Bulk and Sensitive Apps Call for Packet Inspection

Decisions on how MSOs will equip the metro and long-haul spans of their networks are turning on questions of efficiency and carrier-class capabilities. Efficiency appears to be a big part of Cox Communications’ decision to award a multi-year contract to OpVista for its MetroVista dense wavelength division multiplexing (DWDM) optical transport system. Cox is especially pleased with the gear’s ability to handle the physical tendency of signals to smear, or disperse, over long stretches of fiber. "We have networks that span over 180 km that OpVista’s longer reach allowed us to span without the use of dispersion compensation modules," says Cox Engineering Manager for Transport Systems Dan Estes. OpVista says its ultra DWDM technology enables it to reach up to 1,000 km without dispersion management. Dense and flexible Packing in those lambdas is something else that OpVista does well. Once aimed exclusively at telcos, DWDM is now a key enabler of cable’s effort both to converge and expand its services. The efficiency gains generally are associated with the C Band, or with wavelengths surrounding the 1,550 nm mark. "OpVista uses 50 nm spacing, providing for 80 individual wavelengths within the C band," notes Estes. "On each wavelength, they have four unique sub-carriers for a total of 320 individual circuits each capable of 2.5 Gbps throughout." Thirty-two wavelengths in this band may have seemed dense enough a few years ago, but little stands still in the realm of optics or in the demand for bandwidth. "Cox has exhausted that capacity in several markets with our CBS business customers, video-on-demand (VOD), voice circuits, and high-speed Internet capacity," Estes says. OpVista also makes use of reconfigurable optical add/drop multiplexing (ROADM) technology, a category that was hyped several years ago, but whose time now appears to have arrived. In this case it enables a virtual switching ring (VSR) architecture that seems ideally suited to the provision of commercial services, and a generation beyond what the competition can offer. VSR’s node-to-node provisioning makes it "infinitely faster than the telecoms," says OpVista president Ron Foster. "It’s as easy as clicking a mouse and giving (the customer) more bandwidth." Carrier-class In another development indicating that cable’s transport infrastructure is leapfrogging beyond status quo data and telephony networks, Ciena at once unveiled a carrier-grade switch and confirmed that Adelphia and Armstrong Cable are using it. Adelphia is not only using the CN 4360 Ethernet Services Provisioning Switch, but also is expanding the Ciena (formerly Internet Photonics) relationship that has enabled it to converge the Los Angeles networks and reduce the number of routers therein required. "Now we’re replicating that success in our systems," Harold Willison, Adelphia director of high-speed data transport, design and engineering, said in a statement. Specifically, the expansion concerns Cleveland; Colorado Springs, Colo.; Waterbury, Conn.; and West Palm Beach, Fla. And for the CN 4360, Ciena Director of Cable Product Marketing Mitch Auster says it is the first carrier-grade Ethernet platform that is specifically designed for the telco and cable triple play, thus taking direct aim at the incumbent, the 7609 Router from Cisco Systems. Among the CN 4360’s advantages, according to Auster, are a constant (deterministic) level of packet loss probability, as opposed to one that rises exponentially as the line/switch utilization (capacity) approaches its maximum limit. Ciena says the same performance metrics apply as capacity is plotted against latency, a crucial parameter for quality of service (QoS). Under the hood, Ciena says that what enables these improvements in performance is a switching fabric that eliminates head-of-line blocking, in part through a cell-based architecture that makes it easier for high-priority traffic to negotiate ingress and egress queues. Ciena is not alone in hurling carrier-class weapons at Cisco. Sterling Perrin, senior research analyst at IDC, says Juniper has followed the same approach. "Cisco was selling enterprise equipment into a carrier market," he says. "Juniper came out with a carrier-product from Day 1." —Jonathan Tombes As broadband networks mature, cable operators—as well as their telephone industry competitors—are taking aim at specialized audiences. This desire, and the onslaught of peer-to-peer (P2P) applications, is driving a key development in cable infrastructure. Several companies—Sandvine, Packeteer, Ellacoya Networks, Allot and Cisco Systems (through its acquisition of P-Cube)—are selling technology that can dynamically provision traffic based on what that traffic needs—and what the subscriber is willing to pay. These companies’ products perform deep inspection of Internet protocol (IP) packets, identify what they are and provision them accordingly. Initially, the gear was a reaction to operators’ desire to recognize and segregate the P2P traffic that was hammering their networks. Once that defensive measure is taken, however, the technology lets operators go onto the offensive, since it is based on a mechanism that identifies with great precision and speed precisely what is traversing the network at a particular point in time. There are two classes of traffic that need special handling. There are streams of great volume (such as P2P or movie downloads such as those offered by Movielink) and smaller streams that are sensitive to latency and/or jitter (such as voice over Internet protocol—VoIP—and games). In either case, the ability to meet customer needs can be a sales goldmine. "That’s where you get into allowing service providers to set up a service that’s specific to what the subscriber is trying to do," says Karl Toompuu, the director of product development for Bridgewater Systems. "Today’s gold, silver and bronze services really relate to how much bandwidth [is provided] …. Now they can look at things such as offering gaming services, where latency is a concern." Bridgewater’s software ensures that all the hardware and software the network "touches" are in sync with the type of configurations made by the policy server. Lindsay Schroth, a senior analyst with the Yankee Group, says that the industry is very interested in these tools. She says that this technical infrastructure will enable operators to offer higher quality VoIP and, in the future, gain revenue from high margin, but sensitive, services. This flexibility will be incorporated into overall marketing initiatives. Thus, for instance, a portal may offer super-fast downloads of movies for an extra per-month fee or offer games on a separate—and higher priced-tier. These developments dovetail with the PacketCable Multimedia (PCMM) specification from CableLabs. There is an element in the standard called an application manager. The job description of the application manager is the same as the proprietary gear being released by the vendors. "Packet Cable Multimedia … allows devices like ours to be the application manager, to identify traffic and signal the policy server," says Dave Caputo, Sandvine’s CEO and president. The Halo effect Something of an inflection point may have been reached last year when the Microsoft Xbox’s Halo 2 broadband video game went live. Caputo says that traffic on networks the company monitors increased by 500 percent when the game launched. It’s important to note that the challenge of Halo 2 is fundamentally different from that of P2P. Games don’t involve a lot of data, though what there is must get to its destination without delay. Such traffic, Caputo says, is being delivered to a finicky audience. "Those subscribers only value their Internet service provider (ISP) based on the QoS (quality of service) they are getting." It is clear that the five companies are honing in on an important network flashpoint. "Nobody really dominates," says Toompuu, who adds that Cisco’s integration of P-Cube technology is being closely watched. "In the end, the deep-packet companies have a very good opportunity in the coming year." —Carl Weinschenk