[OpenSIPS-Users] Ways of manipulating the From header of CANCEL

[Ricardo Martins]

Hi Bogdan! There is attached a log with debug 6 of the call. There you 
can see the opensips using the original from to build the cancel message 
before transmiting to the provider. And lots of retransmissions without 
a response from the provider.

The environment is quite simple: The opensips is running on a machine 
with  two network interfaces. It receives the INVITE by the private 
network interface (192.168.200.246) and send it to a ppp0 interface with 
a fixed and public ip.

For privacy reasons, I made the replacement of the public ip that 
appears on log and trace, using xxx.xxx.xxx.xxx instead. The original 
user at domain of the call is tronco2 at pabx1 and, after replacement, 
617056557 at nheen.net.br.

Thanks for your help. I think that there is something  tricky on my 
environment that is making this cancel to skip working "automagicaly".

Regards! Ricardo.





Bogdan-Andrei Iancu escreveu:
> Hi Ricardo,
>
>
> Ricardo Martins wrote:
>> Guys, I've been reading a lot on the list and testing on our servers 
>> (opensips 1.5) for some time but I still have a big issue!
>>
>> 1) If I use uac_replace_from on REQUEST route, the from header got 
>> miswritten (truncates) when using it twice. Bad for me, when intended 
>> to use it to provide backup routes on a call failure. But...
>>   
> yes, because the function can be called only once per branch - the 
> correct approach is the 2)
>> 2) When I use uac_replace_from on BRANCH route, the replacement works 
>> realy fine. In order to use a backup provider, I just arm the 
>> branch_route and, on branch route, execute uac_replace_from with the 
>> proper username/domain for that specific provider. The result is ok. 
>> The from header is properly rewriten, many times I need at the same 
>> transaction. But...
>>   
> so, no problems here, right ?
>> 3) When opensips receives a CANCEL, it do not rewrite the from 
>> header, prior to send it to the provider. Neither using the 
>> uac_replace_from function, neither using subst function (from 
>> textops). I read that CANCEL is locally generated, and that's why 
>> those funcions do not affect it. I read too that the uac_replace_from 
>> used on INVITE was expected to work on CANCELs automaticaly. But 
>> apears to not work when using uac_replace_from on BRANCH routes. And 
>> I tryied it with from_restore_mode parameter on 'manual' and on 
>> 'auto' mode.
>>   
> indeed, the CANCEL is internally generated, so whatever changes you do 
> for the received CANCEL in script are useless. But TM does 
> automagically update the FROM hdr in CANCELS (if the INVITE FROM was 
> changes), in any mode... If this does not happen, please post traces 
> and debug=6 logs for the call.
>
>> 4) Thats why I got a big of an issue! I MUST use the uac_replace_from 
>> on BRANCH routes to work with backup providers. And I MUST replace 
>> the from hdr of CANCEL, as my providers are rejecting CANCELs with 
>> diferent from headers!
>>   
> you do not have to deal with the CANCELs - they automatically done.. 
> see 3)
>> Do anybody could put this kind of environment to work? Have any clue 
>> about it?
>>   
>
> see 3), about traces and logs..
>
> Regards,
> Bogdan
>> Regards!
>>
>> Ricardo.
>>
>>
>>
>> _______________________________________________
>> Users mailing list
>> Users at lists.opensips.org
>> http://lists.opensips.org/cgi-bin/mailman/listinfo/users
>>
>>   
>
>

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