10.3.2 IEEE 802.1ag Definitions
Maintenance Domain (MD):
Management space on a network that is owned and operated by a single network provider.
There is a maintenance level (from 0 to 7) to define the hierarchical relationship between domains. Maintenance domains
can be nested but never intersect. MD is defined by Operational or Contractual Boundaries (e.g., Customer, Service
Provider, Operator).
Maintenance Association (MA):
Association of Maintenance. Elements that comprise the Maintenance domain.
Maintenance Elements can either be MEPs (End Points) or MIPs (Intermediate Points):
MEPs are at the edge of the network. They can generate and respond to OAM messages. A point-to-point EVC has
only 2 MEPs, a multi-point EVC has multiple MEPs.
MIPs are located between the MEPs and can be used to isolate network problems. MIPs cannot generate OAM
messages but can respond.
Maintenance Level:
Identifies the network hierarchy. Higher Level = Largest network. Level information present in all OAM
PDU frames.
Level 0,1,2 = Operator domain
Level 3,4 = Service Provider domain
Level 5,6,7 = Customer domain
Some terms differ between the two protocols. The chart below describes the differences.
Definition Equivalencies
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