This sets what percentage of 'RED' traffic, frames exceeding even the excess burst allowance, the network will still admit during non-congested periods, computed relative to the combined Bc+Be+allowed-RED total per the given formula, giving the admin a knob to decide how strictly over-limit traffic is penalized versus given a pass when the network has spare capacity anyway. An admin on an oversubscribed network might lower this from the generous 100% default to reduce how much clearly out-of-contract traffic gets carried even when things look quiet. For example, lowering cktRedFrPcnt to 50 on a circuit means only half of its RED-classified frame bits get admitted even during quiet periods, giving the network some cushion against a sudden burst of legitimate traffic from other circuits.