[Standards] Namespace Priority
ian.paterson at clientside.co.uk
Tue Mar 13 00:27:03 UTC 2007
Peter Saint-Andre wrote:
> Ian Paterson wrote:
>> There seems to be a real need. We've already got servers like Tigase
>> implementing proprietary functionality. Shouldn't we at least
>> standardise something? Why shouldn't we define a protocol (perhaps
>> something like this:
>> to enable those applications that want to support specialized content
> Can't the server already figure that out based on RAP? It could use
> the RAP info for routing stanzas sent to the bare JID even in cases
> where the contact does not receive the user's presence. But it's not
> clear how that applies to IQs, if at all.
It doesn't apply to IQs. But, as you mention below, protocols like
Jingle can still use IQs because a client can first perform a Session
Negotiation (XEP-0155 or XEP-0116) in order to discover the resource of
the other entity before sending an IQ.
A server could use the RAP elements it receives in presence stanzas from
its users to understand which namespaces each connected resource
supports. However RAP elements are currently not designed for that.
Furthermore, it doesn't help anyway, since servers would still have no
way of understanding to which resource a Session Negotiation request
should be delivered (since the sender currently has no protocol to tell
the server that the request should be sent to a client that supports,
for example, Jingle).
RAP only solves the issue for people who I allow to subscribe to my
presence. So IMHO the solution should not involve presence stanzas at
all. The alternative proposal outlined in the URL above does give
servers a bit more work when delivering <message/> stanzas to bare JIDs,
but it has several advantages:
1. it works for non-subscribers
2. it keeps presence stanzas small
3. it is even more simple for clients
> Negotiate a chat session via XEP-0155 to request an audience, when it
> starts exchange directed presence, then do your IQ stuff for Jingle.
> Seems straightforward to me.
How can the initiator (who is not a subscriber) tell the other user's
server that its XEP-0155 session request should be delivered to the
resource that supports Jingle? Even after the initiator discovers that
the resource the request was sent to does not support Jingle, it still
has no protocol to tell the server to deliver any subsequent request to
a different resource.
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