2012/8/17 Juha Heinanen jh@tutpro.com:
regarding this:
Sure but, how to distinguish the *first* in-dialog NOTIFY and any other later? No way.
i would imagine that presence server does know when subscription is created and first notify is sent.
Sure.
and of course one would use this feature only when sip proxy and presence server are both based on kamailio run by the same service provider.
So you suggest the presence module to insert a custom header/param in the first NOTIFY of a subscription just to avoid the intermediary proxi(es) to do record-routing, but at the same time all the default script files for SER in sip-router sources call record_route() for *every* requests (initial and in-dialog). And you really want to avoid something that both RFC 3265 and 6665 suggest (adding RR for *every* NOTIFY).
Honestly, I think adding the "feature" you propose is a waste of time and a not needed complexity. The custom header check could be, probably, more expensive than just adding RR to every NOTIFY.
regarding obsoleted rfc, i don't see a big need to support it. if rr missing from notifys would be a big problem, kamailio users would already have noticed it.
The problem takes place when a RFC 6665 strict compliant UAC expects to create the dialog with the Record-Route headers retrieved from the first NOTIFY. Taking into acount that this requirement appears in RFC 6665 which has been published in July 2012, I expect that no one existing UAC will suffer it (but maybe new devices do). So Kamailio users cannot noticed this problem (yet).
Regards.