Many service provider service level agreements (SLAs) depend on the
ability to measure and monitor performance metrics for packet loss
and one-way and two-way delay, as well as related metrics such as
delay variation and channel throughput. This measurement capability
also provides operators with greater visibility into the performance
characteristics of their networks, thereby facilitating planning,
troubleshooting, and network performance evaluation. This document
specifies protocol mechanisms to enable the efficient and accurate
measurement of these performance metrics in MPLS networks. [STANDARDS-TRACK]