This read-only string reports the PVC's current operational state in PVCR mode, one of OFF (inactive), CALL (waiting for the network's active signal), TEST, or DATA (actively passing traffic). An administrator watches this to know at a glance whether a given circuit is actually carrying user data. For example, a PVC stuck in CALL state instead of progressing to DATA would tell the administrator the circuit is failing to receive an active signal from the network and needs carrier-side attention.