It's metro time for DWDM.

Local exchange carriers that have been waiting to test drive metro DWDM can start their engines.

Dense wavelength division multiplexing (DWDM) has made a home in the nation's long-haul fiber optic networks. There's no question it's needed there, as it would cost millions to lay new fiber to meet increased demand. But what about the metro area? Will there soon be enough data traffic waiting at the edge of the network to make it more economical to use DWDM in the metro area for data networking purposes?

In 1999, competitive and incumbent local exchange carriers (CLECs and ILECs) will begin kicking the tires of ring-based metro DWDM systems. The new systems will offer optical layer protection switching, which will make them particularly suited for the optical transport of higher- than-synchronous optical network (Sonet) speed data across and within the local metropolitan area. Carriers that have been wanting to build local networks minus expensive Sonet gear now can do so.

Established Sonet/optical network operators are already rolling out or preparing to roll out their metro DWDM systems which, they say, will move the industry a giant step closer to the all-optical future. Meanwhile, startups such as Monterey Networks (Richardson, Texas) and Sycamore Networks (Tewksbury, Mass.) are pooh-poohing the need for rings in the metro or long-haul environments; they say wavelength routers used in mesh network topologies are a better way to provide optical layer protection than it would be by going to the trouble of deploying bidirectional line switched ring (BLSR) or unidirectional path switched ring topologies (UPSR), which the incumbent suppliers are encouraging them to build.

At press time, both companies had revealed the concepts behind their soon-to-be-released products. However, they had not yet divulged specific details about them. Incumbent optical network vendors shrugged off …