Analysts had expected that 2001 was to be the year IP voice over cable got under way. But vendors and their customers now say that goal is still a year away.
Telecom's heightened caution has combined with failed early attempts at service launches and other technical and logistical problems to delay the long-awaited move to VoIP, industry participants say.
Most important, perhaps, is that the next-generation modems, vital to delivering the quality-of-service parameters voice demands, have taken longer to come available than anticipated.
As of mid December, Cable Television Laboratories Inc. (CableLabs) indicated only two vendors, Texas Instruments Corp. and Toshiba Corp., had won certification for their DOCSIS 1.1 (Data Over Cable System Interface Specifications, version 1.1) modems. And this was two years after the specifications were set, and a year beyond the time many engineers had anticipated such modems would pass muster.
"I think the industry is still extremely interested in moving to VoIP, and there will be some new service additions and trials in 2002," says Mitch Auster, vice president of product management and marketing for IP cable telephony at ADC Telecommunications Inc. "But the big ramp up year is probably going to be 2003."
ADC has developed a unit for the cable headend, known in DOCSIS terminology as a CMTS (Cable Modem Termination System), that supports 1.1 modems and can be transformed with circuit cards easily into a full voice support system that acts as media gateway, media gateway controller and GR-303/V5.2 gateway.
Auster says ADC's customer list for its Cuda 12000 CMTS includes Adelphia Commu nications Inc., AOL Time Warner Inc. the AT&T Broadband unit of AT&T Corp., Cox Communications Inc., and German cable operations of U.K.-based Callahan Associates International LLC.
So far, only Time Warner, in its long-running second-line trial in Portland, Maine, and Callahan are using the system to support delivery of voice services, Auster says.
Perhaps the most significant cable VoIP deployment at this point is Callahan's over the former Kabel NRW, now ISH, cable properties in the North Rhine-Westphalia region, encompassing 4.2 million households. The company has been testing VoIP using the ADC Cuda 12000 and Packet Telephony Module as part of a vendor consortium led by Nortel Networks Inc. and plans to begin offering services commercially this quarter, says Callahan spokesman Chris McLaughlin.
"We're getting outstanding results in terms of performance reliability," he says.
What makes the ISH deployment so significant isn't just its scope, which, with the collapse of Videotron Ltd.'s cable VoIP rollout plans in Quebec, is by far the largest announced deployment of PacketCable anywhere.
"Callahan is the only cable operator in Europe that's rolling out real VoIP at this point," says Andy Mullan, vice chairman of the EuroPacket Cable Forum and a consultant to ADC. "Everybody in the world is sitting on the fence watching Callahan."
But nobody has been more aggressive about moving into VoIP than the strategists at Philadelphia-based Comcast Corp., whose senior vice president of strategic planning, Mark Coblitz, has been head of the CableLabs PacketCable initiative from its inception.
Comcast, like other U.S. multiple system operators, has been testing various approaches to VoIP and has concluded the best approach might be to offer the service on a second-line basis, and as a means for bringing special value-added services to the consumer, Coblitz said during a talk at a CableLabs meeting last year.
"The (first-line) business model is pretty tough," Coblitz acknowledged. "To scale to hundreds of thousands or millions of customers, you need to have some really extraordinary stuff going on in the back room."
But this might not be the last word in light of new technology entering the marketplace. Competing with ADC's tightly integrated CMTS/VoIP gateway system is what David Spear, president and CEO of Cedar Point Communications, refers to as a "whole new category of switching technology."
The Cable Media Switching System supplied by the Windham, N.H.-based startup offers a migration path to primary line VoIP for operators not ready to make the leap immediately, either by way of integration with legacy TDM-based cable voice systems or via an evolutionary path that starts with second-line services, Spear says.
"There has been too much complexity in the systems operators have been working with up to now," Spear says. "What we've done is combine all the distributed elements of the PacketCable platform into a single unit that can handle both VoIP and circuit-switched voice calls simultaneously on a single packet switch."
All the functions, including call control, media gateway and media gateway controller, signaling gateways and media and feature servers, are supported in a 19-inch rack-mounted unit capable of handling more than 100,000 voice lines, Spear adds.
Comcast is the first cable company to undertake a lab test of the Cedar Point technology, which the vendor hopes will be ready to ship for commercial deployments by the third quarter.
Meanwhile, cable operators should leverage their existing high-speed, DOCSIS-based data infrastructure to jump into enhanced IP communications services, suggests Ofer Shapiro, senior vice president of RADVISION Ltd. The RADVISION solution, based on the H.323 IP communications standard, doesn't require implementation of the PacketCable VoIP platform.
"We're working with the cable industry as it moves toward a videoconferencing capability within PacketCable," Shapiro says. "But we believe there's a big opportunity to use the broadband data system operators now have in place to generate new revenue from videoconferencing."
