Putting Wireless to the Test

FRAMINGHAM (04/10/2000) - University of Pennsylvania gives top honors to Cisco Systems Inc. gear for campuswide deployment.

The University of Pennsylvania's network already serves 40,000 users in 200 buildings, but soon its reach will extend even farther thanks to wireless equipment that provides mobile connectivity from anywhere on the Philadelphia campus.

Deke Kassabian, technical director for the school's Network Engineering, Systems and Services department, has been tracking the IEEE 802.11 wireless standard for some time. A new high-rate extension to that standard, 802.11b, supports wireless speeds up to 11M-bps. Once the network group believed the standard was reliable and mature, it decided to try the technology.

IT realized that wireless technology could be useful in several places around the campus. For instance, a short-range wireless link might be able to provide point-to-point wireless access to some locations that the school's PennNet network doesn't reach.

Wireless also might be able to connect areas where traditional structured wiring is not suitable. For example, the open interior of the school's Furness Library incorporates old stone and metalwork. Currently, fiber runs from the building's basement to the first floor, but adding wall plates and desktop connections would require drilling unsightly holes through stone, brick and iron, Kassabian says.

Moreover, Penn sets up a temporary ID processing center in a gym every year for new students. A wireless LAN might be ideal for short-term networks in such cases.

Evaluating the options

Kassabian worked with Eric Snyder, senior systems programmer; Kristina Victoreen, senior network engineer; Andy Diller, systems programmer; and Bill Magill, senior systems programmer, to evaluate wireless systems.

The team bought 802.11- and 802.11b-compliant equipment from several vendors, including access points and PC cards from 3Com, Apple, Cabletron, Cisco and Lucent (see graphic). It also tested Farallon Computing's 2M-bps Skyline Wireless PC Card but ruled out the product because it was expensive and didn't support the new 802.11b 11M-bps operation, Kassabian says. However, Farallon is scheduled to release an 11M-bps version of the Skyline Wireless PC Card this month.

Last September, the group began evaluating several aspects of wireless equipment. With the access points, the primary focus was on setup and configuration. However, the school also sought solid management and monitoring features and the ability to manage access to the devices.

With the client-side tools, which encompass PC cards and the full set of associated software, the network staff's criteria included support for multiple operating systems, signal monitoring, and easy setup and operation.

The department also looked for feedback from the user interface, which lets IT know at what frequency and over what channel the user has connected, and good site-survey tools. Site-survey tools help engineers test the efficiency and effectiveness of access points in various locations. Once an access point is in place, an engineer can plan wireless coverage by running the site-survey tool on a laptop and viewing interference as well as the access point's signal strength and quality.

IT set up the access points in its lab, then tried to get each vendor's wireless LAN card to associate at 11M-bps with access points from all other vendors in order to see what happened when it crossed vendor lines. After achieving interoperability in every case, Penn's network pros tested the hardware's network management capabilities.

Team members documented the products' strengths and weaknesses, along with any surprising results. What's more, staffers examined, but did not specifically test, each device's wired equivalent privacy (WEP) capabilities, which protect against eavesdropping and unauthorized network access. All but 3Com's AirConnect access points had reasonable WEP support, though 3Com is scheduled to add WEP support this month.

After comparing the test results, the school's IT department recently decided to deploy the Cisco Aironet 340 Series Wireless Access Points and Cisco Aironet 340 Series Wireless PC Cards for production use.

Penn rolled out four access points and 35 cards in February and is awaiting the delivery of four more access points and 30 cards. If all goes well, Kassabian hopes to deploy wireless gear in seven to 10 more locations by June.

Cisco got the nod because of its flexible management options, access security, and ability to set alarms and log error thresholds. What's more, the system provides a good view of signal strength and quality. But there's one drawback:

Cisco doesn't support Apple PowerBooks. For those, Kassabian says the Lucent PC card is the only real option. Still, the card isn't ideal for the Macintosh environment and often requires rebooting.

The university doesn't plan to use the Lucent access points. IT wasn't impressed with the Lucent product, primarily because it lacks a console port and because the management tools only run on Windows operating systems. While Windows is popular, many other operating systems are used on campus.

Penn worked with value-added reseller Armstrong Microsystems of Kittanning, Pa., to implement the Cisco wireless gear. Brent Hester, general manager of Armstrong Microsystems, says that of the products Penn tested, the Cisco access points and cards seem to provide the most versatility. "They are probably the most easily managed products for an enterprise wireless network," he says.

Hester says the Cisco wireless gear will let Penn provide mobile access to PennNet from anywhere on campus.

Room for improvement

Yet Kassabian notes that even his top choice could use some enhancements.

"The weakest feature of the management interface is the graphics," he says.

"Even in the Web interface, the graph uses ASCII symbols and the axes are sometimes severely misaligned. These graphs are not very readable, so most people will want to use some other network-management tool in order to view statistics for anything beyond a quick look."

In addition, IT would welcome Macintosh support in Cisco's PC cards.

While Cisco had a slight edge over most of the other products in terms of access control and traffic statistics, Kassabian says 3Com's AirConnect was a close second.

"We like 3Com's access point and site-survey tools very much, but we think the product needs a bit more maturity in the WEP and client OS support areas," he says. "We'll continue to work with AirConnect and may use it in the future."

One way all the wireless vendors could improve their equipment would be to use Remote Authentication Dial-In User Service (RADIUS) for authentication and authorization. Access control to wireless networks based on RADIUS would make for tighter integration and easier deployment, Kassabian says.

Harter is a freelance writer based in Athens, Ga. She can be reached at betsyharter@aol.com.

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