Protocol analyzers for LANs have been around for ages. As more enterprise networks move toward high-speed topologies using either ATM or Gigabit Ethernet, the need for protocol analyzers for both increases.

But life on the leading edge is never easy. And even though demand may be increasing, the technology still falls somewhat short when it comes to high-speed protocol analyzers. Our testing showed that ATM and Gigabit Ethernet analyzers as a class needs to mature. ATM analyzers lack expert systems support and both types of analyzers need much larger capture buffers.

In spite of these drawbacks, Wandel & Goltermann Technology's devices won by a small margin and took honors in the Gigabit Ethernet category. Each of the Wandel & Goltermann entries displayed excellent decodes and solidly built data-capturing pods that provide insight into both high-level and low-level protocol layers.

ATM analyzers from Hewlett-Packard Co. and Network Associates tied for second place, just behind Wandel & Goltermann's DominoATM. HP's Internet Advisor ATM has a well-rounded set of features while Network Associates' ATM Sniffer is exceptionally easy to set up and use. The fourth ATM analyzer in our roundup--GN Nettest's WinPharaoh--offers a solid capturing platform but lagged in usability, decodes and display filtering.

We feel confident recommending the top three entries in our ATM tests. Despite various shortcomings, each has definite advantages. However, if you need a protocol analyzer for Gigabit Ethernet you might want to hold off for a few months until more choices hit the market. Although Wandel & Goltermann's DominoGigabit is an excellent product, it may not be wise to buy so early in the game.