Asterisk 1.4 introduces a new level of Jabber integration, developed by Matthew O’Gorman at Digium. The Asterisk Open Source PBX integrates with Jabber/XMPP in many ways.

* Google Talk channel driver: chan_gtalk. Google Talk is based on Jabber protocols, in the IETF named XMPP. Google extended Jabber with multimedia support and named the new extension Jingle. In the XMPP Foundation standardization process this standard has been developed a bit further, so in a coming release of Asterisk there will be separation between the “old” Google Talk channel driver and a standard-compliant Jingle channel.
* Jabber presence support in the dialplan: By letting your Asterisk connect to a Jabber server by using a Jabber account, you can add buddies to that account and check the buddies presence in the Asterisk dialplan. This way, call routing decisions can be based on the status of Jabber accounts. If Alice sets her presence to Away, Asterisk can send her calls directly to voicemail without ringing her desktop phone.
* Asterisk as a Jabber module: In a more advanced mode, Asterisk can register itself as a module to your Jabber server (as a Jabber component). This mode means better integration to Jabber, but requires more from the Jabber clients.
* Sending text messages: Asterisk supports sending text messages to Jabber clients from the dialplan, maybe alerting about upcoming conference calls, voicemail or missed calls. With Jabber clients making its way to cell phones and all kinds of devices, this means reachability everywhere.

Don’t forget that Jabber is an IETF/XMPP foundation standard that is implemented in both commercial software (like Apple’s iChat) and Open Source. Many libraries exist for Jabber development. There are also gateways to all kinds of presence platforms, including MSN and SIP/Simple. By integrating Asterisk and Jabber, you can now easily build Asterisk solutions with integrated presense and instant messaging support!