[Serusers] Unexpected disconnect - lost SIP packets?

Hello, I'm need some help with SIP protocol / SER configuration to resolve a problem. I have a system with a SER instance and a SIP client application running on the same box. SER is 10.50.32.10:5060 APP is 10.50.32.10:5070 Remote SIP server 10.1.39.10 Remote phone is 10.1.39.202 The user agent is registered with the SER instance as extension 1009. It has aliases 1001-1008 and is actually called as 231x which maps onto 100x which then connects to extension 1009. The remote phone makes a call to the user agent application via the remote SIP server and the SER instance. It dials 2311 which gets automagically converted to extension 1009 The call is established but the user application times out and detects a disconnect despite the calling phone not hanging up. In my wireshark trace it seems that SER is ignoring some form of keep-alive from the remote SIP server and this is causing the timeout. The lines of interest include 39, 42, 45, 50, 53, 56, 59 Lines 28 and others similar are on the loopback interface and are packets between port 5060 and 5070 Can someone please advise if the SIP protocol has problems and/or if SER configuration has problems? 22 0.218826 10.50.32.10 -> 127.0.0.1 SIP Request: REGISTER sip:localhost.localdomain 23 0.219570 127.0.0.1 -> 10.50.32.10 SIP Status: 200 OK (1 bindings) 24 19.472555 10.1.39.10 -> 10.50.32.10 SIP/SDP Request: INVITE sip:1001@butler.fesa.sto;transport=udp, with session description 25 19.473394 10.50.32.10 -> 10.1.39.10 SIP Status: 100 trying -- your call is important to us 26 19.473596 10.50.32.10 -> 10.50.32.10 SIP/SDP Request: INVITE sip:1009@10.50.32.10:5070;LINEID=1d5a67e38809, with session description 27 19.484244 10.50.32.10 -> 10.50.32.10 SIP Status: 100 Trying 28 19.725476 10.50.32.10 -> 10.50.32.10 SIP Status: 180 Ringing 29 19.725828 10.50.32.10 -> 10.1.39.10 SIP Status: 180 Ringing 32 21.770798 10.50.32.10 -> 10.50.32.10 SIP/SDP Status: 200 OK, with session description 33 21.782437 10.50.32.10 -> 10.1.39.10 SIP/SDP Status: 200 OK, with session description 38 21.789396 10.50.32.10 -> 10.1.39.202 RTCP Source port: 8001 Destination port: 16391 39 21.800069 10.1.39.10 -> 10.50.32.10 SIP Request: ACK sip:2311@10.50.32.10:5070;LINEID=1d5a67e38809 40 22.278096 10.50.32.10 -> 10.50.32.10 SIP/SDP Status: 200 OK, with session description 41 22.278713 10.50.32.10 -> 10.1.39.10 SIP/SDP Status: 200 OK, with session description 42 22.298101 10.1.39.10 -> 10.50.32.10 SIP Request: ACK sip:2311@10.50.32.10:5070;LINEID=1d5a67e38809 43 23.285536 10.50.32.10 -> 10.50.32.10 SIP/SDP Status: 200 OK, with session description 44 23.288988 10.50.32.10 -> 10.1.39.10 SIP/SDP Status: 200 OK, with session description 45 23.307839 10.1.39.10 -> 10.50.32.10 SIP Request: ACK sip:2311@10.50.32.10:5070;LINEID=1d5a67e38809 48 25.298214 10.50.32.10 -> 10.50.32.10 SIP/SDP Status: 200 OK, with session description 49 25.299105 10.50.32.10 -> 10.1.39.10 SIP/SDP Status: 200 OK, with session description 50 25.317892 10.1.39.10 -> 10.50.32.10 SIP Request: ACK sip:2311@10.50.32.10:5070;LINEID=1d5a67e38809 51 29.306496 10.50.32.10 -> 10.50.32.10 SIP/SDP Status: 200 OK, with session description 52 29.306758 10.50.32.10 -> 10.1.39.10 SIP/SDP Status: 200 OK, with session description 53 29.328420 10.1.39.10 -> 10.50.32.10 SIP Request: ACK sip:2311@10.50.32.10:5070;LINEID=1d5a67e38809 54 33.314736 10.50.32.10 -> 10.50.32.10 SIP/SDP Status: 200 OK, with session description 55 33.318736 10.50.32.10 -> 10.1.39.10 SIP/SDP Status: 200 OK, with session description 56 33.338302 10.1.39.10 -> 10.50.32.10 SIP Request: ACK sip:2311@10.50.32.10:5070;LINEID=1d5a67e38809 57 37.323175 10.50.32.10 -> 10.50.32.10 SIP/SDP Status: 200 OK, with session description 58 37.324791 10.50.32.10 -> 10.1.39.10 SIP/SDP Status: 200 OK, with session description 59 37.347936 10.1.39.10 -> 10.50.32.10 SIP Request: ACK sip:2311@10.50.32.10:5070;LINEID=1d5a67e38809 --> client detects disconnect here Thanks jeremy