Configuring Ethernet OAM
Ethernet OAM Overview
OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
page 35-3
Ethernet OAM Overview
Ethernet OAM focuses on two main areas that service providers require the most and are rapidly evolving
in the standards bodies:
•
Service OAM (IEEE 802.1ag and ITU-T Y.1731)—for monitoring and troubleshooting end-to-end
Ethernet service instances.
•
Link OAM (IEEE 802.3ah EFM Link OAM)—for monitoring and troubleshooting individual Ethernet
links.
These two protocols are both unique and complimentary. For example, Service OAM may isolate a fault
down to a specific service, but to determine exactly where the fault occurred within the network infra-
structure might also require the use of Link OAM.
Ethernet Service OAM
Ethernet Service OAM allows service providers to manage customer services end-to-end on a per-service-
instance basis. A customer service instance, or Ethernet Virtual Connection (EVC), is the service that is
sold to a customer and is designated by a VLAN tag on the User-to-Network Interface (UNI).
Elements of Service OAM
•
Maintenance End Points (MEPs) and Maintenance Intermediate Points (MIPs)
– MEPs initiate OAM commands. MEPs prevent leakage between domains.
– MIPs passively receive and respond to OAM frames.
•
Virtual MEP: creates an UP MEP on a virtual port.
•
Maintenance Association (MA) is a logical connection between two or more MEPs.
•
Point-to-point MA: logical sub-MA component only between two MEPs MA.
•
Maintenance Domain: One or more MAs under the same administrative control.
•
Maintenance Domain Levels: There are eight levels defined in 802.1ag:
– levels [5, 6, 7] are for customers
– levels [3, 4] are for service provider
– levels [0, 1, 2] are for operators
Multiple levels are supported for flexibility.
•
Mechanisms: continuity check (CC), loopback, link trace
•
Remote Fault Propagation (RFP): Propagates connectivity fault events into the interface attached to a
MEP.
CFM Maintenance Domain
CFM uses a hierarchical Maintenance Domain (MD) infrastructure to manage and administer Ethernet
networks.
•
Each domain is made up of Maintenance Endpoints (MEPs) and Maintenance Intermediate Points
(MIPs).