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Neal Weinberg
Contributing writer, Foundry

Symbol WLAN switch

Opinion
Nov 06, 20032 mins
NetworkingWi-Fi

* The Reviewmeister wraps up his WLAN tour

A major differentiator between wireless LAN switches is the way they move traffic between the wired and wireless worlds. Every product we tested used a different tunneling method, making troubleshooting more difficult, and virtually ruling out interoperability.

All devices use standard 802.11 framing when moving traffic between wireless clients and an access point. From the access point to the switch, it’s a different story. Symbol encapsulates the entire 802.11 frame in a standard 802.3 Ethernet frame.

The list of tunneling types doesn’t end there; some vendors also use special methods to move traffic between WLAN switches. Here again, Symbol uses standard Ethernet framing to move traffic between switches.

All these different methods can pose challenges for network troubleshooting and management. When a problem occurs, firing up a protocol analyzer like WildPackets’ AiroPeek or EtherPeek is often the best way to figure out what’s wrong. But no analyzer will recognize, for example, Symbol’s 802.11-inside-of-802.3 tunneling, because it won’t expect a wireless header after the Ethernet header.

Security is an obvious concern with WLANs, and again there are big differences among products. When it comes to securing user traffic, all switches support the 802.1x specification for user authentication. We successfully authenticated WLAN clients through Symbol’s systems using Protected Extensible Authentication Protocol (PEAP). The switch acts as an authenticator, ferrying messages between the client and a RADIUS/PEAP server.

Support for 802.1x authentication carries another benefit by changing the keys used for Wired Equivalent Privacy (WEP) encryption at frequent intervals. That’s important because WEP design is inherently weak, and an attacker possessing a static key can decrypt traffic with relatively little effort.

All switches add various security measures above and beyond those furnished by the WLAN protocols, although the offerings are mixed. Symbol  is strong on access control, and has the most awareness of power savings for handheld devices.

For the full report, go to https://www.nwfusion.com/reviews/2003/0922rev.html