Hi, All! Freeswitch-1 sends 200 OK to Freeswitch-2 via IPv6. Freeswitch-2 received these packets and it can be seen in sip trace. However Freeswitch-2 does not send ACK. recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:20:35.903592: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:20:37.903708: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:20:41.903776: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:20:45.904373: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:20:49.904423: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:20:53.905075: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ 2018-06-02 13:20:55.780247 [DEBUG] sofia_reg.c:2435 Changing expire time to 897 by request of proxy sip:ipvs.sipnet.ru:5061 recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:20:57.905810: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:21:01.905406: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck ------------------------------------------------------------------------ recv 1184 bytes from tls/[2a02:7b43:1eb0:eb21::2]:5061 at 13:21:05.905437: ------------------------------------------------------------------------ SIP/2.0 200 OK Via: SIP/2.0/TLS [2a02:f680:e0:1210::2123]:5061;branch=z9hG4bKZ2359mFaFv98p;rport=55317 From: "Extension 1000" <sip:1000@ [2a02:f680:e0:1210::2123]>;tag=y912pHDgNp3QF To: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061>;tag=pNyNt1y311K1F Call-ID: 6b3983f9-e0f1-1236-0d9d-525400af4b7f CSeq: 123631351 INVITE Contact: <sip:1000@[2a02:7b43:1eb0:eb21::2]:5061;transport=udp> User-Agent: FreeSWITCH-mod_sofia/1.6.19+git~20171120T163416Z~b1b21d0695~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY Supported: timer, path, replaces Allow-Events: talk, hold, conference, refer Content-Type: application/sdp Content-Disposition: session Content-Length: 339 X-FS-Display-Name: Outbound Call X-FS-Display-Number: sip:1000%@[2a02:7b43:1eb0:eb21::2] X-FS-Support: update_display,send_info v=0 o=FreeSWITCH 1527902766 1527902767 IN IP6 2a02:7b43:1eb0:eb21::2 s=FreeSWITCH c=IN IP6 2a02:7b43:1eb0:eb21::2 t=0 0 m=audio 32068 RTP/SAVP 8 101 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 a=crypto:1 AEAD_AES_256_GCM_8 inline:LshmymiWylaGtFqTrEo3mLmx5sVN0Th32k7FSPcjicE4sDva+ZM4tlP2gck So, Freeswitch-1 hangup: 2018-06-02 13:21:06.372001 [DEBUG] sofia.c:7084 Channel sofia/external-ipv6/1000@[2a02:f680:e0:1210::2123] entering state [terminating][0] 2018-06-02 13:21:06.372001 [NOTICE] sofia.c:8273 Hangup sofia/external-ipv6/1000@[2a02:f680:e0:1210::2123] [CS_EXECUTE] [NORMAL_UNSPECIFIED]