[SR-Users] Dialogue restore after initial processing

[Joao Alves]

Hi Daniel,

If I remember correctly the To-tag would be needed prior to 200 OK do to "early dialogs". Which in a way is supported by the 180 Ringing where the To-tag was self-generated by kamailio when building the response.

So I was not sure was a "bug" not updating the $tt accordingly or, whether there would be a need for a new function dlg_get_early(callid, ftag) as you suggested.

But both would work for me. If this could be done, appreciated:)

Many Thanks,
Joao

From: Daniel-Constantin Mierla [mailto:miconda at gmail.com]
Sent: quinta-feira, 16 de Julho de 2015 10:38
To: Kamailio (SER) - Users Mailing List; Joao Alves
Subject: Re: [SR-Users] Dialogue restore after initial processing

Hello,

iirc, the to-tag is set in the dialog structure when the 200ok is processed. During the call setup, there can be many outgoing branches, therefore many 'early' to-tags, but only one will be final, once the call is answered.

On the other hand, there is a C function that returns the local generated To-tag. It is in sl module, named get_reply_totag(...). It is not available in the config file, not being needed so far.

Anyhow, in your case, might be better to add a function dlg_get_early(callid, ftag), because to-tag of the dialog is not really known at that moment.

Cheers,
Daniel
On 14/07/15 17:14, Joao Alves wrote:
Hi,

I'm trying to restore a SIP session dialogue context and  found dlg_get(callid, ftag, ttag) function for that.

However, I cannot access the To tag. I noticed on the 180 RINGING there was already an self-generated included on this response, but I also could not access its value.

When receiving the SIP INVITE request I used the dlg_manage() and the context was initially stored.

if(is_known_dlg()) {
                xlog("Request $rm from $ci is in-dialog\n");
                xlog(">>From tag is $ft and To tag is $tt\n");

                # Needed to later restore the dialog
                $shv(ftag)=$ft;
                $shv(ttag)=$tt;
        }

15(49100) ERROR: <script>: Request INVITE from 76589ZWQ5NzIyYjMzNDI1YjVjM2E5ZWU5NjhkYzEyNjE3MzQ is in-dialog
15(49100) exec: *** cfgtrace:request_route=[MATRIX] c=[/etc/kamailio/kamailio.cfg] l=1021 a=25 n=xlog
15(49100) DEBUG: pv [pv_core.c:376]: pv_get_xto_attr(): no Tag parameter
15(49100) ERROR: <script>: >>From tag is 8fd06474 and To tag is <null>

Since there was a self-generated one (after the 180 RINGING being sent), I rechecked the $tt and $dlg(to_tag) values and both still returned null values.

15(49100) DEBUG: tm [t_lookup.c:1083]: t_check_msg(): DEBUG: t_check_msg: T already found!
15(49100) DEBUG: <core> [tcp_main.c:2196]: tcpconn_send_put(): send from reader (49100 (15)), reusing fd
15(49100) DEBUG: <core> [tcp_main.c:2430]: tcpconn_do_send(): sending...
15(49100) DEBUG: <core> [tcp_main.c:2464]: tcpconn_do_send(): after real write: c= 0x7effdf7da860 n=396 fd=5
15(49100) DEBUG: <core> [tcp_main.c:2465]: tcpconn_do_send(): buf=
SIP/2.0 180 ringing
Via: SIP/2.0/TCP 192.168.1.5:58751;branch=z9hG4bK-524287-1---a64e0a42199ee419;rport=61134;received=85.138.200.8
To: <sip:1001 at decasa.website><sip:1001 at decasa.website>;tag=a6a1c5f60faecf035a1ae5b6e96e979a-f6a3
From: "1000"<sip:1000 at decasa.website><sip:1000 at decasa.website>;tag=8fd06474
Call-ID: 76589ZWQ5NzIyYjMzNDI1YjVjM2E5ZWU5NjhkYzEyNjE3MzQ
CSeq: 1 INVITE
Server: kamailio (4.3.0 (x86_64/linux))
Content-Length: 0


..., shmem=0x7effdf7e1e00: SIP/2.0 180 ringingght(): DEBUG: reply sent out. buf=0x7effec023bf8: SIP/2.0 180 ringing
15(49100) DEBUG: tm [t_reply.c:657]: _reply_light(): DEBUG: _reply_light: finished
15(49100) DEBUG: sl [sl.c:272]: send_reply(): reply in stateful mode (tm)
15(49100) exec: *** cfgtrace:request_route=[MATRIX] c=[/etc/kamailio/kamailio.cfg] l=1031 a=25 n=xlog
15(49100) DEBUG: dialog [dlg_hash.c:640]: dlg_lookup(): ref dlg 0x7effdf7e1bf0 with 1 -> 2
15(49100) DEBUG: dialog [dlg_hash.c:642]: dlg_lookup(): dialog id=5769 found on entry 128
15(49100) DEBUG: dialog [dlg_hash.c:858]: dlg_unref(): unref dlg 0x7effdf7e1bf0 with 1 -> 1
15(49100) ERROR: <script>: Dialog To Tag: <null>                                                                                                   <== xlog("Dialog To Tag: $dlg(to_tag)\n");
15(49100) exec: *** cfgtrace:request_route=[MATRIX] c=[/etc/kamailio/kamailio.cfg] l=1033 a=25 n=xlog
15(49100) DEBUG: pv [pv_core.c:376]: pv_get_xto_attr(): no Tag parameter
15(49100) ERROR: <script>: >>From2 tag is 8fd06474 and To tag is <null>

Many thanks,

Joao Alves
Solution Architect, Unified Communications


This message and the information contained herein is proprietary and confidential and subject to the Amdocs policy statement, you may review at http://www.amdocs.com/email_disclaimer.asp



_______________________________________________

SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list

sr-users at lists.sip-router.org<mailto:sr-users at lists.sip-router.org>

http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users



--

Daniel-Constantin Mierla

http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda

Book: SIP Routing With Kamailio - http://www.asipto.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sip-router.org/pipermail/sr-users/attachments/20150717/3e100002/attachment.html>