This counter tracks the number of END PDUs received on this port, per the description, indicating the far end has initiated termination of the SSCOP signaling link itself. Since this brings down all Q.93b signaling for every SVC on this port at once (not just one call), a nonzero count here that correlates with a spike in svcAtmConfigQ93bActiveConns dropping to zero would confirm the far end tore down the whole link rather than the calls failing individually. Frequent unplanned END receipt from the same peer is worth raising with that peer's operator.