# U 10.0.0.67:50549 -> 10.0.0.19:5060 INVITE sip:1234@10.0.0.19:5060;ftag=2482904200;lr SIP/2.0..Via: SIP/2.0/UDP 10.0.0.67:5060..Fro m: ;tag=48235ADC-1DB8..To: ; tag=2482904200..Date: Thu, 07 Oct 2004 15:42:12 GMT..Call-ID: 137792672@10.0.0.35..Route: , ..Supported: timer,100rel..Min- SE: 1800..Cisco-Guid: 1053952464-397283801-2441193380-2221309272..User-Agent: Cisco-SIPGateway/IOS-12.x.. Allow: INVITE, OPTIONS, BYE, CANCEL, ACK, PRACK, COMET, REFER, SUBSCRIBE, NOTIFY, INFO..CSeq: 101 INVITE.. Max-Forwards: 6..Remote-Party-ID: ;party=calling;screen=no;privacy=off..Timestam p: 1097163732..Contact: ..Expires: 180..Allow-Events: telephon e-event..Content-Type: application/sdp..Content-Length: 402....v=0..o=CiscoSystemsSIP-GW-UserAgent 8783 11 68 IN IP4 10.0.0.67..s=SIP Call..c=IN IP4 10.0.0.67..t=0 0..m=image 18742 udptl t38..c=IN IP4 20 0.175.202.67..a=T38FaxVersion:0..a=T38MaxBitRate:14400..a=T38FaxFillBitRemoval:0..a=T38FaxTranscodingMMR:0 ..a=T38FaxTranscodingJBIG:0..a=T38FaxRateManagement:transferredTCF..a=T38FaxMaxBuffer:200..a=T38FaxMaxData gram:72..a=T38FaxUdpEC:t38UDPRedundancy.. # U 10.0.0.19:5060 -> 10.0.0.67:5060 SIP/2.0 100 Trying..Via: SIP/2.0/UDP 10.0.0.67:5060..From: ;tag=48235ADC-1DB8..To: ;tag=2482904200..Call-ID: 13 7792672@10.0.0.35..CSeq: 101 INVITE..Server: Sip Router..Content-Length: 0.... # ====The INVITE sent to the ATA has only one route header====== U 10.0.0.19:5060 -> 10.0.0.18:5071 INVITE sip:1234@10.0.0.18:5071 SIP/2.0..Record-Route: ..Via: SIP/2.0/UDP 10.0.0.19;branch=z9hG4bK2c09.8631afe3.0..Via: SIP/2.0/UDP 10.0.0.67:5060..Fr om: ;tag=48235ADC-1DB8..To: ; tag=2482904200..Date: Thu, 07 Oct 2004 15:42:12 GMT..Call-ID: 137792672@10.0.0.35..Route : ..Supported: timer,100rel..Min-SE: 1800..Cisco-Guid: 10539524 64-397283801-2441193380-2221309272..User-Agent: Cisco-SIPGateway/IOS-12.x..Allow: INVITE, OPTIONS, BYE, CA NCEL, ACK, PRACK, COMET, REFER, SUBSCRIBE, NOTIFY, INFO..CSeq: 101 INVITE..Max-Forwards: 5..Remote-Party-I D: ;party=calling;screen=no;privacy=off..Timestamp: 1097163732..Contact: ..Expires: 180..Allow-Events: telephone-event..Content-Type: applicat ion/sdp..Content-Length: 402....v=0..o=CiscoSystemsSIP-GW-UserAgent 8783 1168 IN IP4 10.0.0.67..s=SIP Call..c=IN IP4 10.0.0.67..t=0 0..m=image 18742 udptl t38..c=IN IP4 10.0.0.67..a=T38FaxVersion:0 ..a=T38MaxBitRate:14400..a=T38FaxFillBitRemoval:0..a=T38FaxTranscodingMMR:0..a=T38FaxTranscodingJBIG:0..a= T38FaxRateManagement:transferredTCF..a=T38FaxMaxBuffer:200..a=T38FaxMaxDatagram:72..a=T38FaxUdpEC:t38UDPRe dundancy.. # U 10.0.0.18:5071 -> 10.0.0.19:5060 SIP/2.0 488 Not Acceptable Here..Via: SIP/2.0/UDP 10.0.0.19;branch=z9hG4bK2c09.8631afe3.0..Via: SIP/2 .0/UDP 10.0.0.67:5060..From: ;tag=48235ADC-1DB8..To: < sip:55519@proxy.com;user=phone>;tag=2482904200..Call-ID: 137792672@10.0.0.35..CSeq: 101 IN VITE..timestamp: 1097163732..server: Cisco ATA 186 v3.1.0 atasip (040211A)..warning: Media type not avail able..Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER..Content-Length: 0.... # ===========The ACK sent to ATA has two route headers, and the top route header is the same as the R-Uri. ===========Is this correct? U 10.0.0.19:5060 -> 10.0.0.18:5071 ACK sip:1234@10.0.0.18:5071 SIP/2.0..Via: SIP/2.0/UDP 10.0.0.19;branch=z9hG4bK2c09.8631afe3.0..F rom: ;tag=48235ADC-1DB8..Call-ID: 137792672@10.0.0.35..To: ;tag=2482904200..CSeq: 101 ACK..Route: , ..User-Agent: Sip Router..Content-Length : 0.... # U 10.0.0.19:5060 -> 10.0.0.67:5060 SIP/2.0 488 Not Acceptable Here..Via: SIP/2.0/UDP 10.0.0.67:5060..From: ; tag=48235ADC-1DB8..To: ;tag=2482904200. .Call-ID: 137792672@10.0.0.35..CSeq: 101 INVITE..timestamp: 1097163732..server: Cisco ATA 186 v3.1.0 atas ip (040211A)..warning: Media type not available..Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER..Content-Length: 0.... # ===========Supposing that this ACK was not absorved by the proxy, what would be the behavior of loose_route()? ===========Wouldn't loose_route change the R-URI by the topmost router and then remove it? If so, this ACK ===========would be equal to the one previously sent by ser but it would have only one route header. Am I missing ===========something? U 10.0.0.67:50549 -> 10.0.0.19:5060 ACK sip:1234@10.0.0.19:5060;ftag=2482904200;lr SIP/2.0..Via: SIP/2.0/UDP 10.0.0.67:5060..From: ;tag=48235ADC-1DB8..To: ; tag=2482904200..Date: Thu, 07 Oct 2004 15:42:12 GMT..Call-ID: 137792672@10.0.0.35..Route: , ..Max-Forwards: 6..Content-Length: 0..CSeq: 101 ACK.... #