This reports the unique index identifying a row in the maintenance domain table, a simple table-key value used to reference a specific maintenance domain entry rather than carrying any descriptive information itself. An admin primarily uses this as the join key when correlating a maintenance domain's level, name, and service count together, or when other tables in the MIB reference a maintenance domain by this index. For example, automation building a network topology map would use cienaCesCfmMaintenanceDomainIndex to link a maintenance domain's name and level to the services and MEPs that reference it elsewhere in the MIB.