Wireless Lan

(02/05/2001) – While this may be the fourth or fifth straight year you’ve heard this, it’s finally the year of the wireless LAN.

With the acceptance of the 802.11b standard, a number of products and vendors have hit the market with access point products for the enterprise. We tested nine wireless LAN access points: the Buffalo Airstation from Buffalo Technology Inc.; the Aironet 340 from Cisco Systems Inc.; the DWL-1000 AP from D-Link Systems Inc.; the RoamAbout Access Point 2000 from Enterasys Networks Inc.; the Intel Pro/Wireless 2011 Access Point from Intel Corp.; the Intermec 2102 Universal Access Point from Intermec Corp.; the Orinoco AP-1000 Access Point from Lucent Technologies Inc.; the Harmony 802.11 Access Point and Access Point Controller from Proxim Inc.; and the Spectrum 24 11M bps Access Point from Symbol Technologies Inc.. Breezecom Inc. accepted our invitation, but could not send us the equipment for our tests in time to be included in the review.

To fit into an enterprise network, performance is essential, but it’s not enough by itself. You also want manageability, stability and security. Anyone who has managed large and small LANs knows that what works in a small office, home office (SOHO) environment doesn’t always scale well into a company. Several vendors sent us very good SOHO equipment that we would have severe reservations about in a larger environment. Also, some enterprise gear was lacking in performance.

In the end, despite a higher price, the Cisco Aironet 340 series equipment delivered the best mix of performance and manageability and won our World Class Award.

D-Link, while not truly delivering enterprise-class hardware, offers an extremely good price/performance ratio and gets an honorable mention in a SOHO environment. Proxim offers some stunning management tools, but its product’s performance was the lowest of any of the enterprise-class access offerings. Enterasys and Lucent offer good tools, good performance, but their range isn’t on par with Cisco’s. The Intel and all-but-identical Symbol equipment fell a bit short on management tools.

How fast is it?

We spent a lot of time benchmarking our 802.11b networks, and the findings are interesting. In all the tests we ran, four nodes could saturate the network. An access point is comparable to a 10M bps Ethernet segment, so you can use pretty much the same guidelines you use for 10Base-T loading to govern 802.11b loading.

We were surprised to find such a wide spread of data transfer rates between the products. Depending on the test, some network interface cards (NIC) were almost twice as fast as others, and some access points were as much as 50 percent faster than others.

Statistics showed us that 100M bps Ethernet was between 10 and 20 times faster than the 802.11b network components, depending on the wireless vendor and the test we were running. One thing our benchmarks don’t show is what happened to the rest of the network while the benchmarks were running. At one point, we ran the usual office automation tasks during the testing on 100M bps Ethernet and the wireless LAN. With the 100M bps Ethernet, the tasks ran at an acceptable speed.

With the 802.11b network, things crawled to a stop while the benchmarks were running. In short, the wired Ethernet had more headroom. Again, that shouldn’t be a surprise.

We were disappointed by the performance of Proxim’s Harmony. Proxim has taken an interesting approach with Harmony, making its access points “dumber” and putting the intelligence into the Harmony Access Point Controller. With the intelligence in the controller, you automatically get a single point of control. This lets you control many more access points (Proxim recommends 10, although it can handle more), and also lets you have access points based on different technologies. The “dumb” access points also are less expensive than those of the other enterprise-class vendors. Several are cheaper, such as the

D-Link and Buffalo, but they aren’t in the same league.

It was never clear to us why the performance of the Proxim Harmony lagged. The system design means that all Harmony wireless traffic crosses the wired network twice, but Proxim assured us that wasn’t usually a bottleneck, and a bit of math suggests that doubling the traffic of an 802.11 link is still less than 20 percent of the capacity of a 100Base-T network.

Security options

The 802.11b standard offers several layers of security. At the lowest level is the System ID, also known as the Electronic System ID, SSID or ESSID. This is an identifier code the system manager enters into the setup of all the access points and NICs that will participate in the network. By default for all the vendors except Intel and Symbol, you can enter the word “any” into the NIC setup, and the PC can participate in any network. This makes it easy to get a wireless network running, but offers no security. Even if the “any” option is disabled, it isn’t hard for someone to look up the ESSID and use it later