[Serusers] SER, ATA-186 & Cisco AS5300

I hope this is not an FAQ, I've tried searching the available info. Using Ser 0.8.12, Cisco AS5300 with IOS 12.3.6 & a ATA-186. ATA-186 (behind NAT) -> SER -> AS5300 On the INVITE, we get: 10w6d: httpish_msg_process_network_msg: Content Length 261, Bytes Remaining 256 10w6d: HandleUdpSocketReads: SIP Message incomplete, trashed ser.cfg is just using t_relay_to_udp and not doing anything fancy. Any ideas!? Linus (Full debug from debug ccsip all) 10w6d: Received: INVITE sip:448000664901@gk.magrathea.net;user=phone SIP/2.0 Max-Forwards: 10 Record-Route: <sip:448000664901@213.166.5.135;ftag=651568306;lr=on> Via: SIP/2.0/UDP 213.166.5.135;branch=z9hG4bKbf06.7adc86c4.0 Via: SIP/2.0/UDP 213.162.109.118:5060 From: sip:linus@gk.magrathea.net;tag=651568306 To: <sip:448000664901@gk.magrathea.net;user=phone> Call-ID: 82733180(a)213.162.109.118 CSeq: 1 INVITE Contact: <sip:linus@213.162.109.118:5060;transport=udp> User-Agent: Cisco ATA 186 v2.16.1 ata18x (030709a) Expires: 300 Content-Length: 261 Content-Type: application/sdp v=0 o=linus 115389 115389 IN IP4 213.162.109.118 s=ATA186 Call c=IN IP4 213.162.109.118 t=0 0 m=audio 16384 RTP/AVP 4 8 0 101 a=rtpmap:4 G723/8000/1 a=rtpmap:8 PCMA/8000/1 a=rtpmap:0 PCMU/8000/1 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15 10w6d: httpish_msg_process_network_msg: Content Length 261, Bytes Remaining 256 10w6d: HandleUdpSocketReads: SIP Message incomplete, trashed