Programming Jabber

Using Services on Other Jabber Servers

This section describes a technique that we’ve already seen used implicitly in Section 4.16.3. That is the use of services on other Jabber servers. In reality, the example of running a Conferencing module in a satellite Jabber server showed the technique in the context of local administrative control; we control the main and satellite servers, and the module in the satellite server may rely on services in the main server for support.

Consider the <browse/> section in the jabber.xml configuration file that comes with Jabber server 1.4.1:

<browse>
  ...
  <service type="jud" jid="users.jabber.org" name="Jabber User Directory">
    <ns>jabber:iq:search</ns>
    <ns>jabber:iq:register</ns>
  </service>
  ...
</browse>

What’s this? A JID of users.jabber.org? How many Jabber server installations will be running with the jabber.org domain name? Yes, just one. This means that the <browse/> section is pointing to a JUD component running at jabber.org as users.jabber.org. If the Jabber server is running the Server (to Server) Connections and Hostname Resolution components, clients connecting to our server can transparently jump across the wire and avail themselves of the JUD services at users.jabber.org.

The entry doesn’t have to be in the <browse/> section. This is more for convenience, so that the clients can build a dynamic list of services from which the user may choose. The client may of course offer a facility for the user to directly enter the name (hostname, ...