[OpenSIPS-Devel] [B2B_ENTITIES] Difference between sending CANCEL and BYE

[Anca Vamanu]

Hi Olivier,

Olivier Détour wrote:
> 2010/1/22 Olivier Détour <chino540off+kamailio at gmail.com>:
>   
>> Hi,
>>
>> I understand the problem, but I would like to explain you my topology:
>>
>>                      Broker1             Broker2
>>                          |                       |
>> Tel(10) ---------- B2BUA1 ---------- B2BUA2 ---------- Tel(20)
>>
>> My problem is when 10 calls 20, 20 is ringing (so B2BUAs create their
>> UAS and UAC).
>> I want to be able to brake the current SIP session at this moment.
>> So I send the CANCEL to UAC side on B2BUA1. But B2BUA2 doesn't want to
>> receive it,
>> because It is not send to sip:sa at 1.1.12.3. So message could not be
>> transmit to B2BUA2 ...
>>
>> Maybe, I don't understand something here, but b2b_entities API could
>> be able to manage
>> this situation ?
>>
>> Regards,
>>
>>     
>
> Hi,
>
> I went through the source code of B2B_entities, and I don't understand
> when you search the dlg in int b2b_prescript_f(struct sip_msg *msg,
> void *uparam) in dlg.c:
>
>   357 		while(dlg)
>   358 		{
>   359 			if(ruri.len == dlg->ruri.len && strncmp(ruri.s, dlg->ruri.s,
> ruri.len)== 0
>   360 					&& dlg->callid.len == callid.len &&
>   361 					strncmp(dlg->callid.s, callid.s, callid.len)== 0 &&
>   362 					dlg->tag[CALLER_LEG].len == from_tag.len &&
>   363 					strncmp(dlg->tag[CALLER_LEG].s, from_tag.s, from_tag.len)== 0)
>
> You check CALLID, FROM_TAG and the REQUEST_URI. If you create the UAS
> with B2BUA_entities,
> Requests send by caller will change Request URI to speaks directly with UAS.
>
> Why is the RURI in your search?
>
> When I remove the RURI check, it works as my understanding of the RFC.
>
> Regards,
>
>   
The RURI check was added exactly because the RFC says that the RURI in 
CANCEL must be exactly the same as the RURI in INVITE:

The following procedures are used to construct a CANCEL request.  The
   Request-URI, Call-ID, To, the numeric part of CSeq, and From header
   fields in the CANCEL request MUST be identical to those in the
   request being cancelled, including tags.


Regards,

-- 
Anca Vamanu
www.voice-system.ro