Voice over Internet protocol (VoIP) technologies have gone way, way beyond brouhaha and hype. VoIP gear on the show floor and real-world IP telephony experience discussed in the sessions made IP voice the most important underlying theme of this year’s National Show in New Orleans. In the opening general session, Time Warner CEO Dick Parsons said that the operator will have IP voice available in all of its systems by the end of the year. And, half of Comcast’s systems will be ready to roll IP telephony this year, and the rest should follow in ’05, noted Comcast CEO Brian Roberts. Of course, deploying VoIP technology across those kinds of footprints won’t come without some engineering angst. Hoping to make it a bit easier, technical experts shared their IP voice rollout experience at a breakfast panel sponsored by Nortel Networks and Communications Technology. Panelists stressed that cable operators need to differentiate themselves from the telephony competition by offering more options rather than getting into a price war. Additionally the stability of the network is key when using VoIP. The plant has to be "flawless" or you’ll have problems with IP voice services, Bill Dame, Cox’s director of network switch engineering said. And you need to ensure you have that clean plant from the get-go or you’ll risk "poisoning the well early on," Cameron Gough, vice president of advanced voice at Comcast warned. Yield management: packet planning If you can’t measure it, you can’t manage it—an adage that applies to cable networks no less than human performance. In a panel that discussed yield management, Bob Cruickshank, co-founder and vice president of Stargus, advocated nonintrusive (vs. intrusive) element (vs. packet) polling as the best way to measure the consumer’s consumption of network resources. Network optimization, especially desirable on the VoIP front, then entails automatic setting of appropriate configuration parameters for each CMTS-RF interface. To find the optimal mix between service level agreements (SLAs) and network capacity, Komandur Krishnan, senior research scientist at Telcordia Technologies, recommended a combination of monitoring and planning. This combination must be specifically oriented toward the demands of data and voice services. Krishnan said Telcordia uses a model known as Fractional Brownian Motion (a Gaussian model with stationary increments) that "takes explicit account of QoS requests." These algorithms, for example, could enable operators to defer capital expenses by predicting the increased benefits yielded by multiplexing at higher loads. Nielson data is another input useful for network planners venturing into the switched broadcast arena, said CableLabs Senior Technologist Joseph Weber. Given that 75 to 80 percent of viewership is tied up in the top 30 channels, the benefits of switched video are impressive—at least 36 percent and potentially more than 60 percent for a service group size of 500 digital subscribers. Just how to ship those video assets across cable’s metro and secondary hub networks remains a matter of debate. "What’s really needed is a third-generation (3G) SONET," said Dale Shpak, adjunct professor of electrical and computer engineering at University of Victoria. Overlay techniques for digital video and local data aggregation might be preferable, if they didn’t increase network complexity, Shpak said. What 3G SONET brings to the table is compatibility with existing infrastructure, plus capabilities such as frame switching, which provides for dynamic provisioning, multicast distribution, statistical multiplexing and tiers of QoS support. Standards-based protocols Mentioned before in reference to a switched broadcast model, Nielson viewing data also is crucial for the cable industry’s advertising business. The ongoing digital evolution, moreover, is changing the traditional channel-based, TV research paradigm. Thus the arrival of Nielson’s universal metering initiative (UMI) technology, explained Nielson Media Research CTO Robert Luff in a panel on standards-based protocols. Using a new family of Nielson’s audio and video encoders, UMI handles both digital and legacy automated measurement of lineup (AMOL) codes, thus ensuring coverage until the industry adopts and uses a new all-digital metadata standard. Other standards are here and now, if long-awaited. Consider the Open Cable Application Platform (OCAP). Four years after launching the OpenCable initiative, CableLabs released the OCAP 1.0 specification in December 2001. Fourteen months later, the SCTE Engineering Committee approved this spec as a standard (the SCTE’s 100th). Then CableLabs submitted a revised spec, which the SCTE approved in April 2004. The 388-page OCAP 1.0 document is being vetted further under the American National Standards Institute (ANSI) public review. Thereafter, it will be know officially as ANSI/SCTE 90-1 2004. The industry sounds more than ready for the set-top interactivity OCAP promises. "All of the things that we’ve been talking about for the last 15 years are really happening," Eric Miller, CTO of Vidiom Systems, said. "Not just in a demo room or a trial, but really nationwide-type services." The return on investments in transmissions systems, set-top boxes and software, along with the corresponding OpenCable standards (including OCAP) should begin appearing soon. "OCAP is about to change the face of the U.S. cable business," Miller predicted. Yet the tradeoffs between software limitations and desired applications will remain, Stephen Johnson, user interface designer for Coach Media, warned. The key is asking the right questions before application development begins, he said. PacketCable was the subject of two additional papers. Gerry White, chief technologist for Motorola’s network infrastructure solutions group, described how PacketCable Multimedia expands upon PacketCable 1.x to support enhanced IP multimedia services, in part by using application managers and policy servers to act as proxies for clients requesting QoS levels from the CMTS. Another paper written by a team of Lucent engineers explained how the ITU-T’s X.805 standard can be applied to the PacketCable security specification "to provide optimal availability and security for voice over cable networks." Digital encoding demystified If you find advanced video codecs befuddling, just keep a few things in mind. First, it’s been ten years since MPEG-2 was issued. Coding has improved in the interim, as Tandberg Television’s director of technology Matthew Goldman reminded those attending a digital encoding panel at NCTA. No technology stands still, and so something like MPEG-4 Part 10 or Windows Media 9 or Real Networks Real 10 Platform was bound to arrive. Second, "coexistence" with the new technologies is an option, explained CableLabs digital video guru Dr. Yasser Syed. (How so? For one, the transport and codex components of MPEG-2 are separable.) Finally, set-top vendors expect advanced encoding—as well as denser storage—to improve the efficiency of home networks running off advanced digital set-tops. That was one of the points that Scientific-Atlanta President Jim McDonald made in a press conference explaining S-A’s bet on a distributed storage future. Absent such advanced codecs in the home, operators will pay a higher network cost shuttling HD and other digital video assets to multiple boxes. From the emerging trends department: Cisco Systems and Comcast are thinking alike. Specifically, two great minds from these companies said on a NCTA panel that the software managing the network needs to be separated from the underlying elements, as well as the encrypted sessions themselves. "One of the most important things is to break out the session resource manager," said Bruce Thompson, technical leader at Cisco’s relatively new video networking business unit. To what end? "Innovation on VOD pump, and multiple edge server vendors," said Weidong Mao, Comcast’s senior director of advanced technology. No objection on that point from Cliff Mercer, director of technology for Kasenna, an advocate of open, off-the-shelf hardware. Advertising was another item that the panel flagged. "A significant amount of revenue is at risk," said nCUBE SVP Jay Schiller. "Now is the time to pull together." Among the tasks on his agenda: better ways to segment inventory, estimate break lengths, profile databases and report results. Laura Hamilton is editorial director and Jonathan Tombes is executive editor at Communications Technology. Reach them at [email protected] and [email protected].