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My First MPLS over Satellite Videoconferencing Call

March 13, 2012 | Howard Lichtman
Telepresence Options Publisher Howard Lichtman on the roof of the Walter E. Washington DC Convention Center with an EMC 2.4 meter satellite dish delivering 2MBps of MPLS over satellite

It is easy to find your way to the Emerging Markets Communications' (EMC) booth at the Satellite 2012 trade show being held at the Washington DC convention center.  You simply follow the cable bundle that snakes across the ceiling of the convention center and then drops straight down to their booth.  The cable is carrying 2MBps of MPLS bandwidth that EMC is pulling out of the sky with a 2.4 meter dish on the roof with all the Quality of Service needed for crystal clear telepresence and videoconferencing. 

A video over satellite call to Miami using 1MBps of MPLS bandwidth and
a Cisco EX20 videoconferencing endpoint.

As an ex-networking guy who use to build global networks for the financial industry I had been skeptical about the ability for a satellite link to control for the jitter, packet-loss, and latency needed for high quality video.  I am now a believer.  The test call that we placed to Miami was using 2MBps of traffic with 1MBps devoted to videoconferencing.  The signal was getting bounced from DC to a satellite to an EMC teleport in Hawaii, then from Hawaii the call took a second satellite bounce from Hawaii to Miami.  This is an unusual topology for EMC as the majority of calls are a single satellite hop away from a terrestrial or submarine network. 

That unusual route added an unusually high 749 milliseconds of latency to the 70-150+ milliseconds of latency that most videoconferencing codecs inject into the process. The company was able to achieve a sub-400 millisecond latency in a second one-hop test call that connected to the former Miss Hawaii located in EMC's Hawaiian teleport. EMC tells me the usual latency is in the 425-475 millisecond range.  I had been expecting that latency to be obvious in the call but found it only slightly perceptible in normal conversation.  It was more obvious when doing a "count test" where I would count a number in Washington, DC and my test subject in Miami would count the next number in sequence.  The count test made it obvious that there was almost essentially a one-second lag between the numbers (neural processing aside) but the brain seems to smooth that out in normal conversation as it processes the information received and formulates its natural response.  Definitely not a bad trade-off for the capability to provide the MPLS connectivity required for telepresence and videoconferencing to 196 countries across the world.  The other 1MBps of bandwidth from the connection was being used to demonstrate satellite LAN connectivity for a typical small office environment but the 2.4 meter dish can support up to 45 MBps up and down depending on the exact location in the world.

The price is definitely more than a terrestrial connection but not as bad as I had expected given the capability.  They asked me not to publish that because, like most telecommunications services the cost varies widely depending on term, number of sites, bandwidth, and 10 other variables.

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