Temporal and hitless path segment monitoring
The MPLS transport profile (MPLS-TP) is now being standardized to enable carrier-grade packet transport and complement converged packet network deployments. One of the most attractive features in MPLS-TP is OAM functions, which enable network operators or service providers to provide various maintenance characteristics, such as prompt fault location, substantial survivability, performance monitoring, and preliminary or in-service measurements, inherent in circuit-based transport networks. One of the important characteristics which are common in transport network operation is the fault location. A segment monitoring function of a transport path is effective in terms of extension of the maintenance work and indispensable particularly when the OAM function is effective only between end points. However, the current approach for the segment monitoring(SPME) has some fatal issues. This document elaborates on the problem statement on the path segment monitoring function. Moreover, this document also requests to add network objectives to solve or improve the issues and proposes to reconsider the new improved method of the segment monitoring. This document is a product of a joint Internet Engineering Task Force (IETF) / International Telecommunications Union Telecommunications Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and PWE3 architectures to support the capabilities and functionalities of a packet transport network.