Service providers have used SONET/SDH Automatic Protection switching for a fairly long time. SONET APS provides a very fast failover (in ~50ms) from primary circuit to protected circuit when links fail. This is a commonly used technique at SONET/SDH layer . However, this technique dictates certain topologies and requires circuit redundancies even in full mesh networks. With the recent development of MPLS Fast Re-route some of these protection switching capabilities can be brought up to layer 3 utilizing mesh configuration more efficiently. Using MPLS traffic engineering bypass or detour tunnels can be setup and traffic re-routed in very short time frame comparable to that of SONET APS. Not only that, some of these techniques can used in conjunction with planning tools to provide the ultimate solution, which is, protecting bandwidth in the presence of any network component failure.

This tutorial briefly discusses the SONET protection techniques and then explains in detail some of the MPLS fast re-route techniques such as link protection, node protection and path protection. It highlights the differences in each type of protection mechanism and discusses its scalability aspects. It also describes the problem of bandwidth protection and why it is a hard problem to solve and then discusses some possible solutions and its trade offs

Azhar Sayeed has more than ten years of networking and communications industry experience. As product line manager with the IOS Technologies Division, Cisco Systems, Mr. Sayeed is responsible for product management and rollout of Quality of Service (QoS) and Multi Protocol Label Switching (MPLS) features in Cisco IOSR software. Cisco IOSR software is the network system software that powers the majority of Cisco's hardware platforms.

Anna Charny received her Ph.D in Computer Science from MIT in 1998. She has been with Cisco since 1999, where she works as an architect in the area of QoS and MPLS Traffic Engineering. Prior to Cisco, Anna had worked for DEC and Cabletron, where she was involved in high-speed switch design, and ATM Traffic Management. She has published several papers in networking conferences and journals, has co-authored several IETF Drafts and RFCs as well as ATM Forum contributions, and has a number of issued patents and pending patent applications.