VoIP over cable rolls out, viability still questioned

Marking a major step for a cable operator, Time Warner Cable announced last month it is delivering voice over IP over cable (VoIP over cable) to its residential customers in Portland, Me. with the help of Cisco Systems Inc.

Time Warner is now offering customers a bundle of services, including voice, video and Internet access, which lays the foundation for future service offerings like video telephony and multi-player online gaming. Called Digital Phone, the service enables Time Warner Cable to offer local and long-distance calling over cable at a flat rate, saving customers a pretty penny.

The announcement also marks the first production deployment of Cisco’s cable VoIP solution. The San Jose-based network gear maker has announced new offerings that recently obtained PacketCable 1.0 Call Management Server (CMS) as well as Data Over Cable Service Interface Specifications (DOCSIS) qualifications. DOCSIS is a set of standards for transferring data via cable TV and cable modems; PacketCable 1.0 specification defines the protocols and network interfaces required to provide IP voice services.

Standards-certified, the Cisco BTS 10200 Softswitch cable modem termination system and the MGX 8850 voice gateway are the building blocks of the Cisco Broadband Local Integration Services Solution (BLISS) for cable, the company said. The products enable cable providers to deliver IP-based voice services over their existing DOCSIS IP networks.

“Our customers are asking us to define the edge of their networks in cable-land in this very intelligent, very resilient device,” explained Paul Bosco, vice-president of broadband/cable development with Cisco in Boston.

While the Time Warner Cable service is designed for residential use, Cisco said enterprises also might adopt VoIP over cable. Bosco noted that in the past six months, there has been a significant upturn in major corporations inquiring about VoIP over cable for remote VPNs and home access networks for teleworkers.

“The cable guys are getting smarter and are beginning to bundle data services for the SOHO (small office, home office) market,” Bosco said. “This is setting the stage for cable companies to handle the voice services as well.”

EastLink, a Halifax-based maritime cable service operator, has been offering voice over cable for nearly four years and has the technology widely deployed throughout Nova Scotia and P.E.I. EastLink’s service is based on a 64-bit circuit-switched network, rather than the packet switching employed in VoIP. The firm believes voice over cable has a place in the Canadian market, but does not see the value in using IP, according to David Caldwell, EastLink’s senior director of business services.

“[VoIP] really doesn’t have the cost-advantage that people are hoping for,” Caldwell said, adding, “Voice over cable on a circuit-switched network is proven technology.”

Industry experts also remain skeptical of VoIP over cable. Roberta Fox, president of Markham, Ont.-based Fox Group Consulting, said the technology is too unstable for the enterprise.

“We actually got rid of our high-speed cable Internet because it became unusable after 4 p.m.,” Fox said. “The cable carriers have not invested enough in the infrastructure to make it VoIP-grade.…The cable network is not built to support enterprise needs.”

Cisco’s Bosco disagreed.

“Five years ago, people were saying they would never let a cable guy touch their PCs, and four years ago it was that cable operators would never be able to run an IP network,” he said. “I think we are seeing the next step that proves the cost-effectiveness and the high availability the cable companies are able to provide.”