Ten years ago, Bellcore engineers were digging into Digital Subscriber Line technology as a means of carrying video into the home. Four years ago, equipment vendors that saw the Internet bury the video-on-demand market were touting Asymmetric DSL as the perfect means of providing faster data services.
And this year, DSL quite suddenly has become a method of transporting multiple voice lines on a single physical phone line. The voice-over-DSL market seems to be taking off so fast, in fact, that it may be a significant competitive force within the next six months.
"A hundred years from now, when historians look back at this point, 1999 is when it began to happen," says Kevin Walsh, vice president of marketing at Accelerated Networks, a maker of integrated access devices combining voice and data in Asynchronous Transfer Mode signal that traverses DSL access links. "We are seeing a lot of [competitive carriers] begin deployment phases as we speak."
Those who have traced DSL's history find reason for caution whenever anyone expects anything to happen quickly. "There is a great deal of interest in voice-over-DSL, but it has yet to be proven on any large scale," says Frank Wiener, vice president and general manager of DSL at Paradyne, one of the earliest Asymmetric DSL vendors.
Yet, the positive indications are many. The three major national DSL network providers - Covad Communications, NorthPoint Communications and Rhythms NetConnections - are testing voice-over-DSL technology with an eye toward deployment in late 1999 or early 2000.
One regional competitive local exchange carrier (CLEC), Picus Communications, already started commercial deployment of voice-over-DSL equipment in Virginia, with plans to move up the East Coast.
The three major purveyors of voice-over-DSL gear - CopperCom, Jetstream and TollBridge Technologies - have forged partnerships with virtually every maker of DSL network equipment. Other companies, such as Accelerated Networks, have launched integrated access devices that also function over DSL links and combine voice and data with other features. Lucent Technologies has jumped into the fray with the Stinger, its first DSL network gear, designed to support voice and data.
"We believe this market is taking off like wildfire," says Jennifer Stagnaro, vice president of marketing at CopperCom.
Many CLECs are targeting small and midsized businesses, which are viewed as underserved by incumbent telephone companies. International Data Corp. says 7.4 million companies with fewer than 100 employees use 12 or fewer telephone lines but spend almost $50 billion per year on local and long-distance services.
"If CLECs can add voice services to their repertoire, using the same DSL access line that they use today to provide higher-speed Internet access, then they can generate significant new revenues," says David Lively, voice-over-DSL product manager at Cisco Systems.
That market segment is moving so fast that voice-over-DSL will soon be table stakes for companies that want to be national DSL network providers, says Jim Greenberg, chief technical officer at Rhythms, which expects to have commercial product by year's end.
There has even been mention, in standards meetings and engineering discussions, of incumbent telephone companies using DSL to transport multiple voice services to homes in neighborhoods where demand for extra lines exceeds available copper.
"It makes economic sense," says George Hawley, CTO at Nokia's High-Speed Access group."There are places today where the telephone company faces copper exhaustion."
Before any residential market for voice-over-DSL can take off, a new generation of customer gear is needed. Today's systems add up to 16 phone lines per pair of wires, and they would be overkill for a home network, says Wiener, whose company last year worked with AG Communications on Superline, a multiple line system.