Doubling up: DSL bonding doubles speed, reach of broadband technology

Entering a new market to provide DSL can become a painful adventure for an ISP simply because some potential customers may be dissatisfied. When it comes to solving the DSL distance problem, the daunting task of satisfying everyone is like searching for the golden ticket hidden inside a mountain of Wonka chocolate bars.

For small and medium-sized businesses, the bandwidth and financial gap between a fractional T-1 and ISDN DSL's (IDSL's) 128 kb/s runs far and wide. Netopia hopes to fill that gap with a new technology called DSL bonding.

Based on multilink point-to-point protocol, DSL bonding allows an ISP to aggregate multiple DSL links into a single, high-speed virtual pipe without requiring the ISP's carrier to upgrade its systems or reconfigure the central office (CO), said Barbara Tien, director of product marketing for Netopia. Currently, Netopia's equipment can aggregate four IDSL links; equipment that can aggregate two symmetrical DSL (SDSL) or asymmetrical DSL (ADSL) circuits will be available by the third quarter, she added.

With the bonding technology embedded in Netopia's R-series routers, an ISP can provide DSL service at speeds two to four times faster than traditional offerings and at distances up to 6.8 miles from the CO, twice as far as the common 18,000-foot limit. Customers with 1.5 Mb/s SDSL connections can achieve rates greater than 3 Mb/s, or twice as fast as a T-1 connection.

"It puts the power to do the aggregation in the ISP's hands and gives them a competitive advantage," Tien said. "ISPs can now enter a market and offer the speed that makes the most sense for the customer. They can satisfy everybody."

Florida Digital Network, an integrated communications provider that merged with Cavalier Telephone and Conversent Communications to form Elantic, tested the DSL bonding router and plans to roll it out shortly, said Jim DaBramo, vice president of sales and customer service for Florida Digital Network.

"It fills the void where ADSL is not available and IDSL's 128 kb/s is not enough bandwidth," he said. In Florida, where continuous copper is hard to get, Florida Digital Network could reach only 30% of businesses with ADSL, DaBramo said. But by bonding up to four ISDL circuits, the service provider can provide 576 kb/s rates as far as seven miles from the CO, he added.

The DSL bonding technology may have hit the sweet spot for service providers: business customers that need something between a T-1 link and basic Internet service, said Matthew Davis, senior analyst for The Yankee Group. Plus, if an ISP can reach customers that aren't able to get other solutions, it puts an "arrow in their quiver," he said. "Small to medium-sized businesses have a real need for some type of broadband access."

To implement DSL bonding, the service provider must deploy Netopia's router. Incumbents charge ISPs about $18 per line. Netopia's system can support up to four lines, bringing the total cost at most to $1267 per customer including equipment.

T-1 links cost customers about $1395 per month, including local loop charges.

The cost of getting the additional loops from the incumbent could hinder the technology's adoption. "If it gets more expensive, a T-1 could be a better solution," Davis said.

On the other hand, the bonding solution could act as a bridge between existing and higher-speed access methods. "ISPs can capture the business customer with the promise of swapping out a more robust SDSL solution," Davis said.