Economical protection in MPLS networks

The growth of Multi-Protocol Label Switching (MPLS) as the emerging choice for provisioning and managing core networks has placed significant emphasis on MPLS based recovery mechanisms. The present global protection frameworks require extensive involvement of Label Switching Routers (LSRs) in the protection framework. The LSRs are involved in failure propagation and maintenance of information regarding upstream neighbors. This extensive involvement of the LSRs in the protection frameworks may become a scalability issue particularly in case of complex MPLS networks as a single failure may affect many Label Switched Paths (LSPs) and Path Switch LSRs (PSLs). The restoration time in the present frameworks is dependant on the length of the working path. This dependence leads to an increase in the number of PSLs required for effective protection, which thereby increases resource usage. The present frameworks also do not monitor the PSL or the backup path for fault notification—a feature that is important to ensure reliable protection frameworks. We propose an economical global protection framework that is designed to provide minimal involvement of intermediate LSRs, reduction in the number of PSLs, fast and cost-effective fault notification, and cost-effective fault monitoring of even the PSLs and recovery paths. q 2004 Published by Elsevier B.V.