57-3
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 57 Configuring Ethernet OAM and CFM About Ethernet CFM
As shown in Figure 57-2, domains cannot intersect or overlap because that would require management
by more than one entity, which is not allowed. Domains can touch or nest (if the outer domain has a
higher maintenance level than the nested domain). Nesting domains can be useful when a service
provider contracts with one or more operators to provide Ethernet service. Each operator has its own
maintenance domain and the service provider domain is a superset of the operator domains. Maintenance
levels of nesting domains should be communicated among the administrating organizations. CFM
exchanges messages and performs operations on a per-domain basis.
Figure 57-1 CFM Maintenance Domains
Figure 57-2 Allowed Domain Relationships
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Operator Domains
Service Provider Domain Level 6
Operator 1
PE 1CE 1 CE 2PE 2 PE 3 PE 4
Operator 2
MEP
Level 4 Level 4
Level 3
Level 2
MEP MEP
MIP
MIP MIP
MEP MEPMIP MIP
MIP MEP
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Scenario A:
Touching Domains OK Scenario B:
Nested Domains OK Scenario C:
Intersecting Domains Not
Allowed