The Multiprotocol Label Switching standard is coming into vogue as a way to provide SONET-like resiliency in packet networks.Created five years ago to provide more deterministic behavior in IP networks, MPLS over the years has become the Swiss Army knife of networks. It's touted as a way to consolidate ATM, frame relay and IP networks, deliver VPN services, guarantee quality-of-service and route around failures.It's this last aspect that's garnering the most recent attention. Three vendors have announced enhancements to their MPLS software offerings designed to harness the MPLS standard's Fast Reroute capability to enable recovery of IP and Ethernet link failures in milliseconds.MPLS Fast Reroute is designed to provide protection from link and node failures. Riverstone, Atrica and Cisco, however, are enhancing the Fast Reroute in their products to provide IP and Ethernet resiliency that equals or surpasses that of SONET, which can recover in 50 milliseconds."MPLS Fast Reroute provides service providers with something that's always been available in the voice world," says Mark Bieberich, an analyst with The Yankee Group in Boston. "Something equivalent in the IP world has always been something that has eluded IP network managers, and something that's contributed to the unpredictability and the instability of IP networks. It's part of a larger equation that will advance the state of IP such that service providers will want to start putting mission-critical traffic on their IP backbones and roll out services with stricter (service-level agreements)."Riverstone this week unveiled its version of MPLS Fast Reroute for its metropolitan-area network routers. In addition to giving SONET-like resiliency to IP networks, Riverstone's software is intended to enable service delivery guarantees, and enhance a carrier's ability to assure service levels and increase revenue with the delivery of VPNs.Riverstone's Fast Reroute technology enables routers along a MPLS path to divert traffic around points of failure in tens of milliseconds, the company claims. Riverstone's software also enables the creation of secondary MPLS paths to which traffic is automatically transferred in the event of a network outage, the company says.Fast Reroute is a recent addition to start-up Atrica's lineup of optical Ethernet switches. The vendor this week announced a win with France Telecom for transparent LAN, Ethernet private line and Internet access services that will be anchored by Atrica's A-8800, A-8100 and A-2100 switches and access gear.Atrica's MPLS Fast Reroute software will help ensure 50 millisecond link restoration and "hard" quality-of-service guarantees for MPLS Label Switched Paths transporting those services, says Nan Chen, Atrica director of product marketing.For networkwide resiliency, Cisco last week rolled out MPLS Bandwidth Protection, an extension to Cisco\u2019s IOS routing software that uses Fast Reroute along with an application called Tunnel Builder Pro. MPLS Bandwidth Protection helps service providers minimize or eliminate non-productive redundant circuits, and offer carrier-class service-level agreements, Cisco says.Tunnel Builder Pro computes backup tunnels for bandwidth protection. Another new feature in Cisco's Fast Reroute software is support for Resource Reservation Protocol Hello packets, which are used as a failure-detection mechanism for interfaces other than packet over SONET - such as Fast Ethernet and Gigabit Ethernet.Despite the recent vendor activity around MPLS Fast Reroute, analysts offer a caveat. Many implementations are vendor-specific, which means that even though MPLS is an emerging standard, vendors will interpret it as befits their profiteering motives."Potential customers of Ethernet router MPLS technologies should carefully watch the progress of standardization efforts to ensure consensus is forming before making any investments that might otherwise become stranded, and should bear expected timelines for finalization of standards in mind," states Current Analysis Analyst David Dunphy in a recent report. "Service providers should push Ethernet router vendors for detailed explanations of their MPLS leadership positioning, and bear in mind the relatively small size of the market at this point. Customers should compare the drafts supported by various competitors to determine how much current differentiation actually exists and how much is positioning around fairly similar support, based on the same IETF documents."