Re: [Stox] core issues

[Paul Kyzivat <[e-mail]>]

On 8/21/13 3:17 AM, Daniel-Constantin Mierla wrote:
>
> On 8/21/13 1:50 AM, Paul Kyzivat wrote:

>> You can make it sound easy by ignoring the details, but at the expense
>> of quality of implementation.
>>
>> The problem is that you may get multiple early dialogs, with media. At
>> that time you don't know which one will answer first. So what do you
>> do with the media while awaiting a 2xx?
>>
>> You can't "pick one" without the risk that it is the wrong one.
>>
>> You can "pick one" and switch it if it turns out to be the wrong one.
>> But unless you relay the media the xmpp side will see a change, and so
>> there must be some plan for how that is handled.
> My comments were for the remark related to multiple 200ok, I haven't
> said sending BYE for additional early dialogs.

They are tightly connected issues.

> For multiple early dialogs, the gateway has to maintain all of them
> until a 200ok. It's also implementation decision which of early media
> streams is sent to xmpp/jingle (again, it looks like it's mostly the
> first one from experiences out there).

This is straightforward if the GW terminates/relays media.
But that is a cost.

A signaling-only GW can't easily or thoroughly prevent the multiple 
early media streams from reaching the xmpp client. (It may be able to 
send updates to all but one to stop their media, but that takes some 
time, and not all will support it.)

So either you mandate that the GW terminate the media, or else you have 
to acknowledge the situation and warn the xmpp client to be prepared.

	Thanks,
	Paul