[Serusers] Problem with cancel a invite

[Marian Dumitru]

Hi Greger,

I know that the RFC doesn't specify if CANCEL is or not allows within 
the dialog - there were also some discussions on the sip-implementors 
mailing list about how to handle a CANCEL within the dialog.
Anyhow, IMHO, even if allowed, CANCEL within the dialog makes less sense 
- to be honest I saw no implementation doing something like this.

Now, back to the original subject: as Anders describe his problem, is 
definitely not the case of a within the dialog CANCEL and we should come 
up with some hints relevant to his case and avoid confusing the guy more 
  than necessary ;).

And regarding the t_relay() and CANCEL - there is no need to apply same 
RURI transformations as for INVITE - TM saves the INVITE outgoing RURI; 
when CANCEL comes, it is matched with an INVITE and the RURI for CANCEL 
is automatically taken from the INVITE transaction.

regards,
Marian

Greger V. Teigre wrote:
> Hi Marian!
> 
> Marian Dumitru wrote:
> 
>> CANCEL has nothing to do with loose route - and it will never hit he
>> loose route. The Route ser is set only when the dialog is established
>> (200 ok); and CANCEL happens *before* the dialog completion.
>>
>> The big idea with CANCEL is to take care to route it *exactly* as its
>> INVITE.
> 
> 
> AFAIK, CANCEL can happen both in-dialog and outside a dialog.  This was 
> a part of the verification we did when developing the ONsip.org 
> reference config filers. I'm not sure if the discussion was on serusers 
> or not, but as far as I remember, there is situation where CANCEL will 
> be in-dialog and thus can take the loose route path, i.e. reINVITEs.
> As you will see in the ONsip.org config files, CANCEL is handled as an 
> INVITE, but loose route test is done *before* the test on CANCEL to make 
> sure that any in-dialog CANCELs are handled properly.
> 
>> As a hint, if you use TM, t_relay() all the time will take care to
>> send the CANCEL to same destination as INVITE.
> 
> 
> ... as long as you have done the same r-uri transformations as with the 
> INVITE.
> g-)
> 
>> regards,
>> Marian
>>
>> Greger V. Teigre wrote:
>>
>>> Most likely you don't handle the CANCEL messages correctly. May be
>>> that you don't do proper loose route handling.  Take a look at the
>>> example configs (and the Getting Started document) at
>>> http://onsip.org/  You gain much be following the logic found there,
>>> they have been verified for all kinds of situations...
>>> g-)
>>>
>>> Anders Hansson wrote:
>>>
>>>> Hi all,
>>>> I´ve got a problem when trying to cancel an invite.
>>>> The situation: A makes a call to B (INVITE). B press the "hang up"
>>>> button. An here comes the problem.
>>>> From As side, everything is OK, but from Bs side, the phone is still
>>>> ringing...
>>>> How can a solve this problem? Anyone?
>>>>
>>>> Thanks,
>>>> Anders 
> 
> 
> 

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