This counter tracks the number of END PDUs transmitted on this port, per the description, where END is the SSCOP message that gracefully terminates the signaling data link connection (as opposed to a single SVC being released). Because tearing down the whole signaling link takes every SVC riding on it down with it, a rise in this counter is far more consequential than a rise in svcAtmConfigQ93bNumReleasePdu and should prompt checking why the signaling channel itself is being closed rather than just individual calls. This is typically only expected during planned maintenance or card resets.