underlyingConnectionNames

Syntax: SET OF ObjectInstance
Meaning: For a port object, this is always the null set.
For a logicalLink object, this represents the port that the logicalLink is subordinate to. If unknown, the null set is provided.
Source: For non-switched PUs, this is always the port object representing the LINE that the physical unit is defined under. For switched PUs, this attribute will not be known if the PU is not dialed.
Operations: GET
Attribute of: logicalLink
port