Defines a table for storing the results of an OAM 'lspTraceRoute' or
'p2mpLspTrace' probe operation when a Downstream Mapping TLV was
returned. Each row represents a single downstream label within a
returned downstream L2 mapping TLV.
An entry in this table is created when the result of an OAM
'lspTraceRoute' or 'p2mpLspTrace' probe is determined.
An entry is removed from this table when its corresponding
tmnxOamTrCtlEntry is deleted.