Networking

Got Bandwidth?

Video-heavy distance learning programs can put a strain on the campus network. Here's how three institutions are managing bandwidth to ensure high-quality service for eLearning students.

Got Bandwidth?IT'S NO SECRET that distance learning programs can wreak havoc on a campus network. Inherent in the equation are problems of increased latency and depleted bandwidth as an institution reaches out to more students. The more students connecting remotely, the harder it is to maintain the levels of service required to keep those students satisfied.

The College of Engineering at Villanova University (PA) has tackled that problem head-on: Under the auspices of Sean O'Donnell, the college's director of distance education, technologists have embarked on a new program to minimize bandwidth and maximize throughput during distance education sessions, promising service levels that are ostensibly no different from the ones users can expect when they're connecting from a terminal on campus.

"We believe the fact that people are connecting to the network remotely should have no bearing on the kind of experience they have once they're in," says O'Donnell, who notes the network now supports upwards of a total of 150 megabytes per second for all users. "The process requires planning, but is perfectly doable once you know what you want."

The Situation

Through its online master's degree program, Villanova's College of Engineering serves about 400 students annually. In the past, the school was using RealVideo to deliver lectures over a bandwidth pipe that maxed out at a total of 66 megabytes per second for all users. As bandwidth demands increased, however, this method became unreliable.

In order to guarantee live presentations with absolute minimum delays, IT officials decided it was high time to optimize throughput across the board. To do this, they built a private network between servers and capture stations, and linked that directly to the campus backbone via fiber optic lines. O'Donnell says this ensured that eLearning traffic was not cluttered with normal network congestion and had priority.

With this new setup in place, Villanova opted to run its asynchronous distance education system over the Mediasite system from Sonic Foundry. Every user who accesses the system now requires no more than 200 kilobytes of bandwidth to access the material-- 150 kilobytes for a video stream and 50 kilobytes for files of other types.

Key Question No. 1: Video Quality

When tasked to manage this bandwidth for the College of Engineering, O'Donnell and his colleagues say they asked themselves two key questions-- the first about video quality and the second about usage tendencies.

The first question was simple: What quality is good enough for the material that users hope to access?

Here, O'Donnell and his colleagues interviewed a series of students to get a sense of the quality of material they were hoping to download during their average distance education session. Turns out, most students were just looking for documents and basic video-- nothing exceptionally fancy.

"If you're not really into high-motion video-- if you're more just relying on talking heads-- you don't need to waste money on bandwidth streaming high-definition stuff that shows you beads of sweat on everyone's forehead," he says. "The common mistake I see people making is that they over-qualify video for the type of material they're distributing and end up losing bandwidth in the process."

O'Donnell adds that as compression algorithms and video servers have improved in recent years, higher education institutions have been able to get clearer video for less bandwidth-- and therefore less capital investment.

"The quality we see now at 150 kilobytes per second, we used to see only at 400 kilobytes per second," he notes. "In terms of management, it lets you do more with less."

Key Question No. 2: Usage

The second question O'Donnell and his team members asked pertained to usage: How many simultaneous live viewers was the College of Engineering's distance education program going to have?

According to O'Donnell, distance education particularly starts taxing network bandwidth when it tries to serve simultaneous viewers, like for a live event. But because most distance education users access events from an archive after the fact, servers only use the bandwidth that's available-- a process called "buffering."

"For most people, the reason they are doing distance education is because they don't have time to attend an event live," he says, noting that the highest number of live viewers Villanova ever has seen at one time is about 70.

In order to keep better tabs on available bandwidth, O'Donnell admits that he and his colleagues considered capping the number of simultaneous live viewers. In the end, however, the team opted not to go this route, out of concern for tinkering with the open nature of higher education.

Getting Buy-In

With the new Sonic Foundry system in place and bandwidth issues resolved, the next step for Villanova's College of Engineering was to educate students and faculty members to fully utilize the resource. Skeptical faculty members were a bit of a challenge: O'Donnell notes that despite the bandwidth and service improvements, some were reluctant to embrace a new system.

"These people get so used to doing things the way they've done them for years, that it's hard for them to pick up new technologies right away," says O'Donnell. The solution? In the case of the College of Engineering, at least, it was regular meetings and a propaganda campaign designed to help familiarize users with the interface.

"Communication definitely helps," O'Donnell quips. Indeed, sometimes the best way to manage anything is to just get users talking about it.

A Different Approach

While the folks at Villanova treat bandwidth for distance learning separately from bandwidth for the rest of the network, technologists at the University of Arizona and the University of Wisconsin System take a different approach: They don't differentiate bandwidth at all.

The thinking at both of these institutions is the same: They have plenty of bandwidth to go around, so there's no need to monitor any one segment of the network more than the rest.

At the University of Wisconsin system, Lorna Wong, interim director of learning technology development, says that a distance learning system from Desire2Learn provides more than 1 gigabyte of bandwidth to each of the system's institutions, and that at peak times, the institutions use no more than 10 percent of this available bandwidth.

"Our network folks did their calculations and are confident we can meet just about any need that arises," she says. "From this perspective, it doesn't matter to us what bandwidth is going where, so long as we have enough to go around."

The University of Arizona also uses Desire2Learn, and takes a similar approach. Christopher Pierce, an analyst in the University Information Technology Services department, notes: "All requests for bandwidth are provisioned as needed and managed together with [the whole] IT infrastructure."

Despite keeping all bandwidth lumped together, technologists at both schools say they monitor bandwidth closely. At U of A, technicians recently have rolled up functions of various monitoring and management tools into one comprehensive system: EM7 from ScienceLogic. While UW's Wong declined to share specific tools used throughout the University of Wisconsin System, she notes that the existing tools monitor traffic by site, and some by IP ports.

Wong adds that in many cases, students who experience bandwidth issues when they connect through the distance learning system actually are experiencing difficulties on the connection side, not with bandwidth on the Wisconsin side.

"It could be any number of factors-- from an ISP to a firewall or a personal desktop," she explains. In those instances where UW technicians find out students are experiencing bandwidth problems at their connection point, Wong notes the technicians will work with instructors to send students CDs of lecture material or find other ways to accommodate them. "It's all about the students," she says. "We think we're in shape to give them all they need."

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