/mcpno mgcp fax-relay sg3-to-g3 no mgcp package fxr-package mgcp fax t38 inhibit no mgcp modem passthrough voip mode nse After the voice call is set up, the TGW sends a SIP ReINVITE to the OGW through CUBE. If the switchover is successful, the OGW responds with a SIP 200 OK with the correct Session Description Protocol (SDP) parameters. T.38 Switchover INVITE sip:2101@10.0.0.1:5060 SIP/2.0 Via: SIP/2.0/UDP 10.0.0.2:5060;branch=z9hG4bK171D71 Remote-Party-ID: sip:1101@10.0.0.2;party=calling;screen=no;privacy=off From: sip:8141101@10.0.0.2;tag=8D815D8-646 To: sip:2101@10.0.0.1;tag=DD4D344-21B2 Date: Fri, 25 Feb 2011 19:25:15 GMT Call-ID: 32395B08-403E11E0-818C9D5B-499FBE40@10.0.0.1 Supported: 100rel,timer,resource-priority,replaces,sdp-anat Min-SE: 1800 Cisco-Guid: 786980147-1077809632-2173148507-1235205696 User-Agent: Cisco-SIPGateway/IOS-12.x Allow: INVITE, OPTIONS, BYE, CANCEL, ACK, PRACK, UPDATE, REFER, SUBSCRIBE, NOTIFY, INFO, REGISTER CSeq: 101 INVITE Max-Forwards: 70 Timestamp: 1298661915 Contact: sip:8141101@10.0.0.2:5060 Expires: 180 Allow-Events: telephone-event Content-Type: application/sdp Content-Length: 384 v=0 o=CiscoSystemsSIP-GW-UserAgent 3745 9509 IN IP4 10.0.0.2 s=SIP Call c=IN IP4 10.0.0.2 t=0 0 m=image 17682 udptl t38 c=IN IP4 10.0.0.2 a=T38FaxVersion:0 a=T38MaxBitRate:7200 a=T38FaxFillBitRemoval:0 a=T38FaxTranscodingMMR:0 a=T38FaxTranscodingJBIG:0 a=T38FaxRateManagement:transferredTCF a=T38FaxMaxBuffer:200 a=T38FaxMaxDatagram:180 a=T38FaxUdpEC:t38UDPRedundancy !!NOTE!! Not all of the above bolded fields are required. The above is an example of how Cisco implements T38. SIP/2.0 100 Trying Via: SIP/2.0/UDP 10.0.0.2:5060;branch=z9hG4bK171D71 From: sip:8141101@10.0.0.2;tag=8D815D8-646 To: sip:2101@10.0.0.1;tag=DD4D344-21B2 Date: Fri, 25 Feb 2011 17:48:05 GMT Call-ID: 32395B08-403E11E0-818C9D5B-499FBE40@10.0.0.1 CSeq: 101 INVITE