This is a cumulative count of frames received by this specific station since the last reset, the frame-level counterpart to this station's packet and character counters. An admin compares this against the station's packet count to spot unusual link-layer framing behavior specific to one device on a shared line, rather than a port-wide condition. For example, a single station showing disproportionately high FrameInTot relative to PktInTot, while its port-mates don't, would point at that one device's own interface rather than a shared-line problem.