I believe that we have identified a bug in SER related to limitations in the size of the SIP message SER will t_relay. This bug is easily reproducible and is described as follows:

Infrastructure description:

Internet <-> SER/rtpproxy 8.14 <-> Asterisk SIP2PSTN GW

1.) In my setup, I am using Asterisk as a SIP2PSTN gateway. 2.) Asterisk is deployed on a non-routable address segment. 3.) I have SER/rtpproxy 8.14 deployed on an internet routable segment. 4.) Users register to SER at the DMZ border. 5.) When a user makes a telephone call, SER t_relay's the INVITE in Asterisk 6.) During call setup, rtpproxy is used to connect rtp from the caller to the Asterisk GW.

Problem description:

With the current setup, a user can take a phone such as a Cisco 7960 or Xten soft phone and successfully register, make calls, and receive calls. These clients may be behind NAT firewalls. SER is resolving NAT configuration issues with the assistance of the NAThelper module. Recently, we began testing with products from Ingate and Jasomi. Customers are intent on using these vendor supplied solutions to enable UA's hosted on their corporate intranets to access external sip services. Each solution is deployed in a similar manner. This architecture is described as follows:

1.) An Ingate or Jasomi is deployed on an internet routable segment. 2.) A second ingate or Jasomi is deployed on a non-routable intranet facing segment. 3.) An ipsec tunnel is constructed between the two ingates.

In this segment, UA's on the intranet use the intranet Ingate or Jasomi as a standard SIP proxy to access external SIP services. To facilitate this, both are configured in a "hard forward" manner to push SIP traffic across the ipsec tunnel to the seconds Ingate or Jasomi. We have successfully registered from the intranet to our internet facing SER implementation through this setup. We are also able to make calls from our intranet through this proxy setup internet facing 3rd party SIP end points. However, when we attempt to send an INVITE to our SER/rtpproxy infrastructure, SER truncates the INVITE when it is forwarded to our Asterisk GW. Asterisk follows through with the INVITE process and will ring the intended phone. However, when the called party answers, Asterisk is unable to complete call setup because the "a" and "m" parameters are missing from the SDP. At this point the called party is dropped and the Ingate and the UA are left waiting for the RTP or a BYE that never comes.

From our observation, this problem is due to the size of the SIP INVITE,

which is sent to SER. Both Ingate and Jasomi create additional VIA parameters in the SIP INVITE in order to store state information. This state information is stored in encrypted strings in the xdata field of the VIA. It seems that the addition of these VIA fields increases the size of the SIP message beyond the SER's limits causing truncation upon relay. When the INVITE is t_relay'ed, much of the SDP is missing.

Please see the following ngrep of the SIP INVITE being relayed. I have replaced all pertinent address information for our own disclosure purposes.

______________________________________________ Device list: Ingate: 10.1.1.1 SER: 10.2.2.2/sbc1.mydomain.com Xten UA: 10.3.3.3 Asterisk gw: 10.4.4.4

## U 10.1.1.1:5060 -> 10.2.2.2:5060 INVITE sip:16179086547@sbc1.mydomain.com SIP/2.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK8d1c8a92109d8a370c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK94ce1c153879cbc60c7f7299b985c8f4.0;xdata=UkrU+mWJL aKZXFCdTMwK3YcFmw9BXXO0mZ-oXaK-fZQ_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;rport=35060;branc h=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;xdata=8BnRlTLlFQxaEMygbWSMP79K bMGMDOh+FcKZmz3mvlR09UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com. Contact: sip:esF1vz2EczTjGzG7n6VSFaJSXkL7bF2zwIo3bfnGcryex2fyUkto0gwwTTREPunT71- RsgM6xtWrz8Yc_PUuyGwcHdfV0OieldqEwsaPMEJLsA5in1v1fKYFFWpWOtqrj@10.1.1.1 . Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12666 INVITE. Max-Forwards: 68. Content-Type: application/sdp. User-Agent: X-Lite release 1103m. Record-Route: sip:dd4f232@10.1.1.1;lr. Record-Route: sip:eDpENJ1vtGdOGot7umZmcMs7cLQcpirjPwNAsYLWoPXQlOnCIQZXXwov084odkZ_h@1 0.1.1.1;lr. Content-Length: 230. . v=0. o=6173164000 94360252 94360262 IN IP4 10.1.1.1. s=X-Lite. c=IN IP4 10.1.1.1. t=0 0. m=audio 58192 RTP/AVP 0 8 101. a=rtpmap:0 pcmu/8000. a=rtpmap:8 pcma/8000. a=rtpmap:101 telephone-event/8000. a=fmtp:101 0-15.

# U 10.2.2.2:5060 -> 10.1.1.1:5060 SIP/2.0 407 Proxy Authentication Required. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK8d1c8a92109d8a370c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK94ce1c153879cbc60c7f7299b985c8f4.0;xdata=UkrU+mWJL aKZXFCdTMwK3YcFmw9BXXO0mZ-oXaK-fZQ_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;rport=35060;branc h=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;xdata=8BnRlTLlFQxaEMygbWSMP79K bMGMDOh+FcKZmz3mvlR09UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=b27e1a1d33761e85846fc98f5f3a7e58 .6c1d. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12666 INVITE. Proxy-Authenticate: Digest realm="sbc1.mydomain.com", nonce="4140d569a58f4230a925f11b564c223a856b792a". Server: Sip EXpress router (0.8.14 (i386/linux)). Content-Length: 0. Warning: 392 10.2.2.2:5060 "Noisy feedback tells: pid=26357 req_src_ip=10.1.1.1 req_src_port=5060 in_uri=sip:16179086547@sbc1.mydomain.com out_uri=sip:16179086547@sbc1.mydomain.com via_cnt==3". .

# U 10.1.1.1:5060 -> 10.2.2.2:5060 ACK sip:16179086547@sbc1.mydomain.com SIP/2.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK8d1c8a92109d8a370c7f7299b985c8f4.0. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=b27e1a1d33761e85846fc98f5f3a7e58 .6c1d. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12666 ACK. Content-Length: 0. .

# U 10.1.1.1:5060 -> 10.2.2.2:5060 15763@0:1480 .......0INVITE sip:16179086547@sbc1.mydomain.com SIP/2.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com. Contact: sip:e2AyJyUQgCGf_Y06tu_rM3e-U3sthj-vO8pYWVWTJVaikNLrDMx5XcCCLEBXvjyirBs hBuEUU_feciI091Ig8MNh7KZJzeH1d4fC7EsItfCfsA5in1v1fKYFFWpWOtqrj@10.1.1.1 . Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. Proxy-Authorization: Digest username="6173164000",realm="sbc1.mydomain.com",nonce="4140d569a58f4230a 925f11b564c223a856b792a",response="e9a140cc3bad75e35c6a96449ff7cc41",uri ="sip:16179086547@sbc1.mydomain.com". Max-Forwards: 68. Content-Type: application/sdp. User-Agent: X-Lite release 1103m. Record-Route: sip:dd4f232@10.1.1.1;lr. Record-Route: sip:e7DlN09kmHaZbabZRm9W0bzJ0uoyUyFM0PVyKvgCloKvDqsLXMsCA6nvRkR8LsbRi@1 0.1.1.1;lr. Content-Length: 230. . v=0. o=6173164000 94360252 94360262 IN IP4 10.1.1.1. s=X-Lite. c=IN IP4 10.1.1.1. t=0 0. m=audio 58194 RTP/AVP 0 8 101. a=rtpmap:0 pcmu/8000. a=rtpmap:8 pcma # U 10.2.2.2:5060 -> 10.1.1.1:5060 SIP/2.0 100 trying -- your call is important to us. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. Server: Sip EXpress router (0.8.14 (i386/linux)). Content-Length: 0. Warning: 392 10.2.2.2:5060 "Noisy feedback tells: pid=26356 req_src_ip=10.1.1.1 req_src_port=5060 in_uri=sip:16179086547@sbc1.mydomain.com out_uri=sip:16179086547@10.4.4.4:5060 via_cnt==3". .

# U 10.2.2.2:5060 -> 10.4.4.4:5060 64701@0:1480 .......qINVITE sip:16179086547@10.4.4.4:5060 SIP/2.0. Record-Route: sip:16179086547@10.2.2.2;ftag=4167926089;lr=on. Via: SIP/2.0/UDP 10.2.2.2;branch=z9hG4bKa01f.bbf787d1.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com. Contact: sip:e2AyJyUQgCGf_Y06tu_rM3e-U3sthj-vO8pYWVWTJVaikNLrDMx5XcCCLEBXvjyirBs hBuEUU_feciI091Ig8MNh7KZJzeH1d4fC7EsItfCfsA5in1v1fKYFFWpWOtqrj@10.1.1.1 . Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. Proxy-Authorization: Digest username="6173164000",realm="sbc1.mydomain.com",nonce="4140d569a58f4230a 925f11b564c223a856b792a",response="e9a140cc3bad75e35c6a96449ff7cc41",uri ="sip:16179086547@sbc1.mydomain.com". Max-Forwards: 67. Content-Type: application/sdp. User-Agent: X-Lite release 1103m. Record-Route: sip:dd4f232@10.1.1.1;lr. Record-Route: sip:e7DlN09kmHaZbabZRm9W0bzJ0uoyUyFM0PVyKvgCloKvDqsLXMsCA6nvRkR8LsbRi@1 0.1.1.1;lr. Content-Length: 230. . v=0. o=6173164000 94360252 94360262 I # U 10.2.2.2:5060 -> 10.4.4.4:5060 64702@0:1480 .......qINVITE sip:16179086547@10.4.4.4:5060 SIP/2.0. Record-Route: sip:16179086547@10.2.2.2;ftag=4167926089;lr=on. Via: SIP/2.0/UDP 10.2.2.2;branch=z9hG4bKa01f.bbf787d1.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com. Contact: sip:e2AyJyUQgCGf_Y06tu_rM3e-U3sthj-vO8pYWVWTJVaikNLrDMx5XcCCLEBXvjyirBs hBuEUU_feciI091Ig8MNh7KZJzeH1d4fC7EsItfCfsA5in1v1fKYFFWpWOtqrj@10.1.1.1 . Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. Proxy-Authorization: Digest username="6173164000",realm="sbc1.mydomain.com",nonce="4140d569a58f4230a 925f11b564c223a856b792a",response="e9a140cc3bad75e35c6a96449ff7cc41",uri ="sip:16179086547@sbc1.mydomain.com". Max-Forwards: 67. Content-Type: application/sdp. User-Agent: X-Lite release 1103m. Record-Route: sip:dd4f232@10.1.1.1;lr. Record-Route: sip:e7DlN09kmHaZbabZRm9W0bzJ0uoyUyFM0PVyKvgCloKvDqsLXMsCA6nvRkR8LsbRi@1 0.1.1.1;lr. Content-Length: 230. . v=0. o=6173164000 94360252 94360262 I # U 10.4.4.4:5060 -> 10.2.2.2:5060 SIP/2.0 100 Trying. Via: SIP/2.0/UDP 10.2.2.2;branch=z9hG4bKa01f.bbf787d1.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=as3b7f7d4e. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. User-Agent: Asterisk PBX. Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER. Contact: sip:16179086547@10.4.4.4. Content-Length: 0. .

# U 10.4.4.4:5060 -> 10.2.2.2:5060 SIP/2.0 183 Session Progress. Via: SIP/2.0/UDP 10.2.2.2;branch=z9hG4bKa01f.bbf787d1.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=as3b7f7d4e. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. User-Agent: Asterisk PBX. Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER. Contact: sip:16179086547@10.4.4.4. Content-Type: application/sdp. Content-Length: 259. . v=0. o=root 4025 4025 IN IP4 10.4.4.4. s=session. c=IN IP4 10.4.4.4. t=0 0. m=audio 19052 RTP/AVP 3 0 8 101. a=rtpmap:3 GSM/8000. a=rtpmap:0 PCMU/8000. a=rtpmap:8 PCMA/8000. a=rtpmap:101 telephone-event/8000. a=fmtp:101 0-16. a=silenceSupp:off - - - -.

# U 10.2.2.2:5060 -> 10.1.1.1:5060 SIP/2.0 183 Session Progress. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=as3b7f7d4e. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. User-Agent: Asterisk PBX. Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER. Contact: sip:16179086547@10.4.4.4. Content-Type: application/sdp. Content-Length: 259. . v=0. o=root 4025 4025 IN IP4 10.4.4.4. s=session. c=IN IP4 10.4.4.4. t=0 0. m=audio 19052 RTP/AVP 3 0 8 101. a=rtpmap:3 GSM/8000. a=rtpmap:0 PCMU/8000. a=rtpmap:8 PCMA/8000. a=rtpmap:101 telephone-event/8000. a=fmtp:101 0-16. a=silenceSupp:off - - - -.

#### U 10.4.4.4:5060 -> 10.2.2.2:5060 SIP/2.0 200 OK. Via: SIP/2.0/UDP 10.2.2.2;branch=z9hG4bKa01f.bbf787d1.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. Record-Route: sip:16179086547@10.2.2.2;ftag=4167926089;lr=on. Record-Route: sip:dd4f232@10.1.1.1;lr. Record-Route: sip:e7DlN09kmHaZbabZRm9W0bzJ0uoyUyFM0PVyKvgCloKvDqsLXMsCA6nvRkR8LsbRi@1 0.1.1.1;lr. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=as3b7f7d4e. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. User-Agent: Asterisk PBX. Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER. Contact: sip:16179086547@10.4.4.4. Content-Type: application/sdp. Content-Length: 259. . v=0. o=root 4025 4026 IN IP4 10.4.4.4. s=session. c=IN IP4 10.4.4.4. t=0 0. m=audio 19052 RTP/AVP 3 0 8 101. a=rtpmap:3 GSM/8000. a=rtpmap:0 PCMU/8000. a=rtpmap:8 PCMA/8000. a=rtpmap:101 telephone-event/8000. a=fmtp:101 0-16. a=silenceSupp:off - - - -.

# U 10.2.2.2:5060 -> 10.1.1.1:5060 SIP/2.0 200 OK. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branc h=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZY SyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2. Record-Route: sip:16179086547@10.2.2.2;ftag=4167926089;lr=on. Record-Route: sip:dd4f232@10.1.1.1;lr. Record-Route: sip:e7DlN09kmHaZbabZRm9W0bzJ0uoyUyFM0PVyKvgCloKvDqsLXMsCA6nvRkR8LsbRi@1 0.1.1.1;lr. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=as3b7f7d4e. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 INVITE. User-Agent: Asterisk PBX. Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER. Contact: sip:16179086547@10.4.4.4. Content-Type: application/sdp. Content-Length: 259. . v=0. o=root 4025 4026 IN IP4 10.4.4.4. s=session. c=IN IP4 10.4.4.4. t=0 0. m=audio 19052 RTP/AVP 3 0 8 101. a=rtpmap:3 GSM/8000. a=rtpmap:0 PCMU/8000. a=rtpmap:8 PCMA/8000. a=rtpmap:101 telephone-event/8000. a=fmtp:101 0-16. a=silenceSupp:off - - - -.

# U 10.1.1.1:5060 -> 10.2.2.2:5060 ACK sip:16179086547@10.4.4.4 SIP/2.0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;rport=35060;branc h=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;xdata=qDJF1BWCnmazyv84YkNW+wqO ln1crB-OMdLqm-1dScJ09UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=as3b7f7d4e. Contact: sip:e5oUfTi8xf2OqFiDy7UfeA7DqUjH00lIfqT4fsKAkukUTt1duZ_VPH2tfjJwa_F0yN4 ZoQcfeXYHJG2YatOPWrhtr0LX4ucrckG00r17249_sA5in1v1fKYFFWpWOtqrj@10.1.1.1 . Route: sip:16179086547@10.2.2.2;ftag=4167926089;lr=on. Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 ACK. Max-Forwards: 68. Content-Length: 0. .

# U 10.2.2.2:5060 -> 10.4.4.4:5060 ACK sip:16179086547@10.4.4.4 SIP/2.0. Record-Route: sip:16179086547@10.2.2.2;ftag=4167926089;lr=on. Via: SIP/2.0/UDP 10.2.2.2;branch=0. Via: SIP/2.0/UDP 10.1.1.1:5060;branch=z9hG4bK3fb33a2d10203ada0c7f7299b985c8f4.0. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK4afb43404e7c33130c7f7299b985c8f4.0;xdata=Ly0nkoyID 7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_. Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;rport=35060;branc h=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;xdata=qDJF1BWCnmazyv84YkNW+wqO ln1crB-OMdLqm-1dScJ09UTlKI5NKdRfAsMB1v-2. From: Test User sip:6173164000@sbc1.mydomain.com:35060;tag=4167926089. To: sip:16179086547@sbc1.mydomain.com;tag=as3b7f7d4e. Contact: sip:e5oUfTi8xf2OqFiDy7UfeA7DqUjH00lIfqT4fsKAkukUTt1duZ_VPH2tfjJwa_F0yN4 ZoQcfeXYHJG2YatOPWrhtr0LX4ucrckG00r17249_sA5in1v1fKYFFWpWOtqrj@10.1.1.1 . Call-ID: 537E6EED-0DCD-4DDF-AE66-EDCC8A95DC79@10.3.3.3. CSeq: 12667 ACK. Max-Forwards: 67. Content-Length: 0. .

After this ACK is relayed, the call setup is incomplete because asterisk has dropped the call.

__________________________________________ Salvatore Giudice 617-392-1689 617-392-8120 salvatore.giudice@fmr.com