ITU-T Y.1731 performance monitoring provides standards-based Ethernet performance monitoring that encompasses the measurement of Ethernet frame delay, frame delay variation, and frame loss and throughput as outlined in the ITU-T Y-1731 specification and interpreted by the Metro Ethernet Forum (MEF). Service providers offer service-level agreements (SLAs) that describe the level of performance customers can expect for services. This document describes the Ethernet performance management aspect of SLAs.
It would allow you to pinpoint the cause of outages, you could easily tell if the problem was routing or the actual circuit.
You could also use SNMP to measure jitter/delay on the link to ensure SLA targets are met.
