New wave rolls over metropolitan fiber nets

BALTIMORE - Announcements expected at the Optical Fiber Conference 2000 this week indicate it may be time to think about Gigabit Ethernet services between campus sites in the same metropolitan area.

Vendors are introducing carrier equipment they say can make it affordable for customers to buy up to 2.5G bit/sec services over metropolitan area fiber networks. For example, one vendor claims its gear could support a 100M bit/sec service for the price of a traditional 1.5M bit/sec T-1.

The new equipment from the likes of start-ups Astral Point and Chromatis, as well as Ericsson and other larger companies, introduces wave division multiplexing to metropolitan networks, which costs less than long-haul dense wave division multiplexing (DWDM). The technology puts multiple wavelengths of light onto a single fiber, boosting the capacity of the fiber by 2.5G bit/sec per wavelength.

That means an abundance of metropolitan bandwidth, which should translate into lower prices, says Raymond Keneipp, an analyst with The Burton Group in Charlottesville, Va. That extra capacity will also be used more efficiently than on traditional SONET rings because the new gear can cram more data on a wavelength with less overhead than SONET, he says. Most of the products being introduced are expected to ship later this year, and Keneipp says carriers could be offering services based on those products before year-end.

The new equipment integrates aggregation switches with the optical gear, making it easier for carriers to set up the connections customers want, says Scott Clavenna, principal analyst with Pioneer Consulting in Cambridge, Mass. "This speeds the introduction of distributed LAN services," he says.

Start-up Astral Point is introducing ON 5000, aggregation gear that connects lower-speed networks to optical links. ON 5000 can be fitted with hardware modules with ports as slow as T-1 ranging up to OC-48 that customers can plug into. The equipment can aggregate that traffic onto an OC-48 wavelength of light that travels across the metropolitan network.

If one fiber connection fails, ON 5000 can reroute traffic to another fiber with the resiliency of SONET, Astral Point says. Each ON 5000 node can handle up to 32 wavelengths of light per fiber. Once the equipment is connected to a fiber, filters can be added so it can remove and add wavelengths without disrupting existing services, the company says.

Chromatis, another start-up, is introducing Metropolis 2000, its local optical node that supports SONET, time division multiplexing and IP services. Metropolis 2000 can handle up to 32 wavelengths, but can be configured to handle just one 2.5G bit/sec OC-48, eliminating costly WDM components. That WDM equipment can be added later as needed. Service providers using Metropolis 2000s in office buildings could charge the cost of a T-1 for 100M bit/sec Internet access pipes and still turn a profit, Chromatis says.