[Standards] Jingle initiate and resource determination

[Ian Paterson]

Lauri Kaila wrote:
> Hi Ian,
>
> 2007/6/6, Ian Paterson <ian.paterson at clientside.co.uk>:
>> > What do you think about this idea: Jingle session receiver publishes
>> > session-initiate, accept and terminate stanzas. That would provide
>> > means to implement "someone calling/sends a file to your PC" note on a
>> > mobile device.
>>
>> Sorry, I didn't understand your idea. Could you please expand it. 
>> Thanks.
>
> OK - I'll try. I haven't studied Publish-Subscribe and PEP enough to
> be more precise, but I assume that it would be quite easy to
> distribute Jingle stanzas between a person's own XMPP clients using
> the same account. XEP-0166 would need to define more specifically how
> to get these "Jingle action events".

Technically it would be trivial to forward the stanzas to the other 
resources (there would be no need for pubsub or PEP). But, in any case, 
the other resources wouldn't be allowed to reply to the session-initiate 
(since only the original recipient is allowed to reply to an <iq/> 
stanza). i.e., the advantage of forwarding would be purely "FYI".

Furthermore, Ralph (yes he is alive) reminded me that the reason we 
haven't accepted a standard for indicating the original sender of 
forwarded stanzas is the difficult trust issue that  inevitably arises. 
You could argue that those problems don't arise when forwarding between 
resources of the same bareJID. However, I'm not yet convinced you have 
identified a compelling use case.

> That would be enough to ensure that a call is never missed because of 
> the priority values.

AFAICT the proposed Namespace Priority approach solves the significant 
issues. Have you identified real-world scenarios where calls will be 
missed because of the priority values?

If you have then a more simple fix might be to employ the existing 
<redirect/> error (as defined in RFC 3920). This allows the resource 
that receives the session-initiate to indicate to the sender that it 
should instead try opening the Jingle session with another specified 
resource.

- Ian