[Users] Problem with TCP INVITE being bridged by OpenSER to UDP

I have a scenario where user Alice registered with OpenSER with UDP port 5070. Then, I have user Bob sending an invite to Alice via the OpenSER using TCP. Hence, OpenSER is bridging my TCP SIP requests to UDP (and vice versa for the responses). Here is the sequence: Alice ----- TCP Invite -----> OpenSER ---------- UDP Invite ------ Alice responds back with 180 ringing, then 200 Ok. Upon getting the 200 OK, Bob sends an ACK (to complete the INVITE), followed by an Immediate BYE. THE TROUBLE IS...... the ACK and the BYE that Bob sends are dropped by OpenSER, and never forwarded onto Alice!!!! I see nothing wrong with the messages. WHat is happening? sip:~ russdaigle$ sudo tcpdump -i en0 -A -q -s 2000 port 5060 Password: tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on en0, link-type EN10MB (Ethernet), capture size 2000 bytes The following shows an sip-invite-bye from mutator using TCP to mjsip (via OPENSER). Everything after the ACK is dropped and not sent on. Then, is a similar but UDP exchange. In that case, we get a 404 not found in response to the BYE!!! 01:17:59.553909 IP 10.10.2.6.50135 > 10.10.1.234.sip: tcp 588 INVITE sip:alice@siptest2.com:5060 SIP/2.0 Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah To: Alice <sip:alice@siptest2.com:5060> CSeq: 1 INVITE Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com Contact: <sip:bob@10.10.2.6>;transport=TCP Max-Forwards: 70 Content-Type: application/sdp Content-Length: 195 v=0 o=- 817933771 817933775 IN IP4 10.10.2.6 s=darkness c=IN IP4 10.10.2.6 t=0 0 m=audio 5000 RTP/AVP 0 4 97 a=rtpmap:0 PCMU/8000 a=rtpmap:4 G723/8000/1 a=rtpmap:97 telephone-event/8000 01:17:59.554929 IP 10.10.1.234.sip > 10.10.2.6.50135: tcp 536 SIP/2.0 100 trying -- your call is important to us Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah To: Alice <sip:alice@siptest2.com:5060> CSeq: 1 INVITE Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com Server: OpenSer (1.1.0-notls (i386/darwin)) Content-Length: 0 Warning: 392 10.10.1.234:5060 "Noisy feedback tells: pid=11962 req_src_ip=10.10.2.6 req_src_port=50135 in_uri=sip:alice@siptest2.com: 5060 out_uri=sip:alice@10.10.2.6:5070 via_cnt==1" 01:17:59.555035 IP 10.10.1.234.sip > 10.10.2.6.5070: UDP, length 814 INVITE sip:alice@10.10.2.6:5070 SIP/2.0 Record-Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Record-Route: <sip: 10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> Via: SIP/2.0/UDP 10.10.1.234;branch=z9hG4bK9316.e5ab8ce2.0;i=b1 Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah To: Alice <sip:alice@siptest2.com:5060> CSeq: 1 INVITE Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com Contact: <sip:bob@10.10.2.6>;transport=TCP Max-Forwards: 69 Content-Type: application/sdp Content-Length: 195 P-hint: usrloc applied v=0 o=- 817933771 817933775 IN IP4 10.10.2.6 s=darkness c=IN IP4 10.10.2.6 t=0 0 m=audio 5000 RTP/AVP 0 4 97 a=rtpmap:0 PCMU/8000 a=rtpmap:4 G723/8000/1 a=rtpmap:97 telephone-event/8000 01:17:59.667962 IP 10.10.2.6.5070 > 10.10.1.234.sip: UDP, length 364 SIP/2.0 100 Trying Via: SIP/2.0/UDP 10.10.1.234;branch=z9hG4bK9316.e5ab8ce2.0;i=b1 Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 To: Alice <sip:alice@siptest2.com:5060> From: Bob <sip:bob@siptest2.com>;tag=fromhackblah Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com CSeq: 1 INVITE Server: mjsip stack 1.6 Content-Length: 0 01:17:59.699680 IP 10.10.2.6.5070 > 10.10.1.234.sip: UDP, length 505 SIP/2.0 180 Ringing Via: SIP/2.0/UDP 10.10.1.234;branch=z9hG4bK9316.e5ab8ce2.0;i=b1 Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 Record-Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Record-Route: <sip: 10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> To: Alice <sip:alice@siptest2.com:5060> From: Bob <sip:bob@siptest2.com>;tag=fromhackblah Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com CSeq: 1 INVITE Server: mjsip stack 1.6 Content-Length: 0 01:17:59.699683 IP 10.10.2.6.5070 > 10.10.1.234.sip: UDP, length 728 SIP/2.0 200 OK Via: SIP/2.0/UDP 10.10.1.234;branch=z9hG4bK9316.e5ab8ce2.0;i=b1 Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 Record-Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Record-Route: <sip: 10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> To: Alice <sip:alice@siptest2.com:5060>;tag=7c452a3254b2e183 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com CSeq: 1 INVITE Contact: <sip:alice@192.168.0.3:5070> Server: mjsip stack 1.6 Content-Length: 135 Content-Type: application/sdp v=0 o=- 817933771 817933775 IN IP4 10.10.2.6 s=darkness c=IN IP4 192.168.0.3 t=0 0 m=audio 21000 RTP/AVP 0 a=rtpmap:0 PCMU/8000 01:17:59.700273 IP 10.10.1.234.sip > 10.10.2.6.50135: tcp 440 SIP/2.0 180 Ringing Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 Record-Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Record-Route: <sip: 10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> To: Alice <sip:alice@siptest2.com:5060> From: Bob <sip:bob@siptest2.com>;tag=fromhackblah Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com CSeq: 1 INVITE Server: mjsip stack 1.6 Content-Length: 0 01:17:59.700299 IP 10.10.1.234.sip > 10.10.2.6.50135: tcp 663 SIP/2.0 200 OK Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 Record-Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Record-Route: <sip: 10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> To: Alice <sip:alice@siptest2.com:5060>;tag=7c452a3254b2e183 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com CSeq: 1 INVITE Contact: <sip:alice@192.168.0.3:5070> Server: mjsip stack 1.6 Content-Length: 135 Content-Type: application/sdp v=0 o=- 817933771 817933775 IN IP4 10.10.2.6 s=darkness c=IN IP4 192.168.0.3 t=0 0 m=audio 21000 RTP/AVP 0 a=rtpmap:0 PCMU/8000 01:17:59.804566 IP 10.10.2.6.50135 > 10.10.1.234.sip: tcp 435 ACK sip:alice@siptest2.com:5060 SIP/2.0 Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Route: <sip:10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK59972 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah To: Alice <sip:alice@siptest2.com:5060>;tag=7c452a3254b2e183 CSeq: 1 ACK Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com Max-Forwards: 70 01:17:59.839493 IP 10.10.2.6.50135 > 10.10.1.234.sip: tcp 435 BYE sip:alice@siptest2.com:5060 SIP/2.0 Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Route: <sip:10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK68444 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah To: Alice <sip:alice@siptest2.com:5060>;tag=7c452a3254b2e183 CSeq: 2 BYE Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com Max-Forwards: 70 01:18:00.199306 IP 10.10.2.6.5070 > 10.10.1.234.sip: UDP, length 728 SIP/2.0 200 OK Via: SIP/2.0/UDP 10.10.1.234;branch=z9hG4bK9316.e5ab8ce2.0;i=b1 Via: SIP/2.0/TCP 10.10.2.6:50135;branch=z9hG4bK85478043 Record-Route: <sip:10.10.1.234;r2=on;lr=on;ftag=fromhackblah> Record-Route: <sip: 10.10.1.234;transport=tcp;r2=on;lr=on;ftag=fromhackblah> To: Alice <sip:alice@siptest2.com:5060>;tag=7c452a3254b2e183 From: Bob <sip:bob@siptest2.com>;tag=fromhackblah Call-ID: SYRGNUXWKNZNXXPXUAMUTJXXPPMXWKVJFAXUNUUTGG(a)musecurity.com CSeq: 1 INVITE Contact: <sip:alice@192.168.0.3:5070> Server: mjsip stack 1.6 Content-Length: 135 Content-Type: application/sdp v=0 o=- 817933771 817933775 IN IP4 10.10.2.6 s=darkness c=IN IP4 192.168.0.3 t=0 0 m=audio 21000 RTP/AVP 0 a=rtpmap:0 PCMU/8000