Hi....
please  forgive me in egnlish......
Below  one is log  file....
sip_domain= public_ip
It s not hung upping.......
openser server system ip 192.168.2.75
And UAC are   outside the NAT
The media is fine..... but not hung  upping at a same time.....
I think the record router  is  not correct... which is red  color  marked one......

59.93.74.129:41010 -> 192.168.2.75:5060
  INVITE sip:9001@public_ip SIP/2.0..Via: SIP/2.0/UDP 59.93.74.129:5060;rport;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara < sip:9002@6
  1.17.248.68>;tag=587704647..To: <sip:9001@public_ip>..Contact: <sip:9002@59.93.74.129:5060>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.
  34..CSeq: 35636 INVITE..Max-Forwards: 70..Content-Type: application/sdp..User-Agent: X-Lite release 1105x..Content-Length: 305....v=0..o=9002 35180894 3
  5180906 IN IP4 59.93.74.129..s=X-Lite..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pcmu/8000..a=rtpmap:8 pcma/8000..a
  =rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a=sendrecv..
#
U 192.168.2.75:5060 -> 59.93.74.129:41010
  SIP/2.0 100 trying -- your call is important to us..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From:
   sunkara <sip:9002@public_ip>;tag=587704647..To: <sip:9001@public_ip>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34 ..CSeq: 35636 INV
  ITE..Server: OpenSer (1.1.0-notls (i386/linux))..Content-Length: 0..Warning: 392 192.168.2.75:5060 "Noisy feedback tells:  pid=4700 req_src_ip=59.93.74.
  129 req_src_port=41010 in_uri=sip:9001@public_ip out_uri=sip:9001@59.93.74.129:5060 via_cnt==1"....
#
U 192.168.2.75:5060 -> 59.93.74.129:5060
  INVITE sip:9001@59.93.74.129:5060 SIP/2.0..Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647>..Via: SIP/2.0/UDP 192.168.2.75;branch=z9hG4bKf13d.ace6b
  487.0..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public _ip>;tag=58770464
  7..To: <sip:9001@public_ip>..Contact: <sip:9002@59.93.74.129:5060>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636 INVITE..M
  ax-Forwards: 69..Content-Type: application/sdp..User-Agent: X-Lite release 1105x..Content-Length: 305....v=0..o=9002 35180894 35180906 IN IP4 59.93.74.1
  29..s=X-Lite..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pcmu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtp
  map:98 iLBC/8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a=sendrecv..
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  SIP/2.0 100 Trying..Via: SIP/2.0/UDP 192.168.2.75;branch= z9hG4bKf13d.ace6b487.0;received=public_ip..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;br
  anch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag=587704647..To: < sip:9001@public_ip>;tag=2115499902..Contact:
  <sip:9001@59.93.74.129:5060>..Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34 ..CSeq: 3
  5636 INVITE..Server: X-Lite release 1105x..Content-Length: 0....
#
U 59.93.74.129:41010 -> 192.168.2.75:5060
  ..
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  SIP/2.0 180 Ringing..Via: SIP/2.0/UDP 192.168.2.75;branch= z9hG4bKf13d.ace6b487.0;received=public_ip..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;b
  ranch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag=587704647..To: < sip:9001@public_ip>;tag=2115499902..Contact:
   <sip:9001@59.93.74.129:5060>..Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647> ..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq:
  35636 INVITE..Server: X-Lite release 1105x..Content-Length: 0....
#
U 192.168.2.75:5060 -> 59.93.74.129:41010
  SIP/2.0 180 Ringing..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip
  >;tag=587704647..To: <sip:9001@public_ip>;tag=2115499902..Contact: <sip:9001@59.93.74.129:5060>..Record-Route: <sip: 192.168.2.75;lr=on;ftag=587704647
  >..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636 INVITE..Server: X-Lite release 1105x..Content-Length: 0....
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  ..
#
U 59.93.74.129:41010 -> 192.168.2.75:5060
  ..
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 192.168.2.75;branch=z9hG4bKf13d.ace6b487.0;received=public_ip..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch
  =z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara < sip:9002@public_ip>;tag=587704647..To: <sip:9001@public_ip>;tag=2115499902..Contact: <sip
  :9001@59.93.74.129:5060>..Record-Route: <sip: 192.168.2.75;lr=on;ftag=587704647>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636
   INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Length: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite
  ..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pcmu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/ 8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a=sendrecv..
#
U 192.168.2.75:5060 -> 59.93.74.129:41010
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 59.93.74.129:5060 ;rport=41010;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag
  =587704647..To: <sip:9001@public_ip>;tag=2115499902..Contact: <sip:9001@59.93.74.129:5060>.. Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647>..Ca
  ll-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636 INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Lengt
  h: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pc
  mu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a
  =sendrecv..
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  ..
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 192.168.2.75;branch=z9hG4bKf13d.ace6b487.0;received=public_ip..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch
  =z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag=587704647..To: <sip:9001@public_ip>;tag=2115499902..Contact: <sip
  :9001@59.93.74.129 :5060>..Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636
   INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Length: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite
  ..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pcmu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/
  8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a=sendrecv..
#
U 192.168.2.75:5060 -> 59.93.74.129:41010
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag
  =587704647..To: < sip:9001@public_ip>;tag=2115499902..Contact: <sip:9001@59.93.74.129:5060>..Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647> ..Ca
  ll-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636 INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Lengt
  h: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pc
  mu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a
  =sendrecv..
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 192.168.2.75 ;branch=z9hG4bKf13d.ace6b487.0;received=public_ip..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch
  =z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public _ip>;tag=587704647..To: <sip:9001@public_ip>;tag=2115499902..Contact: <sip
  :9001@59.93.74.129:5060>..Record-Route: <sip: 192.168.2.75;lr=on;ftag=587704647>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636
   INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Length: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite
  ..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pcmu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/
  8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a=sendrecv..
#
U 192.168.2.75:5060 -> 59.93.74.129:41010
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 59.93.74.129:5060 ;rport=41010;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag
  =587704647..To: <sip:9001@public_ip>;tag=2115499902..Contact: <sip:9001@59.93.74.129:5060>. .Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647>..Ca
  ll-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636 INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Lengt
  h: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pc
  mu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a
  =sendrecv..
#
U 59.93.74.129:41010 -> 192.168.2.75:5060
  ..
#
U 59.93.74.129:5060 -> 192.168.2.75:5060
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 192.168.2.75;branch=z9hG4bKf13d.ace6b487.0;received=public_ip..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch
  =z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag=587704647..To: <sip:9001@public_ip>;tag=2115499902..Contact: <sip
  :9001@59.93.74.129 :5060>..Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647>..Call-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636
   INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Length: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite
  ..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pcmu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/
8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a=sendrecv..
#
U 192.168.2.75:5060 -> 59.93.74.129:41010
  SIP/2.0 200 Ok..Via: SIP/2.0/UDP 59.93.74.129:5060;rport=41010;branch=z9hG4bKBEFDBAE75F0B4E22BC1C19062F5552F8..From: sunkara <sip:9002@public_ip>;tag
  =587704647..To: < sip:9001@public_ip>;tag=2115499902..Contact: <sip:9001@59.93.74.129:5060>..Record-Route: <sip:192.168.2.75;lr=on;ftag=587704647> ..Ca
  ll-ID: 05566ACF-9B85-4F75-ABAC-64118C1C988E@192.168.2.34..CSeq: 35636 INVITE..Content-Type: application/sdp..Server: X-Lite release 1105x..Content-Lengt
  h: 305....v=0..o=9001 13517410 13530387 IN IP4 59.93.74.129..s=X-Lite..c=IN IP4 59.93.74.129..t=0 0..m=audio 8000 RTP/AVP 1 8 3 98 97 101..a=rtpmap:1 pc
  mu/8000..a=rtpmap:8 pcma/8000..a=rtpmap:3 gsm/8000..a=rtpmap:98 iLBC/8000..a=rtpmap:97 speex/8000..a=rtpmap:101 telephone-event/8000..a=fmtp:101 0-15..a
  =sendrecv..

                                                                                                                                                        
--
Thanks and Regards with cheers
Sunkara Ravi Prakash (Voip Developer)
Hyperion Technology
www.hyperion-tech.com
+91-9985077535