Voice Over DSL Talk of the Town
- 10 April, 2000 12:01
SAN JOSE, CALIF. (04/10/2000) - If demonstrations from last week's DSLCon show are carried over into the real world, corporate customers will be able to turn common phone lines into high-speed voice-data circuits with ease by year-end.
Forthcoming voice-over-digital subscriber line (DSL) services will be able to replace the multiple individual phone lines and T-1 circuits that branch offices use today to carry voice calls, experts say. And broadband Internet access can ride the phone line at the same time.
Vendors, such as Jetstream Communications, are planning products that enable advanced voice-over-DSL services such as call forwarding and customizable DSL services.
At the show, makers of DSL gear proved they could run up to 14 voice channels plus hundreds of kilobits of data on a copper phone line connected to real-world phone networks. They were successful with equipment from several firms, not relying on just one vendor's scheme.
The demonstrations took vendors beyond their past practices of simply announcing DSL boxes that wouldn't interoperate with equipment made by others and put voice-over-DSL services on a reality track.
Customers soon will be able to buy voice and data services from a single carrier, have them delivered via one circuit and pay up to 40% less, some service providers say. Voice-over-DSL vendor MCG Communications in Phoenix offers a bundle of 10 voice lines, 'Net access and 500 minutes of long-distance for about $500 per month, roughly the recurring cost of a T-1 line.
While sales of such services today are negligible, they are set to skyrocket in the next few years, analysts say.
To prove the technology is ready, service providers Focal Communications and Northpoint Communications teamed with equipment maker CopperCom to run multiple voice channels on their nets. Covad Communications held a demonstration with service provider GST Communications and hardware vendor Jetstream. Covad is also delivering voice-over-DSL services in field trials, with full rollouts expected in the second half of the year.
Rhythms Netconnections, a major nationwide DSL service provider, didn't demonstrate voice over DSL at the show, but plans to offer the service by year-end, says Catherine Hapka, Rhythms chairman and CEO.
Some vendors are so sure voice over DSL is about to take off that they are going beyond building the carrier network DSL boxes and are making customer site equipment as well to jump-start use of their technology.
Copper Mountain, which is focused on making DSL concentrators that funnel customer DSL lines into service providers' nets, introduced the CopperRocket 408 symmetric DSL integrated access device. The box enables voice over DSL by turning voice into IP packets and cramming them in among the IP data stream. At the same time, the box ensures that voice packets get top priority so the quality of the voice service is as good as that on the public phone network.
TollBridge makes a customer premise switch that converts IP voice to traditional circuit-switched voice and passes it along to the phone networks.
Most DSL providers rely on ATM, not IP, to carry voice and data traffic across DSL links because ATM is the most reliable technology today for imposing quality of service on different traffic types.
Alcatel, which sells much of the U.S. carrier DSL gear in use today, is selling CopperCom voice-over-DSL gear until it produces voice-over-DSL boxes of its own.
While voice over DSL was the sexiest application at the show, vendors are already looking for others. For example, Jetstream plans to announce at SuperComm that its CPX-1000 voice gateway will enable new types of phone services for packet-based carriers to offer.
Jetstream will do that in two ways. First, the company will add software to its device to create the new services, such as forwarding calls to a different number after four rings, then dropping calls into voice mail if no one answers at the second number.
The firm will then add software that makes it easier to access calling features that already exist on Class 5 local voice switches. Most of the applications that Class 5 switches support are not sold to customers because it is too difficult to provision them, says Stephen Gleave, Jetstream's vice president of marketing. The goal is to make it possible for customers to build their own caller profiles via a Web browser. They will be able to add and drop features without waiting for the service provider to do it.
In other events, Texas Instruments showed for the first time a voice-over-DSL prototype network to be used by service providers and equipment makers that want to write specifications for or build their own voice-over-DSL gear.
Nevertheless, for all the optimism at the show, the technology still faces shortages of components, particularly chips, that could slow deployment if demand spikes before component vendors increase production.
"We've hit a little of a supply shortage, but availability is already at a sufficient level to ensure growth," says Bill Rodey, vice president of sales and marketing for DSL vendor Westell and treasurer of the DSL Forum.
The problem is being resolved as chip makers prove their chips are interoperable. That means makers of complete DSL modems and multiplexers don't have to rely on one chip vendor for the silicon they need to build their products. Multiple sources should also drive down prices, Rodey says.