This table contains information on which
cContextMappingVacmContextName is mapped to
which bridge domain.
A Bridge Domain is one of the means by which it is possible
to define an Ethernet broadcast domain on a bridging device.
A network can have multiple broadcast domains configured.
This table helps the network management personnel to find
out the details of various broadcast domains configured
in the network.
An entry need to exist in cContextMappingTable, to create
an entry in this table.