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 the current, still-filling 15-minute window. This is the figure that represents legitimate, fully-forwarded revenue traffic for this service over the still-accumulating current 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 the still-accumulating current interval is running essentially at its committed ceiling, worth flagging before a customer calls in about slowness.