Empty promises

Does voice over IP finally give cable operators a real weapon?

For the past several years, cable operators' promises to get into the residential telephony market have held about as much weight as Gerry Cooney threatening to get back in the boxing ring.

Even AT&T's entry into the cable market, which was largely predicated on the ability to bypass local exchange carriers (LECs) by delivering voice services directly to the consumer, has failed to make much of a dent in the market.

So while last month's Western Cable Show in Los Angeles turned out to be something of a coming out party for IP voice over cable, local telcos still can be forgiven for responding to cable operators' third (or fourth) attempt to get into the voice market with a big yawn.

This time around, though, market dynamics and changing technology point to the fact that LECs may finally be facing a competitor that is on equal ground. In some cases, cable operators will be even better equipped than the incumbents to offer next generation services, including bundled voice and data packages.

Part of the new threat comes from the changing economics of the local voice market. IP voice is having its impact on the long-distance market to be sure, and many anticipate the same economics to continue migrating to the local market.

Cable counter culture Given the significantly lower cost of deploying IP-based voice services compared with circuit-switched services, cable operators theoretically start with a leg up. And in fact, many cite the cost differential between IP- and circuit-switched service as one of the reasons they are experimenting with voice services.

"We have a lot of synergies between [our DOCSIS infrastructure and IP voice] and that ultimately we'll be able to deploy voice on a much better cost basis than a circuit switch," says John Pietri, senior vice president of engineering for Charter Communications, which last month announced its second IP voice trial.

It's the ability to use voice as just one part of an overall communications package that has vendors and operators most excited, though. Talk to virtually any vendor about IP voice service, and the conversation will quickly turn to an overall bundle of services - ironically something telcos have talked about for years, but have failed to deliver.

During a session on the technical issues involved in deploying voice over IP over cable networks at the Western Show, John Sharpe, Cisco Systems' director of engineering services, said cable operators must think of voice as just one of many services floating over a DOCSIS-based network.

Indeed, several operators considering voice-over-IP trials say part of the technology's appeal is the ability to provide multiple services while paying for only a single infrastructure.

"We approach the voice business from a different perspective than [a company] that wants to be a CLEC," says J.R. Anderson, former vice president of voice services at High Speed Access, a provider of Internet services for cable operators in small and medium-sized markets. The company signed a $100 million deal with Lucent Technologies to provide voice-over-IP equipment. "We view it as an additional service that can be bundled," Anderson says.

Among the myriad of services being contemplated, one of the most enticing is the ability to offer virtual lines, essentially allowing users to activate lines on a short-term basis.

"A lot of people are interested in second lines," says Joseph Morris, chief technology officer of Net2Phone's broadband division, which is considering putting its protocol into residential gateways. "Rather than going through the phone company, you can basically just buy this box and get a second line right away. Or say you have your kid home from college - you can set up a line for two weeks. The important thing is whatever we put into the home is easy for the user."

So close, yet so far Despite such pronouncements, a number of factors - particularly a dearth of quality of service (QOS) standards in the IP backbone network - is leaving the cable industry a long way away from truly challenging local telcos with anything resembling a competitive voice-over-IP service, according to most vendors and operators.

"It's not just voice," said Sharpe at the Western Show. "It's all about having a reliable data infrastructure also."

Cisco currently is providing equipment to Videotron, a cable operator in Quebec, Canada, that has the largest trial of voice over IP over cable in the world. In the U.S., Comcast was among the first to begin trials, though it has been followed by a number of other operators, including Charter.

Even Charter, which with its voice-over-IP announcement last month is considered at the forefront of voice over IP over cable, admits it's taking the service slow, rolling out a St. Louis trial to between 250 and 300 friendly customers early this year. "We're trying to simulate the service we'll roll out and being careful," says Mike Emmendorfer, corporate network engineer for Charter.

Being careful also means monitoring every portion of the cable plant, something that cable operators have not traditionally done. "[We're deploying voice over IP] to groups of nodes over two hub areas so that we can understand how the nodes and hubs interact," Pietri says.

Even in Quebec, where Videotron has 12,000 customers up and running on primary line service, progress currently is up in the air after the company decided to slow investment and re-evaluate its plans in light of a takeover bid by Media Acquisition, Quebecor and Capital Communications CDPQ.

At its most basic level, cable operators must deal with customers accustomed to high-availability services when it comes to voice.

"The telephony application is the most demanding because the user expectation is so high," Sharpe said. "This isn't something that you're going to do in a couple of weeks."

In fact, according to many vendors, cable operators won't be offering large scale IP-based telephony services until QOS capabilities are in place, which could take years.

"Today our view is that the only way you can deploy lifeline voice over cable is with Class 5 switches," says Kenneth Craft, director of business development for Tellabs' broadband media group. "What we're seeing is that a resurgence in the call server IP model is out there in time. 2001 still seems to be a year of trialing the call server model - not commercial rollouts, but market trials."

Much of the expanded timetable comes from the flux in QOS standards. Ironically, with the lack of experience cable operators have in delivering voice services, the QOS question actually resides outside their traditional boundaries - in the backbone. In the access portion of the network, CableLabs' DOCSIS 1.1 - and to a lesser extent PacketCable - are expected to include most of the QOS elements needed to provide IP-based voice services. However, according to most vendors, neither standard is ready for prime time.

"In terms of QOS, DOCSIS 1.1 is not far along enough to do certification," says Wade Carter, director of R&D for Arris, which is providing equipment for Charter's St. Louis test and also has conducted a trial with Adelphia. "We've started implementing DOCSIS 1.1 QOS mechanisms."

Within DOCSIS, CableLabs has marked a service identifier (SID) within the media access control (MAC) layer, allowing cable operators to tab specific packets such as voice, thus giving them priority, says Charter's Emmendorfer. "If you look at the SIDs that are associated with CableLabs, there are some that are best effort and then there are others that look something like DiffServ. DOCSIS has solved the QOS over the HFC access piece. We basically nail up a circuit over the HFC for the voice service. QOS over the backbone is more problematic."

Currently, most of the industry is looking to multiprotocol label switching (MPLS) to provide QOS within the backbone, Emmendorfer says. However, the technology isn't ready just yet, and a number of options already exist, including integrated services (IntServe), DiffServ and resource reservation protocol (RSVP).

"The original QOS was best effort, and while that may work for data services, it won't work with voice," says John Chapman, distinguished engineer for Cisco. IntServe, which is available now, is too difficult to implement, he added. However, IntServe could be used as an element in the final solution.

Many believe DiffServ will form the basis of QOS in the backbone. "DiffServ is an excellent first deployment strategy," Chapman says. "It's ready today and it's being deployed."

RSVP, the signaling protocol for IntServe, also is being combined with DiffServ to create what Chapman calls the best of both worlds. Aggregate RSVP will make a single reservation on behalf of a large number of individual flows across a DiffServ network. MPLS, which is being pushed heavily by Cisco, brings QOS to the next level, Chapman adds. "MPLS is really a tunneling technology. It doesn't really replace DiffServ; it complements it," he says.

However, MPLS isn't ready for large-scale deployment, according to most vendors. In lieu of that, cable operators initially will likely hand off voice traffic to a dedicated managed network designed for voice. Net2Phone is striking deals with a number of vendors - including Motorola's broadband group and Broadcom - to integrate its protocol into cable modems. Of course,the peripheral result leads to more traffic on Net2Phone's network.

"The way people are doing [voice over IP over cable] now is taking the call and putting it in a Class 5 switch," Morris says. "We want to go to the Net2Phone network. In all these cable networks, you really need DOCSIS 1.1 to get the QOS in there."

In early voice over IP over cable trials, calls that need to be handed off to another carrier for completion are passing through gateways before hitting the public network. In the Charter trials, the company is using softswitches from Nortel Networks and Telcordia.

Blocking and tackling Beyond the technology, cable operators have other hurdles before being able to deploy voice-over-IP services on a wide scale. For one, the physical form factor still is unsettled. In some cases, IP voice will be delivered through an RJ-11 jack off the back of a cable modem or set-top box. In other deployments, residential gateways will be used inside the home or in an environmentally hardened case on the outside.

In most cases, gateways outside the home are preferred because of the lower operational cost. "We believe that an outside mounted unit is best because if the unit fails, you can just drive out and replace it," Arris' Carter says.

Some vendors also are pushing the idea of session initiation protocol phones that are defined by remote software, possibly leading to even fewer truck rolls.

More mundane issues that come with transforming a company from a video service provider to a voice/data carrier also need to be addressed.

"One of the biggest challenges is addressing all of the operational issues," says Mary Turney, vice president of next generation solutions for Telcordia. "If we're asked just to ship a call agent, we could have the customer up and running in a month. The biggest challenge is within the companies. It really ends up being something that seems like it's very boring, but it's very difficult to do things like provide bills."

Indeed, even routine matters such as providing power can become complicated when implemented by operators that have never been concerned about such issues. Like telcos deploying fiber to the home, cable operators must choose between local and network powering schemes. In most cases, Carter says, operators are moving to network powering that place power nodes in parallel with existing hubs.

"I think that the customers that are doing the locally powered systems with battery backup are now understanding better the logistical problems and are moving toward the network powering scheme," he says.

At the highest level, though, cable operators must begin to think like telcos, something that hasn't happened just yet, he adds.

"The MSOs have had to take on a telco-type mentality in terms of QOS in all of their operations. That is a very big mindset shift."

IntServe - Integrated Services is primarily associated with RSVP, but often describes the overall QOS efforts across an IP-based network

DiffServ - Differentiated Services marks packets with specific tags that prioritize them in the IP traffic flow

RSVP - Resource reservation protocol is the signaling protocol for IntServe. RSVP negotiates end-to-end QOS across an IP network. In a PacketCable-based network, RSVP can negotiate QOS on the cable access network

MPLS - Multiprotocol label switching lets edge routers apply simple labels to packets (frames). Switching entities in the network's core then perform table lookups based on these labels to determine where data should be forwarded