The line group entry ID is the LgId defined in the Line Group Redundancy MIB. LgId identifies the physical line or line group (primary and redundant secondary) used for data and voice traffic. This is a unique number that is assigned when a line redundancy group is provisioned - this allows the operator to locate the physical lines (defined by the line group entry ID) used by the subscriber. This is used as an index into the subInfoTable, subDataConnectionTable and the subVoiceConnectionTable allowing a subscriber own multiple lines. Required for row creation.