SONET - which stands for synchronous optical network - is the US standard for connecting fibre-optic transmission systems. SDH is the European equivalent.
Cisco has worked with Multiprotocol Label Switching (MPLS) for some time, to provide improved network efficiencies and a cheaper alternative to SONET/SDH. Now Cisco MPLS Bandwidth Protection, the extension to the company'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 minimise and eliminate non-productive redundant circuits, and offer "carrier-class" service-level agreements (SLA), according to Cisco.
"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. "They no longer have to have links sitting idle waiting for a break to happen."
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, so 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, which backs up bandwidth irrespective of the number of traffic engineering tunnels in the network.
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.
Cisco MPLS Bandwidth Protection is available now.