This counts frames on this circuit that were dropped by the switch's rate-enforcement mechanism because the customer sent more traffic than the circuit's committed plus excess allowances permit. An admin seeing this counter climb steadily, not just during brief spikes, has hard evidence a customer is consistently oversending relative to their provisioned CIR and may need a rate upgrade rather than continued dropped traffic. For example, a circuit provisioned at 64 kbps CIR showing thousands of cktInDiscards per hour during a bulk transfer indicates the customer's actual demand regularly exceeds their contracted rate.