Vendors Offer Bandwidth-Management Plans

Network operators have new options to weigh in their efforts to more efficiently manage the flow of traffic across multiple types of local networks, thanks to innovations from two vendors that take very different approaches to bandwidth allocation at edge points in broadband architectures.

CrossKeys Systems Corp.'s tack to ensuring consistent service to consumers and businesses involves a proprietary implementation of so-called soft-switch technology, which delivers commands to distribution points in the network based on constant evaluation of traffic usage at the edges.

The other approach, offered by Advanced Switching Communications Inc., relies on placement of new switching modules at the edges that are designed to reduce congestion at traditional switch locations.

"CrossKeys began as a provider of core switching technology in the local and long-distance telephone sectors, but it is now focusing on the edge as the point where the need for better bandwidth management is most acute," said Steve Getz, vice president of the firm's broadband-access group.

"Our new system is designed to meet the needs of cable operators, as well as local-exchange carriers and ISPs [Internet-service providers], in the delivery of high-speed data access to end-users," he added.

CrossKeys is bringing its "Dyband" edge-management solution to market after four years of development efforts aimed at providing a software system that would work as well with digital subscriber line as it does with cable, Getz said.

"Both of these network platforms have experienced wildly inconsistent demand patterns where the typical solution is to overallocate bandwidth to accommodate the spikes or risk disappointing and losing customers by setting rate caps," he added.

Allentown, Pa.-based Cross-Keys relies on a dynamic bandwidth-management solution that begins with monitoring the traffic flow at edge points such as DSLAMS (DSL-access multiplexers), ISP POPs (points of presence) and cable secondary hubs at a rate of 100 times per second.

If too many users are online at once, or a few users are consuming inordinate amounts of bandwidth, the system instantly detects the spiking traffic pattern and throttles down the throughput allocation to each end-user on a uniform basis.

Getz said the CrossKeys system can be set up to recognize various levels of service, so customers who are paying a premium for a certain guaranteed data rate are kept above the service-level threshold. The system comes with a user interface that provides information on the bandwidth usage of every user, he added.

ASC developed a new type of edge device designed to exploit the multiprotocol delivery capabilities of ATM (asynchronous transfer mode) in a way that reduces the number of links between end-users and core switching components.

Where CrossKeys targets cable, as well as other network-service providers, ASC concentrates on improving the allocation efficiencies within the traditional business-market domain, as well as the DSL segments that serve consumers and businesses.

ASC can give all types of network-service providers a low-cost means of using multiple protocols and delivery platforms to compete in the enterprise market, vice president of marketing Larry Kraft said.

"Today, most [LEC] services are provisioned over a TDM [time-division multiplex] architecture, which requires that an army of provisioners go through the allocation slots to find an available channel on the DACS [digital-access cross-connect], and then find a circuit between the DACS and the customer and get the customer connected," Kraft said. "It's a complicated, inefficient process that serves as a major bottleneck to provisioning broadband services."

ASC places one of several versions of its "MultiStream" boxes between the core backbone switch and the end-users, possibly alongside a central-office switch or positioned separately where CO switches aren't involved.

Andrew Cray, senior analyst at Aberdeen Group Inc., a market-research and consulting firm, said, "Frame relay is a service that is still growing rapidly, but, like other services, it needs to scale to support the astounding number of new applications that enterprises are introducing to their networks. The value of [the ASC MultiStream approach] is that it delivers a bandwidth boost for those customers, using the technology they are familiar with."

ASC, a three-year-old company based in Vienna, Va., has gone much further in penetrating the new edge-network-management market than CrossKeys, which only entered the market at the start of the month. But CrossKeys is close to announcing its first customers, and it is working closely with at least one cable customer to prove that its concept is a viable option in cable, Getz said.

"We've already demonstrated that you can throw open the throttle from a DOCSIS [Data Over Cable Service Interface Specification] 1.1 headend and not have to worry about any one point of overuse creating problems for the entire network," he added.

For cable operators seeking to expand beyond the consumer market and into the enterprise base, both vendors offer potentially important pieces to the puzzle of bandwidth management.

Without such solutions-as recent congestion and management issues surrounding the implementation of DOCSIS suggested-the cable industry will be hard-pressed to compete in the fast-moving broadband market for new applications and services.