Setting the MD Level

The Ethernet CFM service network is partitioned into maintenance levels. Each maintenance level is defined by the reach and scope of the organization which administers the network equipment. Higher maintenance levels exist at the edge of the network. Network customers typically own these higher levels. Lower maintenance levels typically reside closer to the network core, and are usually reserved for service providers or network operators. Maintenance levels are hierarchical in nature. Higher maintenance levels encapsulate lower maintenance levels.

CFM PDUs at a given level are distributed and processed among maintenance points within that specific domain. CFM PDUs from a domain that encapsulates a lower level domain, pass transparently through the enclosed lower level domain as they transit to the remote side of the domain they belong to.

Note

See Maintenance Domain Overview for a depiction of MD encapsulation. The customer equipment MD at level 5 encapsulates both the service provider (level 3) and network operator (level 2) MDs; the service provider MD at level 3 encapsulates the network operator MDs.

CFM PDUs from a lower level domain encapsulated by a higher level domain are restricted from exiting the domain. These CFM PDUs are filtered by maintenance points of the higher level encapsulating domain.

These rules for transport and containment ensure that domain management and administration is restricted to the responsible organization. It also ensures that information concerning either the enclosed or enclosing domain is restricted to that domain. This prevents the customer from learning details concerning the internal topology of the service provider and operators and service providers from learning details concerning the customer topology.

The maintenance level to be assigned to an MD is typically determined by the service provider in the service level agreement.

Use the level command in the default MD or MD configuration mode to specify the MD level.

This example shows how to configure the level to 5 for the myMD1 maintenance domain:

System(rw-config)->cfm md string-name myMD1
System(su-config-cfm-md.1)->level 5
System(su-config-cfm-md.1)->enable
System(su-config-cfm-md.1)->