[OpenSIPS-Users] Delete alias references in SIP messages

Guillaume Lacroix gl at worldline.fr
Wed Aug 13 14:04:53 CEST 2008


Hi Bogdan,

Thanks for the hints. Here is the stuff : we would like to give premimum 
numbers (08XX...) to some of our customers.

These premium numbers are provided by an external carrier A. This 
carrier translate the number to one geographical number we choose. This 
geographical number will be an alias of a SIP account.

So : Regular phone in the PSTN -> 08XX (carrier A) -> 01XX (us - 
customer 1) -> SIP account (us - customer 1)

The problem is that the carrier A doesn't give any information that the 
regular phone has dialed the 08XX number (it is just like the regular 
phone dialed the 01XX directly). So, just by tracing the SIP messages, 
the customer 1 could easy know the translated number.

Since we can give some payback on incoming trafic for these numbers, we 
would like to avoid that (so, except carrier 1 and us, no one has to 
know this translated 01XX number). So the best would be to be able to 
modify any reference in SIP messages of the 01XX number to 08XX number 
(so that we can keep a trace that the number dialed should have been 08XX).

Thanks and regards,
Guillaume

Bogdan-Andrei Iancu a écrit :
> Hi Guillaume,
> 
> Changing TO header is more or less against the RFC3261 and you should 
> not do it. More or less the same discussion as for the FROM header.
> 
> Even if in openSIPS you can change the FROM without violating the RFC 
> (doing and undoing the change for all the sequential request inside the 
> dialog), for TO there is no such mechanism.
> 
> Why is so critical to remove it from the alias from the TO header ? 
> Understanding the cause may help me to give you some ideas ;)
> 
> Regards,
> Bogdan
> 
> Guillaume Lacroix wrote:
>> Hello,
>>
>> I would like to know if there an easy way to remove any reference to 
>> the SIP alias in the SIP messages for some incoming calls and to 
>> replace them with the SIP username.
>>
>> Roughly, a user dial the number 012345 from the PSTN. The call goes to 
>> a PSTN GW and is then sent to OpenSER through an INVITE message 
>> (INVITE 012345 at domain...). The To header also contains 012345 at domain. 
>> After the look up in the alias DB, the alias is replace by the SIP 
>> username, but it remains in the To header field.
>>
>> What I would like to do is to remove completely the alias reference 
>> and replace it with the username, not only in the INVITE but also in 
>> any following messages (so that the messages received by the UA never 
>> contains any reference to the alias) I try to use append_hf/remove_hf 
>> on the To header, it works, but the alias still appears in some other 
>> messages (ACK..).
>>
>> Does anyone know if there is a way to achieve that (not for all 
>> incoming number but only the number starting with 0123 for example) ?
>>
>> Thanks and regards,
>> Guillaume
>>
>> _______________________________________________
>> Users mailing list
>> Users at lists.opensips.org
>> http://lists.opensips.org/cgi-bin/mailman/listinfo/users
>>
>>   
> 
> 



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