Alban Crequy wrote:
> Le Tue, 14 Oct 2008 10:33:20 -0600,
> Peter Saint-Andre <[EMAIL PROTECTED]> a écrit :
> 
>> Alban Crequy wrote:
>>> Hi,
>>>
>>> To start a link-local conversation with XEP-0174 between two
>>> clients, any of the 2 clients can initiate the stream. If the 2
>>> contacts start to chat at the same time, we may have 2 streams
>>> initiated in both directions. It seems this case does not happen
>>> often because users usually don't start to chat precisely at the
>>> same time.
>>>
>>> You suggested that having several streams between 2 clients was not
>>> a problem:
>>>
>>> Le Thu, 14 Aug 2008 10:51:06 -0600,
>>> Peter Saint-Andre <[EMAIL PROTECTED]> a écrit :
>>>> Alban Crequy wrote:
>>>>> If we want the XEP to say there can be only one stream between two
>>>>> clients, we should define the correct behaviour when two clients
>>>>> initiate a TCP connection to each other at the same time. Do we
>>>>> want one connection to win and the second to be closed?
>>>> I don't think we need to restrict clients to one stream at a time.
>>> However, if the 2 clients both implement XEP-030 Service Discovery
>>> and XEP-0115 Entity Capabilities, they will both initiate a stream
>>> in order to send a discovery request as soon as they appear online
>>> via DNS-SD, without user intervention.
>> Really? I thought we were advertising caps in DNS TXT. See the "ver"
>> record here:
>>
>> http://xmpp.org/extensions/xep-0174.html#registrar-linklocal-reg
> 
> Indeed, we know the "ver" record without opening a stream. But the
> "ver" record is not enough to know all the caps.
> 
>> So I think that opening a stream to everyone who appears online via
>> DNS-SD is a bad idea.
>>
>> Thus I would say that if you know the "ver", you'll know what the
>> other entity is. But if you don't know the "ver", don't automatically
>> open a stream to the other entity just to do all the caps lookup
>> magic via disco.
> 
> I need to know all the contact capabilities in Telepathy, even if there
> is no open stream. If an application want to display a contact chooser
> to start a VNC session, a game, or whatever on top of XMPP, I need to
> know which contacts are able to do VNC or a specific game.
> 
> I implemented an automatic caps lookup via disco in telepathy-salut
> (the XEP-0174 implementation in the Telepathy framework). It opens a
> stream only if a "ver" TXT record is advertised *and* if the "ver"
> record is not already known.

Right, I see the need for that. But it's unfortunate.

Still thinking...

Peter

-- 
Peter Saint-Andre
https://stpeter.im/

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