Shedding new light on dark fiber

by Michael Martin

March 14, 2001 —

Enterprise customers are finally seeing the light when it comes to obtaining huge chunks of bandwidth in campus and metropolitan-area networks. Large organizations now have the option of getting out of the business of leasing and lighting dark fiber themselves, and moving to multigigabit wavelength services managed by service providers.

There are several reasons for looking at making the shift, but chief among them is ease of management.

Large enterprise customers first began leasing dark fiber from service providers in the early 1990s. Their data needs were exploding, and the SONET and ATM services offered by carriers were expensive and not very efficient at transporting protocols such as Enterprise Systems Connection, Fibre Channel and Ethernet. So instead of paying for traditional carrier services, large companies -- especially financial institutions -- began leasing chunks of fiber between their facilities, lighting the lines with their own switches and managing the fiber connection end-to-end.

But the recent advent of dense wavelength division multiplexing (DWDM) and its growing presence in MANs has the potential to lessen the appeal of leasing dark fiber in this manner.

DWDM multiplies the bandwidth potential of fiber many times over by allowing a single fiber strand to carry multiple wavelengths of light. For instance, Nortel Networks' OPTera Metro 5000 series optical platforms can carry up to 64 wavelengths across one fiber ring.

Managed wavelength services are available from a variety of service providers, including 360networks, Metromedia Fiber Network, Level 3, Global Crossing, XO Communications and AT&T. While the service price will vary depending on fiber availability and the exact services ordered, all these firms are looking for very large customers that will sign long-term contracts worth millions.

For example, AT&T expects customers who sign up for its recently announced DWDM-based Ultravailable Broadband Network service to spend between $10 million and $100 million over the course of a five-year contract. Ultravailable Broadband Network provides metropolitan-area connections at up to 2.4G bit/sec.

Other firms, including Cogent Communications and Yipes Communications, offer Ethernet services over optical wavelengths aimed at smaller businesses. Cogent's services begin at $1,000 per month for a 100M bit/sec Internet connection. But Yipes' and Cogent's services don't provide the same bandwidth or service-level agreements that providers are targeting at larger companies.

GiantLoop Network, a Waltham, Mass., service provider, offers optical and professional services to Fortune 250 companies, focusing specifically on financial institutions. Although GiantLoop doesn't own any fiber, the company will obtain fiber for its customers, light it and manage the customers' networks. The firm supports several protocols running across optical wavelengths in metropolitan, campus and intercity networks.

Jon Oltsik, GiantLoop's vice president of corporate marketing, says there are a number of advantages to a company choosing an outsourced, managed wavelength service, rather than setting up its own dark fiber network or buying SONET services.

One is ccost. If a firm wants to run its own services over dark fiber, it must pay for a dark fiber lease, switches to light the fiber, management platforms and specialized personnel to run the network. The optical expertise required to run wavelength services over dark fiber is difficult to find and expensive, Oltsik notes, so many companies would rather not run their own wavelength services.

Another advantage is simplicity, Oltsik says. Optical wavelengths let protocols be transported in their native formats with no conversion required at either end of the connection. Companies also might find it difficult to engage in negotiating long-term leases on fiber routes, which is an art in itself, he adds.

"You end up getting into areas where the skill sets of your IT people are very limited," Oltsik says.

Another advantage wavelength services have over dark fiber and traditional SONET services is that they can be deployed quickly, Oltsik says. If a customer needs more bandwidth, all a service provider has to do is add another wavelength by placing a new line card in the carrier switch -- not more bulky equipment and fiber.

"When you order services from us, you're not losing any time compared to what you'd be waiting for with SONET," Oltsik says. "But when you need more bandwidth, for us to put that up, it's a matter of days, rather than the weeks or months new SONET services can take."

Still, the question of whether a company should forsake dark fiber for managed wavelengths isn't an easy one to answer, says Rosemary Cochran, principal with research firm Vertical Systems Group.

"It's not easy to do a comparison of what it will cost to do it yourself and what it would cost for a service provider to do it for you," she says.

Certainly no company that's already operating its own dark fiber network is going to shut its network down until it has to do so, Cochran says. Reasons for moving to a managed service might include new applications, a shortage of bandwidth or difficulty retaining qualified IT staff, she says.

Another factor weighing against moving to a managed wavelength service is that many of the providers offering them are not traditional incumbent local exchange carriers. Some providers sell only on a wholesale basis, while others have offerings aimed at large enterprise customers.

"These services are offered mostly by start-up service providers, and no one wants to make a move that may be a risk," Cochran says.

Even though it may be more expensive to use a combination of dark fiber and SONET services from traditional carriers, many companies will want to stick with the tried and true, rather than taking a chance on an unknown entity.

"If it ain't broke, they likely aren't going to try to fix it," Cochran says.

Large companies aren't the only customers flocking to wavelength services. In fact, the biggest consumers of such services are carriers, ISPs and application service providers that buy wholesale bandwidth from other service providers.

"A lot of large carriers are looking at waves," says Sunita Krishna, a product manager at Williams Communications, a bandwidth wholesaler in Tulsa, Okla. "They want to focus on the IP layer, and they want us to focus on the optical layer."

Network World