[SR-Users] t_relay_cancel usage

[Jan Janak]

Juha,

On Thu, Oct 7, 2010 at 8:52 AM, Juha Heinanen <jh at tutpro.com> wrote:
> Andrei Pelinescu-Onciul writes:
>
>> > if proxy is processing all invites statefully, why anything needs to be
>> > done when invite transaction corresponding the to cancel is missing?
>> > isn't it a case of unmatched cancel and the cancel could just be
>> > dropped?
>>
>> Well, IMHO it should be forwarded the same as one would forward the
>> INVITE. Dropping it is quite a hardliner approach :-)
>
> andrei,
>
> i would challenge invite, but can't do that for cancel.  what is the
> advantage of becoming an open unmatched cancel relay?

Maybe for reliability reasons? If something goes wrong with your proxy
and it looses the state for a transaction, the proxy might just
forward the request statelessly and hope for the best. I know there
are many cases where this would not work (serial forking, etc.) in
real world setups, but I guess we have just been trying to be as
forgiving as possible in such cases.

-Jan