Re: [reSIProcate] 200 OK for SUBSCRIBE
On Wed, 2005-11-30 at 10:53 -0600, Robert Sparks wrote:
> There's a lot of background that led to this design decision, and the
> code _is_ doing this on purpose.
>
> Here's an attempt to capture that background in a nutshell:
>
> Because proxies can only return one final response to a non-INVITE
> request, RFC3265 mandates an
> initial NOTIFY to each subscription. If a SUBSCRIBE forks, the
> NOTIFYs are the only way the subscribing
> client finds out about all the places the subscription was accepted.
> Further, even in the scenario where
> there is no forking, or even no proxies, the NOTIFY is enough to let
> you know the subscription has been
> created. So to unify the code, DUM only pays attention to the NOTIFYs
> for creating subscription usages.
> The 2xx to the SUBSCRIBE itself is ignored (it will always be
> redundant with the immediate NOTIFY from
> one branch).
And in many cases the NOTIFY will arrive first anyway...
--
Scott Lawrence tel:+1-781-938-5306;ext=162 or sip:slawrence@xxxxxxxxxxx
Consulting Engineer - Pingtel Corp. http://www.pingtel.com/
sipXpbx project coordinator - SIPfoundry http://www.sipfoundry.org/sipX