Building a bridge to DSL, Ascend fuses ISDN and DSL for new solution >BY BETH SNYDER, Associate Editor-News

Carriers are hungry for digital subscriber line technology. Spurred by the threat of cable modems and Internet-clogged voice switches, many are desperate for a solution.

So far, no commercial products exist, and most of the focus has been on the technology. The logistics of eventually rolling out service is relegated to a discussion somewhere down the road. But carriers do agree that they have to avoid the nightmarish and unsteady launch of ISDN.

This week, Ascend Communications plans to target carriers and Internet service providers with DSL service that leverages the rising tide of ISDN popularity and familiarity. The company has coined the term IDSL-connecting any ISDN modem at the customer premises to a DSL line card in the local access switch.

Using Ascend MAX WAN access switches, the company will offer MultiDSL with line cards that support not only ISDN but carrierless amplitude/phase modulation and discrete multitone asynchronous DSL as well as single-pair DSL. IDSL will provide 128 kb/s data access while SDSL will offer 768 kb/s, and both ADSL technologies will handle 1.54 Mb/s upstream and 64 to 176 kb/s downstream.

Ascend plans to offer IDSL line cards for the MAX as the first step to introducing carriers and their customers to DSL solutions (see table). The other important element is offering billing, accounting, network management and authentication services for DSL.

MFS Communications will be one of the first carriers to use Ascend's IDSL system. MFS is expected to announce service this week.

Other carriers, such as Bell Atlantic and BellSouth, should also be interested, said John Morency, director of the network industry practice for The Registry, a Newton, Mass.-based consultancy.

"This is focused toward the carrier community and specifically to those who are interested in aggressively rolling out DSL solutions," he said. "There is great scalability in the whole idea.

Ascend is the first data access carrier to focus on DSL and make room in its switches, Morency said, which may give it the advantage over competitors such as Cascade and Cisco StrataCom in being early to market.

That's exactly what Ascend officials are counting on.

"We are leveraging the benefits of ISDN. We strongly believe this is going to jump-start the DSL market," said Richard Sekar, Ascend product manager for high-speed access.

The company has already received strong interest from the carriers and ISPs. Four telcos-Pacific Telesis, U S West, GTE and SBC Communications-already use the MAX to offer customers Internet access.

"Our view is that DSL will be a significant player, but not until 1998," said Bernie Schneider, vice president of strategic business development at Ascend. "You'll see it building the end of '97. But you can't just move bits, you have to fit it in to existing systems. Long-term, this positions us to be a major player in the DSL market.