Nortel's Measured Response

In an attempt to find a better way to compare the raw performance of optical transport equipment, Nortel Networks recently started using a new metric called bandwidth reach.

Although the call for the use of a new benchmark has the look and feel of a marketing ploy to attract attention to recently released DWDM gear, Nortel officials say that the industry needs a tool to compare products as equipment grows more diverse.

"We think it's important that service providers look at this metric," says Benoit Fleury, director of solutions marketing at Nortel's Optical Internet division. "It gives you a more direct link between the capabilities of a system and the overall costs."

Bandwidth reach is determined by multiplying three attributes of a dense wavelength division multiplexing system: the number of wavelengths it can support, the bit rate of those wavelengths, and the distance a signal can travel without electronic regeneration.

Using that formula, Nortel claims a rating of almost 5 petabits (that's 5 quadrillion bits) for its recently announced OPTera Long Haul 5000 system, which will be capable of sending 104 separate wavelengths of 40 gigabits per second over a distance of 1,200 kilometers, according to Nortel.

Industry analysts speculate that the introduction of the new metric could be a starting point for dealing with some of the performance trade-offs associated with stretching the reach of optical capacity. Andrew McCormick, an analyst with the Aberdeen Group, notes that in most cases, the overall capacity of a transport system decreases in proportion to the distance of optical spans. Bandwidth reach "would be a benchmark for comparing apples to apples," McCormick says.

For the most part, competing optical equipment suppliers aren't impressed by the new metric. Officials from Lucent Technologies and Sycamore Networks say the bandwidth reach metric is at best a rudimentary tool for evaluating hardware.

Nortel's Fleury appears to agree with that criticism. "It's a good first indicator," he says. "But you have to look at a lot of things."

Copyright © 2004 Ziff Davis Media Inc. All Rights Reserved. Originally appearing in The Net Economy.