server-to-server communication (was: A jabber hosting offer)

Simon McVittie simon.mcvittie at
Sun Jan 6 18:52:50 EST 2008

On Sat, 05 Jan 2008 at 22:01:03 -0700, drew einhorn wrote:
> If we are going to have small local communities instead of one big one,
> the we need to be able to contact multiple jabber servers

The underlying protocol of the server-based collaboration is XMPP. In
XMPP, you never need to connect to more than one server unless
you need more than one "identity" (e.g. personal and work addresses) -
servers communicate among themselves to forward their users' messages, just
like e-mail ("server federation" in XMPP jargon).

Server federation is a high priority as a future feature, but the current
Activity protocol doesn't scale beyond one smallish server, because of the
Shared Roster hack. We have people working on a replacement Activity protocol
involving a "server component" that acts as an activity registry, that can
work correctly across federated servers, and doesn't require that everyone is
on everyone's roster ("buddy list") at the XMPP level (this is the Shared
Roster hack that causes us so much trouble in both ejabberd and Openfire).

In principle, once we get a scaleable activity protocol, (a) we'll be
able to fit many more XOs on one server, and (b) there'll just be one
big worldwide community (school servers can become part of the existing XMPP
network, which includes e.g. and Google Talk) and kids will be
able to add friends on other servers. Obviously, there are UI and
privacy issues to be solved before we open up connectivity between
servers, but it's definitely the plan.

So, in summary: yeah, we're on it :-)


(no longer working on OLPC myself, but previously part of the Collabora
OLPC team)

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