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+mWJLaKZXFCdTMwK3YcFmw9BXXO0mZ-oXaK-fZQ_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;rport=35060;branch=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;xdata=8BnRlTLlFQxaEMygbWSMP79KbMGMDOh+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@10.1.1.1;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+mWJLaKZXFCdTMwK3YcFmw9BXXO0mZ-oXaK-fZQ_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;rport=35060;branch=z9hG4bKA3614A811BC64CCB8E74944E08E28F13;xdata=8BnRlTLlFQxaEMygbWSMP79KbMGMDOh+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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2.
From: Test User <sip:6173164000@sbc1.mydomain.com:35060>;tag=4167926089.
To: <sip:16179086547@sbc1.mydomain.com>.
Contact: <sip:e2AyJyUQgCGf_Y06tu_rM3e-U3sthj-vO8pYWVWTJVaikNLrDMx5XcCCLEBXvjyirBshBuEUU_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="4140d569a58f4230a925f11b564c223a856b792a",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@10.1.1.1;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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2.
From: Test User <sip:6173164000@sbc1.mydomain.com:35060>;tag=4167926089.
To: <sip:16179086547@sbc1.mydomain.com>.
Contact: <sip:e2AyJyUQgCGf_Y06tu_rM3e-U3sthj-vO8pYWVWTJVaikNLrDMx5XcCCLEBXvjyirBshBuEUU_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="4140d569a58f4230a925f11b564c223a856b792a",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@10.1.1.1;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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-2.
From: Test User <sip:6173164000@sbc1.mydomain.com:35060>;tag=4167926089.
To: <sip:16179086547@sbc1.mydomain.com>.
Contact: <sip:e2AyJyUQgCGf_Y06tu_rM3e-U3sthj-vO8pYWVWTJVaikNLrDMx5XcCCLEBXvjyirBshBuEUU_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="4140d569a58f4230a925f11b564c223a856b792a",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@10.1.1.1;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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-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@10.1.1.1;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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK080E9671A10348788D72788ABB32E000;rport=35060;branch=z9hG4bK080E9671A10348788D72788ABB32E000;xdata=g8U1gLW+1SbzScgzuAlduOZYSyicHJNYp0Htso2oJc909UTlKI5NKdRfAsMB1v-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@10.1.1.1;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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;rport=35060;branch=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;xdata=qDJF1BWCnmazyv84YkNW+wqOln1crB-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_F0yN4ZoQcfeXYHJG2YatOPWrhtr0LX4ucrckG00r17249_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=Ly0nkoyID7sZ1hOYXRKnV3gFIgkEphTIhD00WmRnWSo_.
Via: SIP/2.0/UDP 0.0.0.0;branch=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;rport=35060;branch=z9hG4bK8A5B0DBACBFA421DBE4F707FA2084744;xdata=qDJF1BWCnmazyv84YkNW+wqOln1crB-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_F0yN4ZoQcfeXYHJG2YatOPWrhtr0LX4ucrckG00r17249_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