This PerfCounter64 counter reports the average bit rate after rate limiting in the downstream (N2A) direction (measured after the flow's rate limiter, so it reflects the shaped, delivered rate rather than raw demand). An admin compares it against the subscriber flow's provisioned capacity to see whether traffic is running near, over, or well under what the port or flow is supposed to carry. If cmFlowStatsABRRLN2A on flow 3 settles around 36 Mbps at the current interval, an operator sizing that flow for an upgrade has a concrete number to compare against its provisioned limit, rather than guessing from aggregate port utilization.