College Users Fill the Pipe

Hanover, N.H.-based Dartmouth College is well-known in wireless
circles for being one of the first colleges to embrace Wi-Fi technology.
Recently, the college went through a network upgrade.

The original network, says Brad Noblet, Dartmouth director of technical
services, cost $1.2 million. That covered 200 access points
and the wiring they
required. “Now we want to go to 1,500 APs.”

But that’s not all. The original Cisco APs were 802.11b only, and now the
college wants to serve 802.11a, b, and g, using Aruba 52 APs.

Of course, the college doesn’t sell wireless, so that’s not the problem.
“People on the campus love wireless. The challenge is capacity,” explains
Noblet.

These are heavy users. Students do language lab classes from their own room
using video over IP, for example, and Noblet admits that heavy use of video on
the network presents a real capacity challenge.

“802.11a is good for this, because it provides a lot of bandwidth. Also, it’s
orthogonal, which is good for a campus with a lot of reflections and
interference.” The problem with 802.11a is that you get a much shorter range out
of it. Noblet estimates it provides full rate only if you’re within 120 feet of
the base station.

So the college is looking at other technologies, too (just as WISPs across
the country are experimenting with everything new). “We’re experimenting with
mesh technology,” says Noblet. He feels it’s especially useful for a problem
some colleges face. When the incoming class is larger than expected, the college
builds temporary student housing. If you need to hook up temporary buildings
quickly, mesh is a great way to do it.

However, APs in such buildings need to have power. Noblet would love to be
able to supply power through microwave, just as other APs get power over
Ethernet, but the technology is not yet available.

The toughest problem of a larger network is management. “The network is open.
Visitors can plug in and log on. Authentication does not solve virus problems.
We have to authenticate and patch users before they log on.”

For permanent off campus housing, not the temporary structures, Noblet
prefers to run fiber above ground along utility poles. “They have an obligation
to allow us to run fiber on the poles, but they’re in no hurry,” he complains.
ISPs across the nation know exactly what that’s like. In a few cases, Noblet has
been forced to turn on DSL circuits while waiting for the fiber paperwork to go
through.

Given all of these constraints, it may seem surprising that Noblet’s
expanding the network at all. But as every service provider is finding, there
are more applications for IP every day. It may not be true everywhere that if
you build it they will come, but if you’re a college and you’re offering free,
high quality service, you will find that service used to the limit.

Reprinted from ISP Planet.