While some MSOs opted to take the early plunge
on circuit-switched telephony, several others are driving
down the VoIP path as the technology continues to mature

Mr. Watson, come here. I want to see you."

Those words, as telephony lore has it, were spoken by Alexander Graham Bell in 1876 to his assistant Thomas A. Watson after Bell accidentally spilled battery acid on his knickers. As everyone knows, the significance is not that Bell could be a clumsy oaf, but that the words he uttered were heard by Watson over what is hailed as the first telephony transmitter.

From there, of course, Bell went on to found the Bell Telephone Company in 1877. But enough with the history lessons for today.

The cable industry today is busy writing its own telephone history, but, for the most part, with pens dipped in traditional constant-bit-rate (CBR) technology. Well into development now is Voice-over-Internet protocol, the Mont Blanc of the telephony pens as it promises a slew of features and applications that can't be offered over legacy CBR platforms.

Although they wouldn't represent the same revolutionary step as Bell's experience, the following words could be music to MSO ears by next year: "Mr. Cable Operator, come here. I want Voice-over-IP."

At the same time, AT&T Broadband, Cox Communications and Insight Communications have enjoyed some success with their constant-bit-rate telephony services, while several others that didn't take the CBR bait initially are just about done playing the waiting game with VoIP.

Steve Craddock
Steve Craddock
While the business case for VoIP still needs plenty of work [more on this on p. 12], the technology behind it has strengthened and solidified over the last 12 months or so, cable execs say. "[VoIP] technology, a year ago, was pretty spotty," says Steve Craddock, Comcast Cable Communications Inc.'s senior vice president of new media development. "Right now, it works fairly well."

Though issues tied to VoIP OSS and provisioning systems still need ironing, that hasn't stopped cable operators from testing it in the lab or in the field.

Charter, for example, plans to launch a VoIP marketing trial in Stevens Point, Wis., which follows technical tests there and in St. Louis. Looking ahead, the MSO plans to expand its IP telephony rollouts by next year and into 2004. Charter also offers CBR in St. Louis, Mo., albeit in a roundabout way. The company started offering the service there after inheriting the system via a swap with AT&T Broadband.

While not every operator is on the same page with its VoIP plans, what follows is a rundown of how far along they are today, and how they are formulating plans for the not-too-distant future.


Expect AT&T Broadband, at least until its merger with Comcast goes through, to continue down the primary-line, CBR path.

And why not? Although offering circuit-switched telephony via cable has been likened to throwing money down a black hole, the MSO has managed to sign up more than 1 million CBR subscribers and expects to turn a profit on the service nine months ahead of schedule.

Still, AT&T Broadband is planning to deploy the underpinnings of PacketCable–DOCSIS 1.1–rather quickly, and expects 1.1 to be, according to Chief Technical Officer David Fellows, "all over the place" by the end of 2003. Tiered data services will be the big push behind DOCSIS 1.1 for the MSO, but VoIP might not be that far behind.

Though the MSO remains extremely fond of primary line voice services, AT&T Broadband might consider second-line VoIP services for alternative applications such as Internet chat, Fellows says.

AT&T Broadband has tested a hybrid VoIP service in Boulder, Colo., and last year issued a VoIP RFI. The MSO is paring down that list today, says company spokeswoman Sarah Eder, who declined to say when AT&T Broadband plans to announce who will make the final cut on the RFI.

RFI or no, the MSO won't take the VoIP plunge "until the technology is at parity or better than what we have today," Eder says.


Comcast, which is in the process of acquiring AT&T Broadband, has pure-IP squarely in its sights. Since the beginning, Comcast has argued that going the circuit-switched route just doesn't make economic sense for the MSO.

Like Time Warner Cable, Comcast was one of the early movers on VoIP technology via a proof-of-concept trial in Union, N.J. that coupled Motorola Broadband modems with Lucent Technologies' now-defunct PathStar system. "We learned more about what we didn't want to do than what we did want to do, which is the nature of trials," Craddock says.

Closer to what Comcast does want to do happened in the Detroit, Mich. area–a former MediaOne CBR market Comcast acquired in a swap with AT&T Broadband. There, Comcast complemented its CBR service with a VoIP trial using Arris' C4 CMTS, Motorola's cable modems and TollBridge's GR-303 interfaces that link with the existing Class 5 switch. Comcast kicked off that trial in October 2001 and wrapped it up last month.

Comcast might use VoIP to expand service in areas where CBR is lightly penetrated. That's because "the relative economics between the two [approaches] are worth a look," Craddock says. Further down the road, Comcast plans to deploy VoIP services based on the full PacketCable infrastructure. In the meantime, Comcast and Craddock are testing that out in the lab.

Comcast issued a VoIP RFI last February, just ahead of AT&T Broadband's. Comcast has since narrowed its lab testing field to about eight softswitches, and has been baking off DOCSIS 1.1 CMTSs for several months, Craddock says. "If you're going to provide VoIP, it has to be over a DOCSIS 1.1 network and it has to be over a carrier-class network," he adds. "That means it's not okay for you to have to reboot the modem every five minutes. It's also not okay for a technician in the headend to reboot CMTSs."

Following the softswitch bake-off, Craddock hopes to emerge with two or three softswitch vendors that are committed to PacketCable "and really understand the cable infrastructure to help us with providing top-class VoIP service."

Until a fully PacketCable-compliant network is achievable, Comcast will continue to look at VoIP in the access network like it did in Detroit. "I'm traditionally against that as a strategy...if it means I have to go off and buy a switch," Craddock says.

If all goes well with the current softswitch lab tests, Comcast might consider a true market trial for the technology later this year, he adds.


Although Cox has done well with its CBR telephony business (the company ended 2001 with nearly 500,000 Cox Digital Telephone customers), there are a few items on its agenda for this year designed to enhance the service.

Chris Bowick
"We want to add some advanced call functionality this year on the circuit-switched side," says Cox Senior Vice President of Engineering and Chief Technology Officer Chris Bowick, referring to elements such as "talking" call waiting and caller ID.

Despite Cox's success with CBR, the MSO isn't "keeping our heads in the sand relative to voice-over-IP," Bowick adds. "We'll be doing some [VoIP] trialing this year."

Presently, Cox is conducting such a technical trial in Oklahoma City, Okla., where the MSO already offers circuit-switched services. Instead of pure-IP, the trial is employing IP in the access network via a GR-303 gateway.

Referring to the Oklahoma City trial as a "living laboratory," Bowick says Cox plans to rotate a variety of vendors through the pilot program, and to look at VoIP functionality and features that go beyond what the MSO can offer via its CBR platform.

In addition to providing a VoIP infrastructure on the line side of the switch, Cox could use the technology to expand the geographic reach of its CBR product. With a GR-303 gateway in front of the switch, Bowick notes, Cox can extend additional line counts in that switch and improve efficiencies in such a way as to offer voice services to areas not being served today by the MSO's CBR network.

Although Cox's current VoIP trial is for primary-line voice service, the MSO also plans to explore market trials for "alternative-line" services via DOCSIS 1.1-capable multimedia terminal adapters and cable modem termination systems.

Still, trials, both from a technical and business standpoint, will determine VoIP's final fate for Cox's future plans.

Cox, before the end of the year, hopes to test an overlay softswitch system–both in markets where Cox does and doesn't offer CBR today, Bowick says. Still, don't expect Cox to migrate its CBR customers to VoIP unless the value for customers is apparent and the return-on-investment meets up with the bottom line.

Cox's plans to conduct a softswitch trial this year will "give us a better feel for whether or not voice-over-IP can be real from a commercial perspective in 2003," Bowick says.


Insight Communications Co., like Cox and AT&T Broadband, has deployed CBR technology initially to offer primary-line voice services. Insight, through a relationship with AT&T, has CBR voice in two markets (Louisville, Ky. and Evansville, Ind.), with plans to extend the service to Anderson, Ind., Columbus, Ohio and Lexington, Ky. Insight ended the fourth quarter with about 6,000 telephone subscribers.

Charlie Dietz
Charlie Dietz
Though Insight is starting to take a look at VoIP, it's still too early for the MSO to begin testing out or rolling out the service, says Charlie Dietz, Insight's chief technology officer. "We need to better define and rollout [DOCSIS] 1.1 and PacketCable," he says, noting that Insight looked at the technology about 18 months ago, but determined that it wasn't quite ready. That prompted Insight to explore CBR, which culminated in its relationship with AT&T.

"That said, I'd love to get IP and have that efficiency [so that] I'm not carving bandwidth out for every individual application, and in some cases, having it sit there unused when I have a need for it for a different application," Dietz says. "So we, like the rest of the industry, will definitely be following [VoIP] closely and, when the time is right, we will be shifting toward it."

In the meantime, Insight is also discussing the concept of VoIP in the access network via a GR-303 interface to complement its CBR plans. "The next new market we go into, we'll definitely look and see if IP is ready at that point, and then if it is, go with it," Dietz says.


Though Mediacom Communications' most recent attention has centered on the Excite@Home conversion and early deployments of video-on-demand, the growing maturity of VoIP equipment is starting to gather interest at the MSO.

"It looks to us like the hardware development has come along with the MTAs and the modems...that it makes sense for us to move ahead," says Joe Van Loan, Mediacom's senior vice president of technology.

But not too far. Instead of jumping ahead with nascent softswitch technology, Mediacom is looking to partner with another company and perhaps leverage Class 5 switches and employ a GR-303 interface in the access network.

Van Loan says Mediacom is starting to meet with prospective suppliers and partners to bring together the technical elements for a future GR-303 trial, possibly for a second-line service. But the primary-line vs. second-line service question hasn't been answered from Mediacom's standpoint, he says. Then, as other equipment based on PacketCable begins to solidify, Mediacom would gravitate to a pure-IP service, Van Loan says.

In the meantime, Mediacom will offer trials in order to "give us [telephone] experience, brand identity...and customer loyalty," he adds.


Attending a different school of thought is Time Warner Cable, which is offering "second-line" VoIP services to existing Road Runner customers in Portland, Maine and Rochester, N.Y. The MSO is also testing VoIP in Tampa. "LineRunner," as it's called, goes for $9.95 per month, or a bit more when features such as caller ID and voice messaging are factored in.

Time Warner Cable injects quality-of-service (QoS) on DOCSIS 1.0 gear via a proprietary piece of software made by Cisco Systems Inc. Though not part of any CableLabs initiative, cable insiders commonly refer to the modification as DOCSIS 1.0-"plus"–the "plus" being the part that handles limited QoS inside Cisco CMTSs.

Paul Gemme
Though this piecemeal approach is up and running in a couple of Time Warner Cable markets, DOCSIS 1.1 "is essential to launch voice-over-IP in any significant fashion," says Paul Gemme, Time Warner Cable's senior vice president of network engineering. "1.1 is going to give us true quality of service."

Time Warner Cable is evaluating DOCSIS 1.1 gear today, although the company still needs to conduct regression testing on the software to make sure it's compatible with equipment the MSO has installed in the field, Gemme says.

With a pending progression to DOCSIS 1.1, Time Warner Cable hopes to do the same with VoIP service expansions sometime this year, but has yet to say exactly when and where that might happen. "Once you know a service is good, of course, you're going to deploy it, and you're going to deploy it widespread," Gemme says.

Time Warner Cable plans to continue with its alternative-line approach. That's because backup powering remains expensive, especially for ubiquitous coverage, Gemme says.

Beyond that, Time Warner Cable is also looking at the potential for a "magic phone" that can handle home use, but is also capable of cell calls. "It's a possibility," Gemme notes. "And we all know that cell phones are pretty reliable at this point, and as a secondary form of reaching 911, it's not bad."

On the point of secondary-line, Gemme reiterates that Time Warner Cable's offering will have 911 capability. "The problem is that if the power is off in your home, then you may not" be able to dial 911. But, with a magic phone, it would have backup power to make calls, he contends.

That combination would be better than today's portable home phones, which rely on AC power to stay lit, Gemme says. "The phone companies have not been forthcoming in telling their customers this," Gemme says. "So, there are a lot of people...[who] are sitting there fat, dumb and happy, and they don't have 911 service if their power goes out."

To combat the powering issue, Time Warner Cable hopes prices, both for the base service as well as cheaper long distance rates, will draw consumers to the LineRunner service.


Vendors, finally in-sync with cable operators' VoIP aspirations, are eagerly anticipating the day that MSOs begin rollouts in earnest.

"After some delays, we think [VoIP] is finally ready to happen," says Bruce Swail, vice president and general manager of Motorola Broadband's telephony systems group, which has participated in about 20 VoIP trials worldwide.

IP Unity, a company that makes media servers, application servers and unified messaging platforms specifically for cable operators, is seeing traction as well. "We'll see some aggressive players in the third quarter, but most are for the fourth quarter," says Brett Azuma, IP Unity's senior vice president of marketing. Cable operators "have been giving us rollout plans, customers and homes passed estimates," he says.

Cable modem maker Toshiba America is also seeing some momentum for its DOCSIS 1.1-certified models, including its PCX3000 telephony modem, says Christopher Boring, marketing communications manager for Toshiba's network products division.

"Generally speaking, most operators are taking a serious look at [VoIP]," adds Arris Vice President of Broadband Marketing Stan Brovont. "Many are doing at least some degree of product selection in anticipation of deployments either late this year or early next year." ID


Telephony snapshot: Though constant-bit-rate (CBR) telephony rules most cable voice deployments, smaller VoIP technical and marketing trials are beginning to sneak in. Here's a smattering of examples:

Adelphia Communications

Buffalo, N.Y.–VoIP trial

Armstrong Cable Services

Conducting VoIP trials in systems based in Ohio, Pennsylvania,

West Virginia and Maryland.

AT&T Broadband

Atlanta, Ga.–CBR commercially deployed

Boston, Mass.–CBR commercially deployed

Chicago, Ill. –commercially deployed CBR

Dallas, Texas–commercially deployed CBR

Denver, Colo.–commercially deployed CBR (also tested VoIP in Boulder)

Hartford, Conn.–commercially deployed CBR

Jacksonville/Pompano, Fla.–commercially deployed CBR

Los Angeles, Calif.–commercially deployed CBR

Pittsburgh, Pa.–commercially deployed CBR

Portland, Maine –commercially deployed CBR

Richmond, Va.–commercially deployed CBR

Salt Lake City, Utah–commercially deployed CBR

St. Paul/Minneapolis, Minn.–commercially deployed CBR

Bay Area (San Francisco), Calif.–commercially deployed CBR

Seattle, Wash.–commercially deployed CBR

Charter Communications

St. Louis, Mo.–commercial CBR and VoIP trial

Stevens Point, Wis.–VoIP trial


Detroit, Mich.–CBR service, VoIP trial wrapped up in April '02

Union, N.J.–early VoIP trial, shut down

Cox Communications

Orange County, Calif.–commercially deployed CBR

Omaha, Neb.–commercially deployed CBR

Hampton Roads, Va.–commercially deployed CBR

New England–commercially deployed CBR

New Orleans, La.–commercially deployed CBR

Oklahoma City, Okla.–commercially deployed CBR, plus

VoIP technical trial

Phoenix, Ariz.–commercially deployed CBR

San Diego, Calif.–commercially deployed CBR

Tucson, Ariz.–commercially deployed CBR

Insight Communications

Anderson, Ind.–planned 2002 CBR launch

Columbus, Ohio–commercial CBR launch is imminent

Evansville, Ind.–commercially deployed CBR

Lexington, Ky.–planned 2002 CBR launch

Louisville, Ky.–commercially deployed CBR

Time Warner Cable

Portland, Maine–LineRunner VoIP trial

Rochester, N.Y.–LineRunner VoIP trial

Tampa, Fla.–VoIP trial