Wide Area Conferencing
THE POPULAR colloquialism, ?They do things big in Texas,? certainly must have a lot to do with physical geography. The University of Texas' Health Science Center (HSC), based in San Antonio, illustrates that dynamic in the way it virtually links medical, dental, and nursing teaching facilities that are spread out all over the Panhandle, in places like Laredo and down into the Rio Grande Valley as far south as Edinburg. The HSC has built a vast Polycom-based videoconferencing network, connecting more than 60 disparate rooms ? AV-equipped classrooms, lecture halls, labs, and auditoriums, spread out all over South Texas. And it controls it all over a single wide-area network (WAN) from a head-end location on the main campus in San Antonio.
At the time, the HSC's WAN relied on H.320 protocol, which supported only older telephony-based videoconferencing. H.323 — a more modern protocol for AV data transmission over networks — was just beginning to gain wide acceptance.
“We immediately moved from H.320 to H.323,” Baggs says. “That change ultimately made it possible to bring videoconferencing into the network, and bring control of the classrooms onto the network.”
Transitioning to H.323 meant that “the network guys had to rebuild the WAN architecture,” he notes, with specialized Cisco routers and processors integrated into specific network end-points. In terms of funding, Telemedicine Department needs ranked as high-priority for top-level HSC administrators, who spared no expense to see that they were met.
The same dynamic applied to bandwidth on the WAN — the department's videoconferencing efforts would be allocated as much of the pipe as it took in order for the system to work effectively. That meant that each facility would receive a dedicated fiber-optic trunk for the transmission of video. “I didn't understand (network technology), but I knew that if I didn't fight for enough bandwidth, the system wouldn't work,” Baggs says.
“With fiber transmission, the picture going in is as good as the one going out,” Winnick adds. “And the doctors were much better able to rely on the images for evaluation purposes.”
Ultimately, due to a variety of factors including liability — and despite the huge investment in establishing the H.323 network wherewithal — the Telemedicine Department abandoned use of the videoconferencing system. However, having spent millions of dollars to upgrade their network, the school's administrators were quick to recognize the opportunity for the classrooms that were being built at the time.
“When the new classrooms came along, they could just piggyback on the H.323 network backbone that had already been built for the Telemedicine Department,” Baggs explains. “They benefited from the fact that (millions of dollars) was spent to make a run at enabling videoconferencing for telemedicine.”
In the beginning, as they figured out how to use Crestron's then-new e-Control, HSC network administrators grappled with such issues as security — remote access through e-Control opened up a number of potential security breaches on the network, for example.
“One of the biggest obstacles we faced was opening the firewall to all these various ports and not compromising security,” Garcia notes.
Working with several programmers dispatched by Crestron, HSC network operators were able to overcome these challenges by creating a secure, self-contained virtual LAN (VLAN), which safely sheltered Crestron control processors in the classrooms, conference rooms, and auditoriums from the broader WAN environment.