This counter reports the total bytes of ingress traffic on this PM instance that were accepted as in-profile -- conforming to the service's committed rate -- during a completed 15-minute window (for example 14:30-14:45). This is the figure that represents legitimate, fully-forwarded revenue traffic for this service over that completed 15-minute interval, so comparing it against the port's configured committed rate for that same span tells you how close to its contracted capacity the service is actually running. For instance, a service provisioned for a 10 Mbps CIR that accumulates close to the theoretical maximum accepted-byte count for that completed 15-minute interval is running essentially at its committed ceiling, worth flagging before a customer calls in about slowness.