This read-only Counter32 counts receive overrun events on a particular HDLC-like interface, occurring when incoming data arrives faster than the receiving hardware buffer can process it. An admin watches this counter to catch a receiver that's being overwhelmed, often a sign the interface's clock rate or buffering is undersized for the offered traffic load. For example, a growing overrun count on a high-speed leased-line interface might prompt the admin to check for a clocking mismatch or insufficient buffer allocation on that port.