This read-only object reports the status of X.21/HSSI lines as a bitmap using the hex values 0x01, 0x02, and 0x04, though the specific meaning of each bit is not detailed in the available description. An administrator would use this value in conjunction with vendor documentation to interpret the exact EIA control-lead status being reported. For example, a network management script would still be able to detect a status change by watching for any transition in this value, even without full bit-level documentation.