This counter measures the number of ATM cells transmitted from the port with CLP (Cell Loss Priority) bit set to 1, meaning lower-priority traffic that can be dropped during network congestion without affecting critical services. Network engineers monitor this to understand how much non-critical traffic is flowing and whether congestion-control policies are dropping enough low-priority cells when the network gets busy. A high count combined with a low CLP=0 count (say, 50 million CLP=1 cells and only 5 million CLP=0 cells) means the network is prioritizing lower-priority traffic, which could impact performance of important applications.