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In postings last August and September I reviewed how a few small vendors are creating connections allowing video conferencing and telepresence to cross the boundary between companies and thus create Business to Business (B2B) video connections. We have seen a number of announcements from major WAN service providers announcing similar capabilities, albeit within their own networks, primarily focused on supporting Cisco Telepresence. While this is all good, it raises a bigger question. How compatible are the current telepresence systems and what happens when we try to connect them?The first problem is the interconnection, done either via the Internet or via one of the services mentioned above. The Internet has no bandwidth or QoS guarantees, but works well on a good day with a tail wind. The carriers providing B2B support provide both bandwidth and QoS within their own networks. So if the business partners with whom you want to connect use the same service provider, you can make it work. The real solution will be video exchange points which are starting to appear, where enterprises and carriers can interconnect and ensure QoS support across enterprise and carrier boundaries. Assume for the sake of this article that this problem is solved, even though we are not quite there yet.

The next interoperability problem is the video conferencing signaling protocol. Systems from LifeSize, Polycom and Tandberg all use the H.323 protocol and thus can be expected to interconnect. These same systems also support the SIP protocol and can use that to connect as well. Cisco and HP Telepresence solutions, however, use proprietary protocols that are not compatible with the video conferencing industry standards, and so each requires a gateway; a system server that will translate between one protocol and the other to support interconnection.

These translation gateways are a kludge that needs to be eliminated if B2B Telepresence is to become a success. Today these gateways only support a low CIF resolution image. HD video at 720p is about 9xCIF resolution as a comparison. Furthermore these gateways become a concentration point for video bandwidth in the network and will prevent simple scaling of video interconnect.

So take a deep breath and create a willing suspension of disbelief and assume that these gateways dissolve away in a year. Now we are left with a basic incompatibility between the way the telepresence systems are designed. Telepresence systems use multiple cameras looking out at a single room to create an image for the far end. Some systems use two, some three and some four cameras and screens. The angles of these cameras, the furniture in the rooms, the graphics at the back of the room and the microphone placement are all carefully crafted. When we mix two vendors' systems which are designed around different principles, we will get the disconnects that these separate design decisions create. Mismatches of color temperature, audio, screen layout, image ratio, eye contact lines and more may make these connections substantially less immersive than the single-vendor solution.

The single-codec video conferencing market has none of these issues beyond the basic connectivity and QoS requirements. With the exception of Cisco they speak a common protocol, can negotiate capabilities and create a reliable, HD-resolution image. Perhaps the next few years of B2B video conferencing will be dominated by single-codec connections while we wait for telepresence standards to emerge.Perhaps the next few years will be dominated by single-codec connections while we wait for telepresence standards to emerge.

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