Re: Comment on DERIVE and B2BUAs

Dean Willis wrote:
>
> On Oct 28, 2008, at 11:05 PM, Dan Wing wrote:
>>>
>>> Would the SBC not have to handle the SUBSCRIBE request locally? After
>>> all, since it is a terminal UA for the call, it also knows
>>> about all the
>>> dialog states. The end-user UA would never even see the SUBSCRIBE.
>>
>> If that's a problem, just use some different method that goes end to
>> end.  The always-loved INFO comes to mind.
>
> What makes you think that INFO goes end to end? An SBC can absorb it 
> if it wants to.

And, in any case, you can't send an INFO out of dialog. So you can't 
route it to the address in the From -- all you can do is route it back 
along the dialog path. And, of course, *that's* going to work. If it's a 
legitimate call, you'll reach the legitimate caller, who will confirm 
the call is legitimate. If it's a forged call, you'll reach the 
attacker, who will confirm the call is legitimate.

/a
_______________________________________________
Sip mailing list  https://www.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email protected] for questions on current sip
Use [email protected] for new developments on the application of sip