[SR-Users] BLF issue with Kamailio behind NAT

Hello All, I have an integration with Kamailio and FusionPBX (Freeswitch) working great but I been trying to troubleshoot a BLF issue with Kamailio where the BLF seems to only work when Kamailio is on a Public IP rather than behind NAT. The BLF works fine when we register directly with Freeswitch either on a Public IP or behind NAT. Both Kamailio and FusionPBX (Freeswitch) are behind pfSense firewall on private IPs and registrations, Inbound and Outbound Calls etc are working fine. Just this BLF issue giving me some grief. The phone in question is a Yealink T20. I made some SIP Traces and I noticed the following: In the FS Message Header I see we have the SUBSCRIBE: ***** Begin Freeswitch trace**** Frame 13: 619 bytes on wire (4952 bits), 619 bytes captured (4952 bits) Internet Protocol Version 4, Src: 192.168.1.138 (192.168.1.138), Dst: 207.xx.xx.109 (207.xx.xx.109) User Datagram Protocol, Src Port: x11 (6062), Dst Port: ca-2 (5065) Session Initiation Protocol (REGISTER) Request-Line: REGISTER sip:testfs.mydomain.com:5065 SIP/2.0 Message Header Via: SIP/2.0/UDP 192.168.1.138:6062;branch=z9hG4bK748715490 From: "302" <sip:302@testfs.mydomain.com:5065>;tag=530545144 To: "302" <sip:302@testfs.mydomain.com:5065> Call-ID: 2118669441(a)192.168.1.138 CSeq: 8 REGISTER Contact: <sip:302@192.168.1.138:6062> Allow: INVITE, INFO, PRACK, ACK, BYE, CANCEL, OPTIONS, NOTIFY, REGISTER, SUBSCRIBE, REFER, PUBLISH, UPDATE, MESSAGE Max-Forwards: 70 User-Agent: Yealink SIP-T20P 9.72.0.30 Expires: 300 Allow-Events: talk,hold,conference,refer,check-sync Content-Length: 0 Frame 14: 698 bytes on wire (5584 bits), 698 bytes captured (5584 bits) Internet Protocol Version 4, Src: 207.xx.xx.109 (207.xx.xx.109), Dst: 192.168.1.138 (192.168.1.138) User Datagram Protocol, Src Port: ca-2 (5065), Dst Port: x11 (6062) Session Initiation Protocol (200) Status-Line: SIP/2.0 200 OK Message Header Via: SIP/2.0/UDP 192.168.1.138:6062 ;branch=z9hG4bK748715490;received=2.xx.xx.187;rport=6062 From: "302" <sip:302@testfs.mydomain.com:5065>;tag=530545144 To: "302" <sip:302@testfs.mydomain.com:5065>;tag=j71FeN5gcBjDe Call-ID: 2118669441(a)192.168.1.138 CSeq: 8 REGISTER Contact: <sip:302@192.168.1.138:6062 ;received=2.xx.xx.187:6062>;expires=300 Date: Thu, 24 Apr 2014 17:03:18 GMT User-Agent: FreeSWITCH-mod_sofia/1.2.23+git~20140419T040926Z~8a20da75ef~64bit Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE Supported: timer, path, replaces Content-Length: 0 Frame 15: 509 bytes on wire (4072 bits), 509 bytes captured (4072 bits) Internet Protocol Version 4, Src: 192.168.1.138 (192.168.1.138), Dst: 10.22.110.9 (10.22.110.9) User Datagram Protocol, Src Port: x11 (6062), Dst Port: ca-2 (5065) Session Initiation Protocol (SUBSCRIBE) Request-Line: SUBSCRIBE sip:301@10.22.110.9:5065 SIP/2.0 Message Header Via: SIP/2.0/UDP 192.168.1.138:6062;branch=z9hG4bK148600064 From: "302" <sip:302@testfs.mydomain.com:5065>;tag=2146254460 To: <sip:301@testfs.mydomain.com:5065>;tag=70uoBUVRvJyr Call-ID: 168472766(a)192.168.1.138 CSeq: 2 SUBSCRIBE Contact: <sip:302@192.168.1.138:6062> Accept: application/dialog-info+xml Max-Forwards: 70 User-Agent: Yealink SIP-T20P 9.72.0.30 Expires: 1800 Event: dialog Content-Length: 0 ****** End Freeswitch trace ******** In the Kamailio Header there is no SUBSCRIBE for the BLF. ***** Begin Kamailio trace**** Frame 17: 809 bytes on wire (6472 bits), 809 bytes captured (6472 bits) Internet Protocol Version 4, Src: 192.168.1.138 (192.168.1.138), Dst: 207.xx.xx.108 (207.xx.xx.108) User Datagram Protocol, Src Port: x11 (6062), Dst Port: sip (5060) Session Initiation Protocol (REGISTER) Request-Line: REGISTER sip:test.mydomain.com:5060 SIP/2.0 Message Header Via: SIP/2.0/UDP 192.168.1.138:6062;branch=z9hG4bK1572502835 From: "302" <sip:302@test.mydomain.com>;tag=1877226231 To: "302" <sip:302@test.mydomain.com> Call-ID: 887242692(a)192.168.1.138 CSeq: 3 REGISTER Contact: <sip:302@192.168.1.138:6062> Authorization: Digest username="302", realm="test.mydomain.com", nonce="U1lHHFNZRfB7/5Lyb/Rz3p/xu26B1lpE", uri="sip:test.mydomain.com:5060", response="7687c7d3141d1898e63a1cc9538f05d7", algorithm=MD5 Allow: INVITE, INFO, PRACK, ACK, BYE, CANCEL, OPTIONS, NOTIFY, REGISTER, SUBSCRIBE, REFER, PUBLISH, UPDATE, MESSAGE Max-Forwards: 70 User-Agent: Yealink SIP-T20P 9.72.0.30 Expires: 300 Allow-Events: talk,hold,conference,refer,check-sync Content-Length: 0 Frame 18: 496 bytes on wire (3968 bits), 496 bytes captured (3968 bits) Internet Protocol Version 4, Src: 207.xx.xx.108 (207.xx.xx.108), Dst: 192.168.1.138 (192.168.1.138) User Datagram Protocol, Src Port: sip (5060), Dst Port: x11 (6062) Session Initiation Protocol (200) Status-Line: SIP/2.0 200 OK Message Header Via: SIP/2.0/UDP 192.168.1.138:6062 ;branch=z9hG4bK1572502835;rport=6062;received=2.xx.xx.187 From: "302" <sip:302@test.mydomain.com>;tag=1877226231 To: "302" <sip:302@test.mydomain.com Call-ID: 887242692(a)192.168.1.138 CSeq: 3 REGISTER Contact: <sip:302@192.168.1.138:6062 Server: kamailio (4.0.6 (x86_64/linux)) Content-Length: 0 Frame 19: 316 bytes on wire (2528 bits), 316 bytes captured (2528 bits) Internet Protocol Version 4, Src: 207.xx.xx.108 (207.xx.xx.108), Dst: 192.168.1.138 (192.168.1.138) User Datagram Protocol, Src Port: sip (5060), Dst Port: x11 (6062) Session Initiation Protocol (OPTIONS) Request-Line: OPTIONS sip:2.xx.xx.187:6062 SIP/2.0 Message Header Via: SIP/2.0/UDP 10.22.110.11:5060;branch=0 From: sip:pinger@kamailio.org ;tag=uloc-53579917-4e9-89-0b632cbb-a8aa99c To: sip:2.xx.xx.187:6062 Call-ID: f9749d7-2d0b0be7-c678c54(a)10.22.110.11 CSeq: 1 OPTIONS Content-Length: 0 ***** End Kamailio trace**** Anyone faced this issue or have any ideas? regards, Errol