[Serdev] Re: Handling of early CANCELs - was Re: [Serusers] SER Nokia CANCEL Problem

[Bogdan Pintea]

Andrei Pelinescu-Onciul wrote:
> On Feb 26, 2007 at 17:45, Martin Hoffmann <hn at nvnc.de> wrote:
>   
>> Which makes it all the more apparent that t_relay() should never relay a
>> CANCEL. Ever. It should return with an error and I then can decide
>> whether I have a stateless proxy or not to statelessly forward the
>> CANCEL or just error it away.
>>     
>
> I think it should relay the CANCEL and if an INVITE comes and the CANCEL
> transaction is still alive, it should reply w/ 487 (Ottendorf does
> this).
>   

But isn't there a potential for DOS? Since CANCELs can only be accepted 
(no auth*), sending CANCELs to nowhere (from anonymous.invalid :) ) 
seems the easiest solution to eat fast the shm.

Bogdan.

>
> Andrei
>   

-- 
Bogdan Pintea

iptego GmbH  -  VoIP Security
http://www.iptego.de