Monday, October 19, 2009


On October 6, 2009, Bob Dixon from OARnet moderated successful telepresence interoperability demonstration at the Fall Internet2 meeting in San Antonio, Texas. It included systems from Polycom, LifeSize, and Tandberg, and the short version of the story is in the joint press release While the memories from this event are still very fresh, I would like to spend some time and reflect on the long journey that led to this success.

First of all, why is telepresence interoperability so important?

The video industry is built on interoperability among systems from different vendors, and customers enjoy the ability to mix and match elements from Polycom, Tandberg, LifeSize, RadVision and other vendors in their video networks. As a result, video networks today rarely have equipment from only one vendor. It was therefore natural for the video community to strive for interoperability among multi-screen/multi-codec telepresence systems.

Most industry experts and visionaries in our industry subscribe to the idea that visual communication will become as pervasive as telephony today, and it has been widely recognized that the success of the good old Public Switch Telephone Network (PSTN) is based on vendors adhering to standards. Lack of interoperability, on the other hand, leads to inefficient network implementations of media gateways that transcode (translate) the digital audio and video information from one format to another thus increasing delay and decreasing quality. While gateways exist in voice networks, e.g. between PSTN and Voice over IP networks, their impact on delay and quality is far smaller than the impact of video gateways. Therefore, interoperability of video systems – telepresence and others – is even more important than interoperability of voice systems.

The International Multimedia Teleconferencing Consortium (IMTC) has traditionally driven interoperability based on the H.323 protocol. At the IMTC meeting in November’08, the issue came up in three of the sessions and there were heated discussions how to tackle telepresence interoperability. The conclusion was that IMTC had expertise in signaling protocols (H.323) but not in the issues around multi-codec systems.

In February’09, fellow blogger John Bartlett wrote on NoJitter about the need for interoperability to enable business-to-business (B2B) telepresence and I replied on Video Networker, basically saying that proprietary mechanisms used in some telepresence systems create obstacles to interoperability.

In April’09, Bob Dixon from Ohio State and OARnet invited all telepresence vendors to the session ‘Telepresence Perspectives and Interoperability’ at the Spring Internet2 conference He chaired the session and, in conclusion, challenged all participating vendors to demonstrate interoperability of generally available products at the next Intrenet2 event. All vendors but HP were present. Initially, everyone agreed that this was a great idea. Using Internet2 to connect all systems would allow vendors to test without buying each others’ expensive telepresence systems. Bandwidth would not be an issue since Internet2 has so much of it. And since the interoperability would be driven by an independent third party, i.e. Bob Dixon, there would be no competitive fighting.

In June’09, I participated in the session ‘Interoperability: Separating Myth from Reality’ at the meeting of the Interactive Multimedia & Collaborative Communications Alliance (IMCCA) during InfoComm in Orlando, Florida, and telepresence interoperability was on top of the agenda.

During InfoComm, Tandberg demonstrated connection between their T3 telepresence system and Polycom RPX telepresence system through the Tandberg Telepresence Server. The problem with such demos is always that you do not how much of it is real and how much is what we call ‘smoke and mirrors’. For those not familiar with this term, ‘smoke and mirrors’ refers to demos that are put together by modifying products and using extra wires, duct tape, glue and other high tech tools just to make it work for the duration of the demo. The main question I had around this demo was why a separate product like the Tandberg Telepresence Server was necessary? Couldn’t we just use a standard MCU with some additional layout control to achieve the same or even better results? To answer these questions, we needed an independent interoperability test. Ohio State, OARnet, and Internet2 would be the perfect vehicle for such test; they are independent and have a great reputation in the industry.

Stay tuned for Part 2 about the challenges to telepresence interoperability …


  1. Stefan,

    We have publicly shown true telepresence interoperability between TANDBERG and Polycom as well as all standards compliant endpoints months before this Internet2 event. You will be happy to know that we have now expanded that interoperability from Movi to TANDBERG T3 to Microsoft OCS, Polycom and now Cisco.

    Have a look at the video:

    This represents a unique and powerful solution to the interop troubles seen by the other telepresence players in this market.

    Sean Lessman

  2. Wow, Great post,Nice work, I would like to read your blog every day Thanks

  3. I really appreciate your post. Interesting point of view. More thanks for sharing.

  4. You covered this idea rather well. Your ideas have caused me to rethink some of my personal views on Telepresence Interoperability. You have a persuasive way of writing. Thank you.
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