Re: [Sipping] Liaison Statement on offer/answer procedures

["Elwell, John" <john.elwell at siemens.com>]

Paul,


> -----Original Message-----
> From: sipping-bounces at ietf.org 
> [mailto:sipping-bounces at ietf.org] On Behalf Of Paul Kyzivat
> Sent: 15 May 2008 14:48
> To: Christer Holmberg
> Cc: sipping List
> Subject: Re: [Sipping] Liaison Statement on offer/answer procedures
> 
> Christer,
> 
> Saying "you shouldn't do it" to changing contact address or media 
> address ignores facts of life that may require doing it. This 
> overlaps 
> strongly with the session mobility discussion that is 
> currently going on.
> 
> Specifically, if a UA is losing possession of its address, or 
> connectivity via that address, then it will have to do 
> *something*. If 
> we are going to say that you shouldn't change the contact 
> address in a 
> dialog, and shouldn't change the media address in a media 
> session, then 
> we need to specify some alternative.
> 
> Clearly there are at least two distinct cases here:
> 
> - there is a desire to switch to a new address, but the old address
>    can continue to be supported until and unless use of the new one
>    can be established
[JRE] So if the contact address changes and we successfully conclude the
UPDATE transaction, and then the old contact address disappears, it is
likely that the Via list on the re-INVITE request will have become
invalidated too, so the final response will not reach the UAC. Correct?

John
_______________________________________________
Sipping mailing list  https://www.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use sip-implementors at cs.columbia.edu for questions on current sip
Use sip at ietf.org for new developments of core SIP