The fall forum of the Women in Engineering Advisory Committee (WEAC), held last month at Ryerson Polytechnic University in Toronto, was seen live and interactive on the Internet through IP videoconferencing technology.
IP videoconference technologies from Cervervision, a reseller and designer of standards-based video technology, helped the WEAC and Ryerson host a full screen, full motion conference that was available to remote partners from a web site.
Leela Ramparas, planning manager of presentation technology at Ryerson, negotiated with Cervervision to provide Internet videoconferencing for the forum.
“I had been aggressively looking at videoconferencing over IP, for moving audio, video and data in a truly real-time interactive mode over the Internet. We don’t have a videoconferencing system here at Ryerson…We have a satellite down-link capability, but we don’t have any real-time videoconferencing and so I had been searching for a solution and seeking an opportunity to do a pilot because this is leading edge technology,” Ramparas said.
Cervervision used an Intel TeamStation to provide the CODEC and web-casting over a G2 server. The camera provided by Cervervision was for a VGA-based broadcast. Ryerson provided five microphones for the panel speakers. The audio signals went into two audio mixers and were amplified and distributed, after being split by two audio distribution amplifiers. They were then sent along with the digitized and compressed video signal via the Internet to Laurentian University in Sudbury, Ont., where the conference was broadcast as live and interactive. In addition other universities were allowed to view the broadcast, but not interactively.
Mitch Stein, vice-president of Cervervision Communications Inc. said the benefit to Ryerson was that it allowed the university to broadcast the conference and use its existing network without having the expense of installing additional switched lines.
“This was a pretty big initiative for us. When we usually go and install this type of equipment over an existing network there are a number of variables that need to be addressed. The first thing is how
much bandwidth is available for the application and what is the latency, in terms of how fast the packets move from point A to point B, is it going through 15 different hops, and routers and switches before it actually gets to the final destination,
and then when there’s packet loss or jitter — any of the issues with IT networks — what’s going to happen to the audio and video?” Stein said.
One of the reasons there is not a lot of competition for Cervervision, said Stein, is that “the IP side is much more complicated than traditional switched networks.” For example, there were some major network hurdles for Cervervision to overcome in setting up the WEAC videoconference.
The first problem encountered was the network between Ryerson and Laurentian.
“We started the project with over a 600 millisecond delay, between point A to point B, and at the end of the network audit and through the network strategies that we put together we were actually able to bring that network connection down to less than 20 milliseconds,” Stein said.
The network audit is network testing to ensure that the connectivity between IP address A and IP address B is able to carry traffic fast enough and clean enough so it gets through.
According to Stein, Ryerson is connected to ONNet and CANet — two large research networks that are supposed to have a great deal of bandwidth.
However, the ATM engineers determined that only the CANet connection was feasible and that connection was actually going from Toronto to Chicago, Chicago to Ottawa, Ottawa to Sudbury and Sudbury over to the university.
“It wasn’t a direct connection from point A to point B. It was actually going through part of the Internet; so that was the challenge — how do you manage traffic over this pipe? Videoconferencing over the Internet doesn’t work [reliably] because you don’t know where your call’s going to go when you actually place it. It may bounce here, here, here and here and on the next minute you call and hang up it bounces in the opposite direction,” he explained.
Specific areas of latency in the network between the two universities was also found and had to be dealt with. Changes on the routers were made to make sure that packets were getting through and not hitting an error in the routers’ configuration.
Stein said that Laurentian and Sudbury Hydro had made some changes on their network a few weeks prior to the broadcast and when they had put the configuration back into the routers, a loop was created in a router and
packets were being lost.
Another issue with Internet videoconferencing is ensuring the network has QoS. With all kinds of other traffic running on a network, IT information tries to get there as fast as possible. If there happens to be video traffic running on a network on a continuous basis, a file goes right through those packets and the result is packet loss and choppy video or audio.
“Imagine somebody dropping a huge rock in the middle of a river and some of the water splashes out and it stops the river from flowing, but then the water covers the rock and can use the flow. That’s exactly how IP traffic works. It just takes a hit and what happens in video is that all of a sudden a person is talking and moving and poof there’s nothing there or the frame skips five, six, ten frames ahead
and then it continues along,” Stein explained.
The WEAC videoconference ran smoothly for most of the day, until a severe weather storm knocked out a main power room at Ryerson resulting in choppy audio being received at Laurentian. However, Leela Ramparas is undaunted and plans to hold another such conference again with Cervervision.
Stein also said that the conference was a success.
“[We were able to] prove the technology works and educate the marketplace that the stuff is ready for prime time. It works and the quality is fantastic. We have the expertise to go in and make it work for a customer from turnkey to handling the network end,” he said.
