Cisco makes routing software more resilient

Cisco Systems Inc. this week updated its routing software to provide service providers with an alternative bandwidth protection mechanism to SONET/SDH.

Called Multiprotocol Label Switching (MPLS) Bandwidth Protection, the extension to Cisco's IOS software uses MPLS Traffic Engineering Fast Reroute and an application called Tunnel Builder Pro to increase network bandwidth protection and resiliency.

MPLS Bandwidth Protection helps service providers minimize and eliminate non-productive redundant circuits, and offer "carrier-class" service-level agreements (SLA), Cisco says.

"This gives the customer the ability to much more easily deploy Fast Reroute while preserving the failover of SONET/SDH," says Irwin Lazar, an analyst at The Burton Group Corp. in Sterling, Va. "They no longer have to have links sitting idle waiting for a break to happen."

MPLS is designed to provide traffic engineering capabilities to make networks more efficient and reliable, and to optimize network resource utilization and traffic performance. Currently, MPLS Traffic Engineering computes best available paths.

MPLS's Fast Reroute Link and Node protection feature -- which is designed to protect against link and node failures -- does not provide networkwide protection by itself, Cisco claims.

To support bandwidth protection, Cisco has added features to Fast Reroute Link and Node protection. They include the Tunnel Builder Pro application, which computes backup tunnels for bandwidth protection using an algorithm called Hybrid Optimization. Hybrid Optimization backs up bandwidth irrespective of the number of traffic engineering tunnels in the network, Cisco says.

Tunnel Builder Pro, developed by Cisco with Parc Technologies, uses a client-server architecture. The client is an HTML-based Java applet that can run on a standard Web browser, while the server communicates with Cisco routers to configure and monitor them for MPLS Traffic Engineering.

Another new feature in Fast Reroute Link and Node protection is support for Resource Reservation Protocol (RSVP) Hello packets, which are used as a failure detection mechanism for interfaces other than Packet-over-SONET -- such as Fast Ethernet and Gigabit Ethernet.

MPLS Bandwidth Protection has already garnered the interest of one service provider, even though the provider has not deployed the new software.

"We have not yet deployed the bandwidth protection capabilities. However, MPLS/TE with Fast Reroute and off-line computation tools such as Tunnel Builder Pro are major components in our current thinking to achieve QoS based traffic optimization across the entire network," says Joe Fusco, director of Private IP Services at Infonet. "We think that these technologies would allow for improved ability to manage a multi-class network within statistical QoS targets and aid in resolving performance issues. Infonet is co-authoring an IETF draft that defines the protocol between the routes and such off-line computation tools so this fits in well with our plans."

Infonet's hesitancy in implementing MPLS Bandwidth Protection is due to the software sensitivity of its network, Fusco says. The service provider recently revised its Cisco IOS software for support of Class of Service and is cautious about another change at this point.

"With a network with over 550 global corporate IP VPNs running on it, every change is undertaken with great caution," Fusco says. "We cannot afford to deploy until we have thoroughly regressed the IOS to ensure it doesn't break any of our current services."

Nonetheless, Infonet expects to begin deployment of MPLS Bandwidth Protection next year.

Cisco MPLS Bandwidth Protection is available now.

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