[Sipping-tispan] Voicemail-uri draft

Hi cullen,

It seems that in Vancouver, IETF people wanted to use the voicemail-draft for the Call Diversion simulation service. 

There are both technical and non-technical issues that need to be raised at this point. From a non technical point of view TISPAN needs to have a solution for Call Diversion in time for Release 1 (this means we need something in time for the end of the month).

>From a technical point of view this draft is currently does not meet Call Diversion requirements (and not only because of PSTN interoperability).

1/ The draft does not address redirecting number which is mandatory requirement for TISPAN (if IETF won't consider billing, TISPAN will be forced to define a P-header for this purpose)

2/ The draft assumes the SIP responses code are fit for providing Call Diversion reason. We believe that this is not true and seems more like a trick than a proper standard solution. I would recommend to use explicite reason values based on ITU-T Q.733 as done in a number of other drafts.

3/ The draft assumes that there is "no call leg between B and C". If this is the case, then this draft is not fit for Call Diversion simulation service because this is how Call Diversion works whether IETF like it or not. 

4/ Privacy of the forwarding leg is not addressed.

5/ The scope of the draft should be made broader the "voicemail", the voicemail application is one example application that benefits from a Cal Diversion service

Will the new version of the voicemail-draft will address all these issues in time for our needs ? 

Thanks,

Sébastien Garcin
France Télécom R&D