By Johna Till Johnson

Video conference users have for the most part been free of the hassles of trying to figure out how to interoperate products from different vendors, thanks to early and widespread adoption of H.323 signaling protocols and H.261 and H.264 video encapsulation, both sets of protocols well defined by the ITU.

Telepresence is a whole different story, however. Many vendors are using proprietary approaches for signaling and/or codecs. And telepresence introduces new requirements such as switching screens to active talkers, and directional acoustics that matches the direction of someone's voice with the proper display in a multi-screen session. The lack of open, well-defined standards has led telepresence vendors to resort to proprietary approaches for solving these problems. The end result? Telepresence interoperability hasn't been possible--until now.

Thanks to demand from -the users---this has started to change. At October's Internet2 meeting in San Antonio, TX, Polycom, LifeSize, and Tandberg took part in a multi-room telepresence demonstration across 12 locations, mixing together not only their own systems, but also systems from Cisco (with Tandberg codecs) and Sony.

This test provided a proof of concept that interoperable telepresence was possible. But it also exposed the difficulty in delivering a practical, usable interoperable solution. Organizers noted the need to bridge across Tandberg and Polycom MCUs for example, as neither MCU could support a competitor's multiple screens (instead treating them as a single screen system). Organizers also noted difficulty in mapping screens to location, so right-to-left layout of screens appears consistently across all locations.

A second development is Cisco's recent announcement of a Telepresence Interoperability Protocol (TIP), which defines common approaches to issues such as acoustical direction, screen mapping, and screen switching.

Cisco says it plans to release this protocol to competitors, and to standards bodies to continue development. Let's hope so, but the ury is still out as to whether or not telepresence competitors such as HP, LifeSize, Polycom and Teliris (and even Tandberg if the Cisco acquisition falls through) will adopt TIP. Cisco also recently announced that it will provide a gateway to enable connectivity between its telepresence suite and any other standards-based video conferencing system, achieving the same level of interoperability between telepresence and room systems as currently offered by LifeSize, Polycom, and Tandberg.

So while telepresence interoperability isn't quite there yet, it's getting better. Now, buyers of telepresence systems can rest assured that they can integrate their room and desktop systems into their telepresence platforms to achieve a seamless conferencing experience for any user. It shouldn't be too much longer before full interoperability between telepresence systems exists beyond research projects and public demonstrations.

[via Network World]