.168.253.30:5080 SIP/2.0 100 trying -- your call is important to us..Via: SIP/2.0/UDP 192.168.253.30:5080;branch=z9hG4bKtVJETaom;rport=5080;received=192.168.253.30..From: ;tag=29ED5EE2-5977424B0002E6E3-3E362700..To: < sip:04317097448@sip-pk.tng.de>..CSeq: 10 INVITE..Call-ID: 41EBFC40-5977424B0002E6E8-3E362700..Server: kamailio (4.3.6 (x86_64/linux))..Content-Length: 0.... # U 192.168.253.20:5060 -> 192.168.253.30:5080 SIP/2.0 180 Ringing..Via: SIP/2.0/UDP 192.168.253.30:5080;received=192.168.253.30;branch=z9hG4bKtVJETaom;rport=5080..From: ;tag=29ED5EE2-5977424B0002E6E3-3E362700..To: ;tag=as6c39bf14..CSeq: 10 INVITE..Call-ID: 41EBFC40-5977424B0002E6E8-3E362700..Record-Route: ..Server: Asterisk LocaPhone..Allow: INVITE, ACK, CANCEL, OPTI ONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH..Supported: replaces, timer..Session-Expires: 300;refresher=uac..Contact: ..Content-Length: 0..X-TNG-SBC-PeerIP: 82.97. 138.31..X-TNG-SBC-ACCESS-IP: 82.97.166.230.... This call (v 1.5.1) is working # U 192.168.253.71:5060 -> 192.168.253.72:5080 SIP/2.0 181 Your Call is being forwarded..Via: SIP/2.0/UDP 192.168.253.72:5080;branch=z9hG4bK60enuaO4;rport=5080;received=192.168.253.72..From: ;tag=3B251D63-5977463E000E0E59-60A5D700..To: ;tag=9dd61ff61e802d8e2bef5f14621ef3c2.30d3..CSeq: 10 INVITE..Call-ID: 025CFD37-5977463E000E0E5E-60A5D700..Server: kamailio (5.0.2 (x86_64/linux))..Content-Length: 0.... # U 192.168.253.72:5080 -> 192.168.253.71:5060 SIP/2.0 181 Your Call is being forwarded..Record-Route: ..Via: SIP/2.0/UDP 192.168.253.71;branch=z9hG4bKda03.ad3e46772240c0d40b685f3fe030ed54.0..Via: SIP/2.0/ UDP 192.168.253.71:5080;received=192.168.253.71;branch=z9hG4bKqOw42axV;rport=5080..From: ;tag=42EE0896-5977462A0009DE12-BB6C4700..CSeq: 10 INVITE..Call-ID: 0AD03C75-5977462A0009DE17-BB6C4700..To: ;tag=16BFA15F-5977463E000E0CD9-60457700..Server: kamailio (5.0.2 (x86_64/linux))..Contact: ..Content-Length: 0.... # U 192.168.253.71:5060 -> 192.168.253.72:5080 SIP/2.0 100 trying -- your call is important to us..Via: SIP/2.0/UDP 192.168.253.72:5080;branch=z9hG4bK60enuaO4;rport=5080;received=192.168.253.72..From: ;tag=3B251D63-5977463E000E0E59-60A5D700..To: ..CSeq: 10 INVITE..Call-ID: 025CFD37-5977463E000E0E5E-60A5D700..Server: kamailio (5.0.2 (x86_64/linux))..Content-Length: 0.... # U 192.168.253.71:5060 -> 192.168.253.72:5080 SIP/2.0 180 Ringing..Via: SIP/2.0/UDP 192.168.253.72:5080;received=192.168.253.72;branch=z9hG4bK60enuaO4;rport=5080..To: ;tag=01-08109-00a646d6-173a36813..CSeq: 10 INVITE..Call-ID: 025CFD37-5977463E000E 0E5E-60A5D700..From: ;tag=3B251D63-5977463E000E0E59-60A5D700..Record-Route: ..Allow: REFER,INVITE,NOTIFY,INFO,ACK,OPTIONS,REGIST ER,SUBSCRIBE..Contact: ..Server: Cirpack/v4.42j (gw_sip)..Content-Length: 0..X-TNG-SBC-PeerIP: 213.178.65.167..X-TNG-SBC-ACCESS-IP: 82.97.159.76.... # U 192.168.253.72:5080 -> 192.168.253.71:5060 SIP/2.0 180 Ringing..Record-Route: ..Via: SIP/2.0/UDP 192.168.253.71;branch=z9hG4bKda03.ad3e46772240c0d40b685f3fe030ed54.0..Via: SIP/2.0/UDP 192.168.253.71:50 80;received=192.168.253.71;branch=z9hG4bKqOw42axV;rport=5080..From: ;tag=42EE0896-5977462A0009DE12-BB6C4700..CSeq: 10 INVITE..Call-ID: 0AD03C75-5977462A0009DE17-BB6C4700..To: ;tag=16BFA15F-5977463E000E0CD9-60457700..Allow: REFER,INVITE,NOTIFY,INFO,ACK,OPTIONS,REGISTER,SUBSCRIBE..Server: Cirpack/v4.42j (gw_sip)..X-TNG-SBC-PeerIP: 213.178.65.167..X-TNG-SBC-ACCESS-IP: 82.97.159.76..Contact: ..Content-Length: 0.... #