Hi,
 
>>There are already problems which 199 CAN solve, without any 
>>other work.
>
>And those are?
>
>They should be clearly described. All I hear is examples of things where
>199 is not sufficient (e.g., Media choosing, HERFP). 

I have tried to describe examples not related to media choosing.

One example is related to in-band procedures (e.g. ICE, in-band security 
negotiations). At least in the mobile world those can consume radio- and 
battery resources, so it is good to be informed about terminated dialogs as 
soon as possible, without having to detect it using re-transmission failures 
etc.

Another example in the mobile world is related to codecs and DSP resources. If 
you have negotiated codec X only for one early dialog, and that dialog is 
terminated, you know that you can free the codec X resources (you can do that 
without having to be able to associate media with dialogs) and e.g .. allow 
reservation of other codecs needed for other dialogs. Especially when we move 
into the world of multimedia, using video etc, this kind of functionality 
becomes important. 

Another example in the mobile world is radio resources. In case of forking and 
multiple stream there may not be possible to allow early media on all dialogs, 
so some dialogs may e.g. be set to "inactive". It is then very useful to know 
when a dialog is terminated, so that media can be allowed on other dialogs. How 
those inactive decissions are made is based on local policy etc, but 199 
provides a tool which is useful for taking those decissions.

Due to the cases above, and others, terminals may restrict the number of 
accepted SIP dialogs, so by knowing when one dialog has been terminated it can 
accept another dialog.

These are not theoretical issues, but problems that exist today. Maybe not in 
your PC with unlimited memory, connected to fixed access with unlimited 
bandwidth, but in some other places :)

>If SRTP actually solves the problem for media choosing, then let's state it in 
>the 
>document.

Sure, I can do that.

Regards,

Christer
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