[jdev] Serverless (peer2peer) jabber sessions

[Steve Smith]

> Well, a jabber server could listen on a multicast socket and upon 
> request return a service tag ( or something alike ) to the bone.

This service-discovery protocol already exists in the form of 
Rendezvous/Zeroconf, there's even a jabber service-type defined.  It's 
local-network only, but as someone said that's where it's interesting 
anyway.

One simple solution to the p2p setup is to embed a small standalone 
server into the client (if you remove inter-server routing and probably 
some other stuff the basic server should be fairly trivial (shout me 
down if I'm wrong on this)).  This mini-server/client publicises the 
service via Zeroconf, and chat is initiated by other clients discovering 
the mini-server and connecting to it.

The main problem is authentication, as you don't want to have to 
register for each p2p chat.  One possibility is to email-style 
certificates; if a person accepts, say, cacert.org certs then people can 
be 'identified' and allowed into the chat room as they connect, possibly 
on a case-by-case basis.  Has anyone done a server that uses certs as 
identification?  (I believe this can be done with the SASL EXTERNAL auth 
method, but I haven't looked that deeply into it).

Cheers,
Steve