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November 2006, Volume 9/ Number 11

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Cable Telephony �

Good Enough for the Enterprise?

By Richard �Zippy� Grigonis


Quality has always been a big factor when it comes to cable telephony. Indeed, cable MSOs (Multi-Service Operators) tested VoIP �to death� before they finally deployed it, carefully working out the whole environment, including the architecture, back office, price points and service set.

Cablecos were in no hurry, since in the late 1990s, their competitors, the telcos, were not exactly thrilled about selling IP voice, because it would undercut the profitability of their own circuit-switched operations. Besides, most telcos at the time were more infatuated with the problem of competing with cablecos in terms of video, of having to distribute standard and HDTV across suburbs either over ancient, existing copper wires or a new, expensive fiber-to-the-home (or to-the-neighborhood) infrastructure.

Cable companies realized that the opportunity was waiting for them and they continued to tinker and test until they were happy with the technology. (A few took an easier route by reselling somebody else�s VoIP service.) Initially, cablecos were so conservative that some became suspicious of VoIP itself, adopting, instead, TDM-based, constant bit rate (CBR) systems, such as those from Tellabs. In North America, Cox (News - Alert) had over a million lines of TDM-based voice, and then there was EastLink and AT&T Broadband, which eventually was acquired by Comcast. Ultimately, however, softswitches and CableLabs� PacketCable architecture and Line Control Signaling (LCS) scheme won the day, and pretty much all of today�s cable operators offer VoIP.

Not that cable operators like to call their voice services �VoIP� � each cableco uses a different name for Cable VoIP. We�ve seen �digital voice� and �cable phone.� Some just call it �local service� in an effort to make it psychologically reassuring and imbue it with the confident, serious ambiance of conventional circuit-switched phone service.

Whatever they call it, as the world adopts IMS (the IP Multimedia Subsystem (News - Alert)), along with triple and quad-play services, all cable companies and telcos will ultimately move to an all-IP framework.

But before that great day arrives, cable companies even now are venturing from their traditional residential market, and have begun offering VoIP service to small and medium-sized businesses (SMBs).

For example, Vid�otron, Quebec�s leading cable operator (the third largest in Canada) has been rolling out VoIP service to both residences and businesses. Knowing that the world will be saddled with an IP/PSTN hybrid network for a couple of decades, they needed end-to-end equipment that could handle both IP and PSTN communications flawlessly. So, when Vid�otron decided to expand telephony services to their 1.5 million customers, they chose Nortel (News - Alert) ( as their primary VoIP technology and professional services provider.

Nortel�s Director of Cable Marketing, Elaine Smiles, says, �Vid�otron will be using our Nortel Communication Server [CS] 2000-Compact softswitch, which is fully PacketCable qualified � an important criterion for cable operators. They�ll use it in a central location and will roll out services to the entire province of Quebec. They�ll also be using the Nuera BTX 4000 media gateway that�s bundled and sold through Nortel. Vid�otron will use both PacketCable and SIP protocols to create a comprehensive offering of residential and business services. Vid�otron�s VoIP service will leverage their existing Optical DWDM and SONET network, which is based on the Nortel Metro Ethernet Networks portfolio including the Optical Metro 5100 and Optical Metro 3500. These will provide IP voice transport and business services to more than 16 locations in the Quebec-Montreal-Toronto corridor.�

�Fairly often we find that cable operators don�t want to emphasize Voice over IP in the name of their voice services just because they want to differentiate their offerings from a Vonage (News - Alert) type of solution,� says Smiles. �What they�re deploying with the PacketCable standard architecture and with Nortel is a rigorous, carrier-grade quality of service [QoS], fixed-line service. The common residential subscriber isn�t going to jump up and exclaim, �Hey, this is PacketCable-compliant instead of regular VoIP!�. In fact, because the market often looks upon regular VoIP merely as a best-effort service, many cable operators choose to emphasize the �phone� aspect and de-emphasize the �VoIP� part. In the case of Vid�otron, they just call it �local service�.�

�Of course, a key factor in Vid�otron�s selection was that we could do the PacketCable residential deployment, but another was that we could help in their business services area, thanks to our softswitch,� says Smiles. �That�s a real differentiator for our softswitch in the cable space. Smaller vendors have created custom products specifically for cablecos with residential features. But an operator can leverage the same Nortel softswitch that can be used in both cable and telco markets. If you look at the keynote topics in most of the symposiums running this year, they�re all about how to get cable telephony into businesses. That was certainly important to Vid�otron. They needed a platform that could not only serve legacy business services, but one that could also pull in SIP and SIP multimedia services for both business and residential as they evolve toward IMS. After all, Vid�otron is an integrated communications company engaged in cable television, interactive multimedia development, Internet access services, residential telephone service, and wireless phone service.�

Good Enough for Business?

Minacom (News - Alert) ( builds service level test systems for telcos and cable MSOs, and ITSPs (Internet Telephony Service Providers). Minacom�s automated test systems help maintain the integrity and quality of large-scale multi-service deployments, including Voice, VoIP, IPTV (News - Alert), Caller ID, voicemail, conferencing, fax, dial-up modem, video conferencing, and IP services from Ping and DNS to audio and video RTP streaming.

Minacom�s Director of Marketing, Scott Sumner, says �We saw a VoIP survey by Brix that indicated that one in five VoIP calls was unacceptable. They were conducting tests using their portal. We realized that their study was actually based on analyzing peer-to-peer (PC-to-PC) Internet phone service, similar to what�s offered by Skype (News - Alert), Google Talk, MSN, and Yahoo Messenger, none of which have the quality or reliability of the kind of VoIP services offered by telcos and broadband VoIP providers.�

�We asked ourselves whether that trend is true with cable VoIP,� says Sumner, �which is a managed VoIP service, as opposed to something like Skype that goes from computer-to-computer, which is essentially what Brix was testing using a Java applet. We tested several different local cable VoIP providers here in Montreal. Our tests took 12 months and revealed the opposite � VoIP call quality had actually increased steadily over the past year, with an average Mean Opinion Score [MOS] of 4.2 � 5 is best � compared to 3.9 for the PSTN. It had just broken through the PSTN quality �barrier�. Amazingly, based on Brix� own MOS threshold of 3.6, only 1 out of 50 calls in North America were considered to be unacceptable � 1 in 10 worldwide � while more than 85% of VoIP calls exceeded average PSTN quality over the same period. Call studies by Minacom and other companies indicate that cable VoIP � or �managed enterprise VoIP� � is actually a serious challenger to wireline.�

�As amazing as those figures are,� says Sumner, �we believe that cable VoIP will continue to improve. There are a few things on the horizon, such as wideband codecs, for example, that really deliver high-fidelity voice calls. We�re starting to test wideband codecs now, and operators are considering deploying them for enterprise VoIP, especially for conference calls, in which case you�ll be able to do stereo conference calls.�

�In our market, we�re already seeing cable operators starting to offer enterprise VoIP,� says Sumner. �There are two ways they do this. First, for small businesses, they�re using a standard cable line along with new appliances made by Scientific Atlanta and Motorola (News - Alert) that have four or five MTAs [Multimedia Terminal Adapters] in a box, and it yields something like a 10-line phone system. They can gang them off of one cable line. It�s an interesting appliance � it�s like installing five residential phone services in a company. Second, the cablecos are moving into larger environments with full-fledged session border controllers, and things like an EdgeMark device, which will give priority to voice packets over data packets so as to achieve larger multi-line counts.�

�Cablecos have done well in the residential market,� says Sumner, �so they�re going up the food chain to the enterprise, and that will really start to hurt the telcos. SMBs are the immediate target � an EdgeMark device can handle up to about 50 lines. With these new managed services you can remotely connect to these boxes and check quality and various things from an EMS [Element Management System]. It�s an interesting offering. We�ve been working with other companies that are doing managed services for larger telcos, and that�s the approach they�re using as well.�

�We work with probably all of the leading U.S. providers and I would say that they all have a lot of room to grow,� says Sumner. �Comcast was a bit behind on the VoIP numbers but now they�re eating market share incredibly fast. A recent survey listed Cablevision as first, Time Warner (News - Alert) as second, and Comcast as third; Comcast had half the VoIP subscribers of Cablevision, but it grows at an incredible rate.�

Interestingly, Comcast (News - Alert) is going to initiate a �self-install� VoIP pilot project in Silicon Valley,� says Sumner. �You�ll be able to go to a store such as Wal-Mart and buy an MTA, take it home, and plug it in yourself. That�s something they�ve never done before; in the past, Comcast always sent a technician to your house to do an install. Other companies, such as Cox, don�t believe in self-installs. But I think most companies will be forced into this model, since the fastest way to deploy and capture market share is to have customers install their own device and service, which is predominantly what�s already happening in Europe. The big guys over there, such as Liberty Global, have completely self-installed subscriber bases. They don�t send technicians to your home unless there�s a problem. That trend will gradually come to North America. Even now you can go to a Circuit City store and buy a set-top box, take it home, plug it in, and it will work with many cable services out of the box. Also, people now install their own satellite dish systems, so these things aren�t as intimidating as they used to be.�

�To respond to this self-installation market, we at Minacom have created a new IVR [Interactive Voice Response] VoIP test system called �Zoey�, which you can call on your phone. Zoey walks you through a series of tests of your caller ID, echo, noise, MOS score speech quality, touchtone, fax transmission capabilities, and 50 QoS metrics to determine if your handset or installation is having a problem. It also works for companies like Vonage or companies that are offering a �pure Internet� telephone service. It�s basically a test probe, but there�s no technician at the end of the line. If there�s a problem, Zoey transfers the call to the service provider�s support team along with the test results to get the customer up and running. The test results are stored on one of our DirectQuality R7 servers and are accessible by operations staff, field technicians, billing systems, and so forth.�

Onward to IMS and FMC

No tour of cable telephony (or any kind of VoIP) would be complete without a sit-down with the IP behemoth, Cisco ( Cisco is a very large player in the cable voice market. Their immense portfolio ranges from equipment in the customer premise itself, through things like Linksys (News - Alert) devices, all the way up through the network infrastructure. Cisco�s CMTS (Cable Modem Termination System) is a Cisco uBR (Universal Broadband Router) that�s able to communicate with a DOCSIS (Data-Over-Cable Service Interface Specification)-compliant HFC (Hybrid Fiber Coaxial) Cable network via a Cisco MCxx cable modem card. Additionally, Cisco�s BTS 10200 is one of the leading softswitches in the cable voice market and is directly responsible for generating a great deal of revenue seen by service providers.

Jonathan Rosenberg, a Cisco Fellow in the Service Provider and Routing Technology Group at Cisco Systems (News - Alert), says, �To be frank, VoIP has been a resounding success in the cableco world. Many operators report excellent take rates. VoIP has a direct impact on the bottom line of these companies. It shows that the triple play model of voice, video and data services is compelling to customers.�

�Cisco is almost a top-down infrastructure provider in the cable telephony space,� says Rosenberg. �We cover almost all aspects of the network architecture, ranging from the access device itself to the CPE to the IP network from the access side, backbone, interconnect networks, interconnect networks, call control, and PSTN interconnection.�

�Most cable efforts are at least triple play,� says Rosenberg, �but the big looming issue in the industry is. . . what about quad play? What about that fourth, mobility aspect? Many cable operators want to get to mobility as another angle of that service, but it�s pretty much �up in the air� as to how exactly they�re going to get there. Much of it has to do with whether or not strong business relationships can be forged with cellular operators, or whether the cablecos will go their own way and build their own infrastructure, or lease it, or whatever. We�re still in the very early stages. Several MSOs, including Comcast and Time Warner, have announced a joint venture with Sprint (News - Alert), targeting the addition of that wireless component. Then there�s the MVNO [Mobile Virtual Network Operator] model, where the MSOs become virtual network operators, and �lease� a logical piece of the wireless network. Finally, people hear rumors about acquisitions all the time. I even hear stories about operators building out networks, whether it�s traditional cellular-to-WiMAX or WiFi (News - Alert) meshes or whatever.�

�None of these plans are cheap or easy,� says Rosenberg. �This isn�t like installing a little box in the network. It will take time to sort out.�

�Bridging services to wireless of course suggests IMS and FMC [Fixed/Mobile Convergence (News - Alert)],� says Rosenberg. �But nothing�s black or white. IMS is a whole huge suite of technologies, so cable operators will most likely work incrementally toward IMS, adding little bits and pieces of it as necessary to support whatever application or business problem happens to be sitting at your front door. IMS is a sort of target blueprint toward which an operator builds. But IMS by itself is not a business proposition � it�s an architecture. To do six-layer convergence will require some pieces of IMS supporting SIP line-side interfaces, for example, and supporting some application interfaces to support the anchoring server needed for an application.�

�We at Cisco are moving into the IP network from the access side to the backbone,� says Rosenberg, �encompassing interconnect networks, call control, PSTN interconnection, and so forth. We�re continually evolving out products. As operators devise new applications they want to deploy, we�ll be right there with them to support them and their billing infrastructure.� IT

Richard Grigonis is Executive Editor of TMC�s IP Communications Group.

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