Talking Digits

Occam slices through VoDSL complexity

If the cost and complexity of the customer premises equipment needed to make voice-over-DSL happen are a hindrance, then the folks at Occam Networks have an idea: Get rid of it.

Today, VoDSL service uses an integrated access device to convert voice into packets on the customer premises and to send those packets out over the DSL connection. The most popular IADs come from Efficient Networks and Netopia.

The problem is that the ballpark cost of a standard IAD — about $700 — is difficult to justify in this tight telecom economy, and deploying the box, especially for consumers, is far more complex than installing a standard DSL modem.

Occam, which takes its name from William of Ockham, the 14th-century theologian whose "keep it simple" philosophy became known as Occams Razor, has developed a platform that moves the IAD functions to the remote terminal or central office, "simplifying" the network, says Jim Soriano, the companys vice president of engineering.

"Once you put an IAD at the customer site, you are introducing complexities in management," Soriano says. "We believe the customer presence equipment needs to be as simple, cost-effective and straightforward as possible."

Occam developed a box it calls the Occam Broadband Loop Carrier (BLC) that is in the same category but a step ahead of todays "next-generation" digital loop carriers (DLCs), including those designed by Advanced Fibre Communications and Alcatel.

These next-gen DLCs are designed to carry broadband as well as voice communications in one box that can fit in the tight, weather-hardened spaces of remote terminals. However, Occams BLC takes the concept a step further, adding the ability to convert standard voice communications to Internet Protocol packets, which can then traverse an IP backbone and take advantage of advanced IP applications.

"If a service provider wants to provide value-added services, then our box is very much in their sphere of influence," Soriano says.

The first iteration of the BLC isnt due until the third quarter, but Occam has several trials in progress with rural telephone companies.

"The equipment is still in test mode, but as far as the voice side is concerned, packet voice is something were pretty much committed to. And [the BLCs] ability to do that is important to us," says Jim Noel, director of The Armstrong Group of Companies. Armstrong owns and operates six telephone companies, servicing 20,000 lines in Maryland, New York, Pennsylvania and West Virginia, as well as several cable television franchises, and is conducting lab trials of the BLC. "Were looking at this from a standpoint of getting ready for the next-generation [packet] switching environment," Noel says.

To perform VoDSL without a solution like Occams would mean not only installing IADs for every customer, but also placing VoDSL gateways in every remote terminal fed by fiber, since DSL on its own cant be transmitted over fiber loops. Occam converts the voice into IP, so it can traverse any backbone: fiber, copper, broadband wireless, whatever.

Rural Telephone, a telecom co-op in northwest Kansas, is using the BLC primarily to offer DSL where previously only limited services were available, says Shane Broyles, Rural Telephones research and development director.

Rural Telephone first began providing service to employees, but the company now has a few paying customers.