This read-write parameter defines the size of the replay protection window in packets for 802.1AE MACsec interfaces, with a default value of 0 (no replay protection). The window size determines how many out-of-order packets the receiver will accept before discarding them as replayed; a larger window allows more packet reordering but increases vulnerability to replay attacks. Security engineers configure this to balance between legitimate packet reordering (from redundant paths or traffic engineering) and protection against malicious packet replay attacks.