This counter tracks occurrences of loss of cell delineation (LOCD), meaning the receiver has lost the ability to correctly identify ATM cell boundaries within the SONET payload. Admins treat a nonzero LOCD count as a serious ATM-layer synchronization problem, more severe than isolated HEC errors, since it means cell boundaries themselves can't be reliably found. A rising LOCD count would prompt an admin to check for a fundamental signal or framing issue affecting this interface's ATM cell stream.