DSL: Three little letters that spell big savings on frame relay

By Tim Greene
Network World, 06/28/99

Are you shelling out $500 per month or more per T-1 line for frame relay access services?

You could save money by choosing a carrier that uses digital subscriber line (DSL) technology to deliver the service.

US West's !nterprise division last week introduced a service that saves customers $95 per month, per line, by using ISDN-based DSL instead of a T-1 circuit to access !nterprise's frame service. !nterprise is the data network and product development arm of US West.

Saving money
For customers who want more than 56K bit/sec but less than T-1 frame relay, U.S. WEST's -wire, 128K bit/sec Frame Relay service is cheaper than buying a fractional T-1 service.

Product Ac-
cess fee 5 vir-
tual cir-
cuits Total

2-wire 128K $35 $109 $144

Fract. T-1 at 128K $117 $122 $239

The service, called 2-wire, 128K bit/sec Frame Relay, establishes a 128K bit/sec access link between the customer and his 56K or 64K bit/sec frame relay network. The service more than doubles the access bandwidth for customers who have 56K bit/sec frame access service, and eliminates the need for them to buy a full or fractional T-1 service when they need additional bandwidth.

Separately, national long-haul data carrier Intermedia Communications plans to use multiple DSL flavors, in combination with special links to other carriers' networks, to cut hundreds of dollars per month from customer access bills.

Until now, carriers have been offering DSL mainly as a means of Internet access. But they are now looking to DSL technology as a way to circumvent costly T-1 services.

In the past, customers who wanted to boost frame relay bandwidth above 56K bit/sec had to buy a fractional T-1 access service. Thus they were paying for a circuit that can carry 1.5M bit/sec worth of traffic, but they were using less than that capacity. US West's service lets customers buy less capacity for less money.

Intermedia, meanwhile, is testing the use of symmetric DSL (SDSL) at 768K bit/sec and two-wire high-bit-rate DSL (HDSL2) at 1.5M bit/sec to support frame relay access.

In addition to using less expensive DSL access lines, Intermedia is taking advantage of the Network-to-Network Interfaces (NNI) it has between its network and those of the major local carriers, including all the regional Bell operating companies.

The NNIs let Intermedia use every RBOC switching office as a point of presence (POP) for Intermedia's network. That makes Intermedia access points closer to customers, eliminating the mileage fees customers would have to pay to reach separate Intermedia POPs, says Gerald Sharp, Intermedia's senior director of architecture.

Those mileage fees could amount to $400 per month per access circuit that Intermedia would pass along to customers, he says.

DSL frame relay access is already saving money for customers of Freeze Notice Weather, an ISP in Des Moines, Iowa. Freeze Notice normally runs T-1 lines to customers who need more than a 56K bit/sec frame relay connection to the Internet, says B.J. Bowman, systems administrator for the ISP.

But using US West's 128K bit/sec service gives the company extra bandwidth for $90 per month less, he says. He expects the number of fractional T-1s that Freeze Notice buys to drop because the company will instead buy more of the 128K bit/sec service.

Paradyne, which makes DSL gear, says DSL is a good option in areas where T-1-grade copper loops are scarce. Many varieties of DSL run on two wires instead of four, as T-1 does.

Paradyne is so optimistic about DSL as a frame access technology that it is developing a DSL modem with a frame relay interface that also monitors the performance of the virtual circuits running on the DSL line.

The device would let customers monitor the performance of the circuits to make sure service providers meet service-level agreements, says Scott Eudy, Paradyne's vice president of network access products. The product would be a marriage of Paradyne's Hotwire DSL modem and its FrameSaver DSU/CSU probe, he says.

"Most frame relay is for client/server applications. You need a little bit of bandwidth from the client to the server and a lot of bandwidth from the server back to the client," says Steve Taylor, principal at Distributed Networking Associates in Greensboro, N.C.

Taylor says that using DSL for frame relay access could drive down access costs. Service providers that use DSL for Internet access charge $50 per month for 256K bit/sec IP access. Customers will realize that they should pay roughly the same amount for frame relay access over the same type of DSL link, and they will pressure carriers to drop their prices, he says.