[OpenSIPS-Users] Dialog module and uac_auth

[opensipslist at encambio.com]

Hello Bogdan,

An jeu., déc 24, 2009, Bogdan-Andrei Iancu schrieb:
>opensipslist at encambio.com wrote:
>> A while ago it was clear that uac_auth is of limited utility,
>> due to the SIP RFC which requires that each message has a unique
>> cseq. Calling uac_auth from failure_route produced a new INVITE
>> with a proxy-auth header that didn't have a new cseq however.
>>
>> Since the dialog module appeared, I'm wondering how if scripts
>> can be tweaked to use uac_auth in a SIP RFC compliant way.
>>
>> ...or is it still true that doing uac_auth() in failure_route
>> fills in the proxy-auth header of a INVITE message that has
>> already expired its cseq (no longer valid in the dialog)?
>>
>The limitation is still true - even with the dialog support, the
>dialog can be monitored, but not changed - changing the CSEQ will
>affect the dialog for its whole lifetime , requiring opensips to
>constantly update the cseq in all sequential requests....this is
>more than the dialog module was designed for :)
>
So I suppose you're saying that the only way to use uac_auth is
to send two INVITEs, one without auth credentials followed by
on with the proper auth credentials... but without an increased
cseq number.

For what is that valuable at all (I thought that OpenSIPS tries
to be as RFC compliant as possible?) I have the feeling that I'm
not 'getting it' or using uac_correctly, in a way that the cseq
numbers are not relevant.

I'm trying to authenticate a UAC phone with a third party SIP to
PSTN gateway, while having OpenSIPS in between. The gateway rejects
repeated INVITEs with the same cseq number. The situation is quite
typical, so I'm sure that OpenSIPS provides a way to solve this
problem, no?

>> How can uac_auth be used with INVITE messages in a SIP RFC
>> compliant way?
>>
Any ideas or is this frequent situation really impossible to handle?

Regards,
Brian