Cisco grabs unused capacity for recovery

Service providers now can always have enough bandwidth in reserve to recover from failures, according to Cisco Systems Inc., which on Monday introduced software designed to deliver on that promise.

Cisco MPLS (Multiprotocol Label Switching) Bandwidth Protection can automatically analyze the configuration of a network and find an alternative path with equal capacity for every path being used. Then, if a router or the physical link between two routers fails, the other routers can automatically send traffic over that alternative path.

This capability could help telecommunications carriers and Internet service providers keep their networks running smoothly, making possible performance-sensitive services such as voice over IP, at lower capital and operational cost, according to Cisco.

The software, available now, works with a draft standard of the Internet Engineering Task Force (IETF) called MPLS Traffic Engineering Fast Reroute. However, currently it works only in networks of Cisco routers. Cisco has submitted the specifications for its technology to the IETF for consideration as a possible standard, according to Amrit Hanspal, a product manager at Cisco, in San Jose, Calif.

Bandwidth Protection is intended to overcome the necessity to deploy a redundant physical link of equal capacity for every primary link on a network. This is the most common way of ensuring quick recovery from failures on SONET/SDH (Synchronous Optical Network/Synchronous Digital Hierarchy) networks, but it requires the carrier to pay for an entire link that it only uses in case of a failure, Hanspal said.

The new software can find the necessary bandwidth for a full recovery on the links the carrier is already using, which on most Cisco customers’ carrier networks are being filled to only 50 per cent to 60 per cent capacity, he said.

Routing protocols typically find and use the shortest logical path between two routers – that is, the one with the fewest intervening routers. MPLS Traffic Engineering Fast Reroute helps routers quickly find alternatives if the shortest route should fail. Cisco’s Bandwidth Protection feature adds the capability to measure the available bandwidth on each possible path in the network so the traffic can be sent down a path with equal capacity if the primary one fails.

Those calculations need to change every time a new router or port is activated. Administrators can set the software to recalculate alternative routes at any regular time interval, or to suggest routes that the administrator can then approve or reject.

The Bandwidth Protection system consists of two elements: Tunnel Builder Pro, an application for calculating routes that can run on a Sun Microsystems Inc. Solaris or Microsoft Corp. Windows server, and the latest version of Cisco IOS (Internetwork Operating System) software.

Infonet Services Corp., which operates an all-Cisco global private IP network, wants to deploy the Bandwidth Protection system so it can better serve customers in case of a network failure. Different classes of service are offered over different MPLS tunnels on the IP network, and this technology will allow Infonet to set up multiple backup tunnels that deliver the correct classes of service, said Joe Fusco, director of private IP network services at Infonet, in El Segundo, Calif. Capacity utilization on Infonet’s network averages about 20 per cent to 30 per cent, he said. The overall goal is to bring service back up to promised levels as quickly as possible after a failure, he said.

Carriers need to be able to make their IP networks more reliable so they can start using them for more critical – and more profitable – services, said Mark Bieberich, an analyst at The Yankee Group, in Boston.

“The IP business model is flawed today,” Bieberich said. IP traffic is growing by 100 per cent per year, while revenue from IP services is growing at only 15 per cent, he said. Part of the reason is that many carriers are still using other kinds of networks for high-priced data services to corporations that need high reliability.

“Service providers are very antsy about putting their mission-critical traffic on an IP infrastructure,” he said. For example, the use of IP VPNs (virtual private networks) in place of dedicated private connections is not growing at as rapid a rate as expected.

The need for both greater stability and lower carrier costs probably will drive other vendors to develop similar systems, and eventually those systems will be standardized through the IETF, Bieberich said. In the meantime, there are many service providers that use exclusively Cisco routers in their data networks and could take advantage of the new software soon, he said.

However, Bandwidth Protection is only one part of the solution to problems such as the approximately nine-hour slowdown on WorldCom Inc.’s UUNet backbone this week. WorldCom believes the failure stemmed from problems loading software onto its routers. Router software also is gradually becoming more robust, Bieberich said.

Enhancements to IP over the next few years should eventually make it as viable for corporations as established technologies such as Frame Relay and ATM (Asynchronous Transfer Mode), said Mark Seery, an analyst at RHK Inc., in South San Francisco, Calif.

“Two to five years from now, we’ll look back and say, ‘IP networks are really a different animal now,'” Seery said.

Pricing of the Cisco MPLS Tunnel Builder Pro 2.0 software varies depending on the number of routers that will use it in a network. It ranges from US$300,000 for as many as 25 routers to US$1.1 million for an unlimited number of routers.