[jdev] discovery services

Anthony Ortiz anthonypaulo at gmail.com
Wed Mar 23 18:45:35 CST 2005

"I SEE!!!" said the blind man to the deaf man...

That seems like an interesting idea, though I think the current jabber
protocol doesn't allow for this (am I right?) UDP/Multicast chatting
is old-school, but I had never thought of using xmpp over it. I'm
curious though... under this system, Jabber ID's will no longer be
unique since 2 or more people can connect using the same JID. How
would this system prevent this from happening? Since there's no
authentication mechanism, how would it prevent someone from logging in
as someone else and pretending to be that person? Is this defined
somewhere? I would love to check it out in more detail...



On Wed, 23 Mar 2005 19:20:46 -0500, Julian Missig <julian at jabber.org> wrote:
> On 23 Mar 2005, at 19:13, Anthony Ortiz wrote:
> > Okay, I'm confused... am I to understand that the jabber protocol can
> > be implemented over UDP/TCP-multicast?? I can see now how it would
> > sort of work... is there a JEP on this??? I would assume that it would
> > follow something along these lines :
> >
> > 1) client broadcasts its presence (<stream:stream
> > to="SomeJabberServer"> stanza I assume)
> > 2) jabber server ("SomeJabberServer") opens TCP/IP connection with
> > client
> > 3) ... authentication stuff happens here over dedicated TCP/IP
> > connection (don't need this stuff broadcasted) ...
> > 4) TCP/IP connection terminated
> >
> >> From this point on, I assume that everything else is handled via UDP
> > or multicast, except for messaging and file xfers and anything else
> > that is direct? Or am I just waaaaaaaaaaaaaaay off here??? If so,
> > would someone write down a step-by-step scenario of how this would
> > work?
> >
> iChat basically already does Jabber without a Jabber server. It is
> not /technically/ Jabber because we define Jabber as having servers,
> but it is possible. We're not talking about involving a Jabber Server
> at all.
> 1) Client broadcasts presence using Multicast DNS and DNS-Service
> Discovery
> 2) All clients on local network receive these presence packets as
> defined by those protocols
> 3) when user wants to send a message to another user, open a TCP
> connection
> 4) send messages over that direct TCP client-to-client connection
> 5) TCP client-to-client connection terminated
> Multicast DNS and DNS-SD are typically UDP, not TCP.
> This is *NOT* currently a defined protocol in any way, shape, or
> form. iChat does something along these lines. We're currently talking
> about IF we were to define such a thing how it would be done.
> Justin and I were arguing about what would happen at my step 4,
> except Justin's idea for how these steps happened seems to have been
> quite different from mine, which is why we both wasted so much time
> on it. :)
> Julian

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