A technique used in ATM networks at the switch level that applies a sustained cell flow rate to bursty traffic. Incoming data flows into a buffer (the "bucket"), then "leaks" out at a steady rate, which is designated as constant bit rate (CBR) traffic. In the event the in-flow exceeds the negotiated rate for a certain time, the buffer will overflow. At that point, the switch examines the Cell Loss Priority (CLP) bit in each cell, and low-priority cells are discarded and retransmitted by the originating device. See leaky bucket counter.