Voice over DSL reigns again

Simple high-speed access and myriad DSL offerings are not enough to provide healthy revenues or keep customers. Voice over DSL is the logical next step toward a more complete service offering.

Some customers may not have enough traffic to demand a T-1 line, but with DSL, their need for speed can be satisfied at a lower cost. Voice-over-DSL vendors aim to convince service providers of the technology's toll-grade quality and scalability. The results are mixed.

Competitive local exchange carriers (CLECs), anxious to bite into incumbents' market share fall into the early adopter category. But larger carriers, most of which already provide voice services, want to wait out the initial phases.

"We are testing the voice-over-DSL technologies and working with Rhythms [NetConnections], but we are not ready to deploy the technology," said an MCI WorldCom spokesman.

But for customer-hungry CLECs, time is not a commodity. Atlanta-based service provider Edge Connections is deploying equipment from AccessLan Communications and its partner Jetstream Communications to provide an immediate inroad to multitenant units in Atlanta and New York.

"We can literally be in a building in two hours," said Ben Petro, vice president of marketing for Edge Connections. "We don't need to do drilling or rip out and replace wiring. All we have to do is stack the boxes in the basement, connect to existing copper wires and go."

Because the equipment is unobtrusive, it's easy to negotiate agreements with building owners, Petro said. Such simple and fast access is intended to give Edge Connections a leg up on the competition, which typically is installing new wiring and a DSL access multiplexer in the basement of buildings.

"With 75% of multitenant buildings not qualified for DSL, that leaves an extreme opportunity for us to tap enterprises and small to medium-sized businesses," Petro said. Bandwidth in the enterprise arena is expected grow steadily (see figure).

Cost and the variety of enabled services are also an attraction. "The economics are incredible," he said. "If we light up only two to three tenants [in a building], the equipment has paid for itself."

Beyond economics and ease of installation, AccessLan can deliver an integrated product set as perhaps the biggest bonus, Petro said. "High-speed access alone is not going to cut it."

Another vendor tapping into the voice-over-DSL craze is Accelerated Networks, which recently won a contract with Primary Network Communications. This week, Accelerated plans to reveal a new standard submitted to the DSL Forum, called "switched voice over DSL," said Kevin Walsh, vice president of marketing for Accelerated.

Under the proposed standard, voice over DSL will use switched virtual circuits (SVCs) rather than nailed-up permanent virtual circuits (PVCs), which don't allow for scalability, Walsh said. "By using switched voice over DSL, providers can bypass Class 4 and Class 5 switches entirely, which has a lot of economic advantages."

"It will give service providers a lot more flexibility than what they have had in the past," said Christin Flynn, an analyst with The Yankee Group.

But not all agree. "We don't think you should rely on PVCs or SVCs. We believe a dynamic virtual path should be created," said Kumar Shah, vice president of marketing for AccessLan. "The ATM SVC model doesn't scale and lacks end-to-end quality of service requirements."