[standards-jig] [jepnews] JEP-0020: Client Feature Negotiation

Thomas Parslow (PatRat) tom at almostobsolete.net
Thu Feb 28 21:37:09 UTC 2002

> Feature negotiation is the next step after finding out that a client
> supports a specific namespace. Thus, it actually "extends" the browsing
> aspect to find out if an endpoint supports something. The negotiation would
> be used to allow 2 clients to 'agree' on the specifics for a specific
> namespace (the examples show the clients picking key-exchange methods). Both
> clients support jabber:crypto:keyexchange, but they need to "coordinate" and
> pick the key-exchange method that they both support.

> Another perfect example could be jabber:iq:oob (for file transfers). Client
> A browses to find out that the recipient's client can receive files (it
> supports the namespace). Client A then uses the negotiation protocol to find
> out if the Client B can originate a P2P connection since Client A "knows"
> that it's behind a firewall. This way, Client B can "listen" on a specific
> IP/Port, send that back to Client A using the negotiation protocol, then
> Client A connects to that socket and sends the file. Currently, we have no
> protocol for allowing this type of exchange.

> Hope this clarifies the purpose and need for this protocol.

> Peter Millard.

Wouldn't it be better to extend the jabber:iq:browse namespace rather
than creating a new one? It seems that there is a bit of overlap
between jabber:iq:browse and the namespace proposed in JEP-20...

Thomas Parslow (PatRat)
E-Mail/Jabber: tom at almostobsolete.net
ICQ: 26359483

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