[OpenSIPS-Users] Issue with 'To' tag and t_reply

Thu Mar 26 14:02:21 EST 2020

Hi,
As per my original email:
1. I was doing exactly as you suggested, in failure_route I'm using
t_reply("404","Not Found") and it comes out with a wrong To: tag.
2. I don't need to proxy response from server B, I need to analyze its
response and send a response to server A according to my needs.

Currently it seems that t_reply is not using same To tag if 183 Session
Progress has been proxied, which is strange as I have dialog running.

Regards,
Yury.

чт, 26 мар. 2020 г. в 19:13, Yury Kirsanov <y.kirsanov at gmail.com>:

> Hi,
> I'm using an OpenSIPS as a proxy between two servers. First one is sending
> SIP INVITE to OpenSIPS, then OpenSIPS forwards request to second server.
> I'm creating a dialog on initial INVITE. Second server then replies with
> SIP 183 Session Progress, plays back a message and then responds with 4XX
> code, for example SIP 404 Not Found (indicating that number dialed is
> disconnected). In OpenSIPS I'm receiving that reply and in failure_route
> I'd like to change that code to a bit different SIP 404, so I'm using
> following code:
>
> append_to_reply("Reason: Q.850;cause=1");
> t_reply("404","Not Found");
> exit;
>
> But in this case I can see that OpenSIPS generates additional branch (???
> not sure here) with different "To" tag and pushes it out and then forwards
> original reply SIP packet even though I have an exit statement in my
> failure_route. I tried to do sl_send_reply and behavior is pretty much the
> same. Can someone let me know what I may be doing wrong? I need correct
> "To" tag to be used (based on 183 Session Progress message from server B
> and passed to server A previously) and second 404 shouldn't be forwarded
> out.
>
> Here's an example of a call with my explanations
>
> Initial invite from server A, no 'to tag' as expected:
>
> INVITE sip:XXXXXXXXX at B.B.B.B SIP/2.0
> Max-Forwards: 67
> To: "XXXXXXXXX" <sip:XXXXXXXXX at B.B.B.B>
> Call-ID: 469A5568-E092-4038-B1B8-13AC9B9571CA
> Via: SIP/2.0/UDP A.A.A.A:5060;rport;branch=z9hG4bK773616538
> From: "YYYYYYYYY" <sip:YYYYYYYYY at A.A.A.A>;tag=117583367
> CSeq: 1741310 INVITE
> User-Agent: User Agent
> Contact: <sip:YYYYYYYYY at A.A.A.A:5060>
> Allow: ACK, INVITE, BYE, CANCEL, REGISTER, REFER, OPTIONS, INFO,
> SUBSCRIBE, NOTIFY
> Date: Thu, 26 Mar 2020 07:54:55 GMT
> Content-Type: application/sdp
> Content-Length: 250
>
> v=0
> o=dcom 1585209295 1585209295 IN IP4 A.A.A.A
> s=SIP Call
> c=IN IP4 A.A.A.A
> t=0 0
> m=audio 15340 RTP/AVP 8 0 18 101
> a=rtpmap:8 PCMA/8000
> a=rtpmap:0 PCMU/8000
> a=rtpmap:18 G729/8000
> a=fmtp:18 annexb=no
> a=rtpmap:101 telephone-event/8000
>
> Response from OpenSIPS:
>
> SIP/2.0 100 Giving a try
> To: "XXXXXXXXX" <sip:XXXXXXXXX at B.B.B.B>
> Call-ID: 469A5568-E092-4038-B1B8-13AC9B9571CA
> Via: SIP/2.0/UDP
> A.A.A.A:5060;received=A.A.A.A;rport=5060;branch=z9hG4bK773616538
> From: "YYYYYYYYY" <sip:YYYYYYYYY at A.A.A.A>;tag=117583367
> CSeq: 1741310 INVITE
> Server: Server Signature
> Content-Length: 0
>
> OpenSIPS has forwarded packet to Server B and Server B responded with 183
> and assigned a 'To' tag:
>
> SIP/2.0 183 Session Progress
> Via: SIP/2.0/UDP
> A.A.A.A:5060;received=A.A.A.A;rport=5060;branch=z9hG4bK773616538
> Call-ID: 469A5568-E092-4038-B1B8-13AC9B9571CA
> From: "YYYYYYYYY" <sip:YYYYYYYYY at A.A.A.A>;tag=117583367
> To: "XXXXXXXXX" <sip:XXXXXXXXX at B.B.B.B>;
> *tag=0b49dc32-2c4b-413e-a349-c781a23d53b9*
> CSeq: 1741310 INVITE
> Server: PBX
> Contact: <sip:B.B.B.B;did=d0a.99678f73>
> Allow: OPTIONS, REGISTER, SUBSCRIBE, NOTIFY, PUBLISH, INVITE, ACK, BYE,
> CANCEL, UPDATE, PRACK, REFER
> Content-Type: application/sdp
> Content-Length: 354
>
> v=0
> o=- 1585209295 1585209297 IN IP4 B.B.B.B
> s=Asterisk
> c=IN IP4 B.B.B.B
> t=0 0
> a=rtpengine:673f999268ae
> m=audio 32386 RTP/AVP 0 8 18 101
> a=maxptime:150
> a=rtpmap:0 PCMU/8000
> a=rtpmap:8 PCMA/8000
> a=rtpmap:18 G729/8000
> a=rtpmap:101 telephone-event/8000
> a=fmtp:18 annexb=no
> a=fmtp:101 0-16
> a=sendrecv
> a=rtcp:32387
> a=ptime:20
>
> Server B responds with SIP 404 after playing back message that number is
> disconnected and I'm trying to reply to server A with custom Reason
> message. To_tag is completely different from the To tag that has been
> passed to server A after initial 183!!!
>
> SIP/2.0 404 Not Found
> To: "XXXXXXXXX" <sip:XXXXXXXXX at B.B.B.B>;
> *tag=a976.21514595b467be41a9b712a6b0b621d9*
> Call-ID: 469A5568-E092-4038-B1B8-13AC9B9571CA
> Via: SIP/2.0/UDP
> A.A.A.A:5060;received=A.A.A.A;rport=5060;branch=z9hG4bK773616538
> From: "YYYYYYYYY" <sip:YYYYYYYYY at A.A.A.A>;tag=117583367
> CSeq: 1741310 INVITE
> Reason: Q.850;cause=1;text="Number is disconnected"
> Server: Server Signature
> Content-Length: 0
>
> Of course, server A just ignores this message as it can't match 'To' tag
> to its transaction. Now, for some reason, OpenSIPS forwards original reply
> from Server B to Server A with the same 'To' tag as in 183 Session Progress:
>
> SIP/2.0 404 Not Found
> Via: SIP/2.0/UDP
> A.A.A.A:5060;received=A.A.A.A;rport=5060;branch=z9hG4bK773616538
> Call-ID: 469A5568-E092-4038-B1B8-13AC9B9571CA
> From: "YYYYYYYYY" <sip:YYYYYYYYY at A.A.A.A>;tag=117583367
> To: "XXXXXXXXX" <sip:XXXXXXXXX at B.B.B.B>;
> *tag=0b49dc32-2c4b-413e-a349-c781a23d53b9*
> CSeq: 1741310 INVITE
> Server: PBX
> Allow: OPTIONS, REGISTER, SUBSCRIBE, NOTIFY, PUBLISH, INVITE, ACK, BYE,
> CANCEL, UPDATE, PRACK, REFER
> Reason: Q.850;cause=1
> Content-Length:  0
>
> And at this point Server A can match this reply and responds with an ACK:
>
> ACK sip:XXXXXXXXX at B.B.B.B SIP/2.0
> Via: SIP/2.0/UDP A.A.A.A:5060;rport;branch=z9hG4bK773616538
> From: "YYYYYYYYY" <sip:YYYYYYYYY at A.A.A.A>;tag=117583367
> To: "XXXXXXXXX" <sip:XXXXXXXXX at B.B.B.B>;
> *tag=0b49dc32-2c4b-413e-a349-c781a23d53b9*
> Call-ID: 469A5568-E092-4038-B1B8-13AC9B9571CA
> CSeq: 1741310 ACK
> Max-Forwards: 67
> Contact: <sip:YYYYYYYYY at A.A.A.A:5060>
> User-Agent: User Agent
> Content-Length: 0
>
> I think that t_reply is creating a new transaction instead of using
> existing one, but I'm not sure why and how to fix this?
>
> Thanks!
>
> Best regards,
> Yury.
>
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