Re: [Sipping] I-D ACTION:draft-ietf-sipping-dialogusage-02.txt

[Paul Kyzivat <pkyzivat at cisco.com>]

Christer Holmberg (JO/LMF) wrote:
> Hi Robert,
>
> I will reply on your previuos mail later, but one issue I forgot to mention (I think I raised this issue on the list a while ago also).
>
> TENTH: How are early dialogs affected? Assume a client initiates a invite usage, and receives 18x responses from multiple locations. Then, the client will create subscribe usages on some of these early dialogs.
>
> Then, when 200 is received for the INVITE on one dialog, what happens to the other dialogs? Normally they would be terminated, but now we have created subscribe usages on them...
>
> I think the easiest solution for this would be to say that multiple dialog usages are only allowed on fully established dialogs.

Why is there even an issue here?

In reality it isn't the dialog that is early - its the invite dialog 
usage that is early. (You shouldn't get early dialogs from other dialog 
establishing requests.)

The establishment of an early invite dialog usage results in creating a 
dialog (not an early dialog), that has one usage. Like always, the 
dialog goes away when all the usages do.

Making a rule that you can reuse a dialog with an early invite dialog 
usage is just an arbitrary added rule. It doesn't seem to simplify 
anything. Also, I'm not sure, but aren't there blind transfer scenarios 
that might actually use this? (REFER in an dialog with an early invite.)

	Paul

_______________________________________________
Sipping mailing list  https://www1.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