This Counter64 tallies the total number of frames received at this circuit's ingress point and successfully forwarded onto the circuit, serving as the primary frame-count baseline against which the various discard and tagged counters (circuitInFramesDiscard, circuitInFramesTagged) are compared. An admin calculates this circuit's frame loss or non-conformance rate by comparing this total against circuitInFramesDiscard and circuitInFramesTagged, since both are subsets of frames that arrived at the same ingress point. For example, if this counter shows 10 million frames received while circuitInFramesDiscard shows only 500, the admin can compute a discard rate of roughly 0.005 percent, indicating the circuit's traffic contract is well matched to actual load.