This read-only counter tracks the number of incoming point-to-point and point-to-multipoint SVC/SPVC call attempts on this interface that failed due to address filtering. It lets an admin identify how many inbound call failures are specifically caused by the switch's configured address filters blocking the caller. For example, a rising count here after tightening address-filter policy would confirm the filters are actively rejecting calls as intended, or unintentionally blocking legitimate callers if the count is higher than expected.