Nefsis Delivers HD Videoconferencing to the Desktop - Page 2

Nefsis Professional, the latest offering from a videoconferencing pioneer, promises HD quality in multipoint conferences.

 By Gerry Blackwell
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Bandwidth, of course, is a huge determinant of conference quality. So is the distance and number of router hops between participants and the Nefsis servers used.

Nefsis won't say how many servers it has, or where exactly they are, but claims to have presence all across the U.S. and in 45 countries, including Canada and the UK where our participants were located. It also boasts that the technology automatically selects either the closest or least congested servers to ensure optimal performance - i.e. with the least amount of latency or delay in voice and video.

The first conference we tried had four participants, three of them, including the host, in the same facility in Canada, sharing a cable TV Internet service with 10 Mbps downstream and only 500-Kbps up. The fourth participant was in the UK. The three participants in one facility probably put a severe strain on the Internet service there, especially the uplink.

Video, which we set to a fairly modest 320x240 and 15 frames per second - so well short of HD-quality - was generally good, certainly superior to Skype video. But video windows were kept small, and when there was other sharing going on, motion grew choppy.

When we tried to share a video file in the sharing window, something that had worked reasonably well in the briefing with Nefsis, the audio was good, but video was reduced to about one frame per ten seconds - not really video at all.

During most of the conference, latency on the audio side made carrying on a normal conversation difficult but not impossible, and there was some clipping - loss of audio signal - especially when two people were talking at once, and severe echo at times. When three participants spoke at the same time, the audio was almost completely unintelligible.

In a second four-way conference with participants in four different locations in southern Canada, results were similar. Echo, delay and clipping were all problems on the audio portion, though not as severe as on the first conference. Video varied in quality but was generally acceptable.

This article was originally published on May 7, 2011
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