3ah
Misc. transport standards
Discovery
Link monitoring
Remote failure indication
Remote, local loopback
Fault isolation
Performance monitoring
Source: ADVA Optical Networking
90 Chapter 2
detected and ensures that other devices that receive the same alarm suppress
duplicate notifications (very much like what??™s available on SONET and ATM).
?– Traceroute This is a simple ???ping-like??? function that basically tests a specific
multihop path across a Service Provider network (and likely across multiple operators??™
domains).
?– Performance monitoring This functionality allows measurement of specific
SLA parameters relating to a particular service instance (EVC) such as delay
encountered, loss packets, jitter (or differential delay), and availability over a period.
These measurements are on an end-to-end basis and closely reflect the performance
of an actual service.
At the data-link layer, performance monitoring is limited across a physical link. This
section briefly introduces some of the key OAM standards and highlights their essential
characteristics.
IEEE 802.1ag Connectivity Fault Management (CFM) The IEEE 802.1ag is expected
to be ratified in 2007 and enables Service Providers to manage individual EVCs, representing
specific Ethernet services.
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