Abstract: Methods and systems are disclosed for anti-replay protection for network packet communications. A scorecard is stored that includes packet sequence numbers for received packets associated with a network packet flow. For each received packet, an anti-replay unit accesses the scorecard for an initial check to determine if the current packet represents a late packet and/or a replay packet. After further processing, the anti-replay unit accesses the scorecard for a final check to determine if the current packet represents a replay packet. For one embodiment, the initial check uses a first window of packet sequence numbers, and the final check uses a second window of packet sequence numbers that is larger than the first window. For further embodiments, multiple processing units operate in parallel to process received packets and to share the anti-replay unit, and each processing unit requests initial and final checks for received packets it processes.

Abstract: Methods and systems are disclosed for anti-replay protection for network packet communications. A scorecard is stored that includes packet sequence numbers for received packets associated with a network packet flow. For each received packet, an anti-replay unit accesses the scorecard for an initial check to determine if the current packet represents a late packet and/or a replay packet. After further processing, the anti-replay unit accesses the scorecard for a final check to determine if the current packet represents a replay packet. For one embodiment, the initial check uses a first window of packet sequence numbers, and the final check uses a second window of packet sequence numbers that is larger than the first window. For further embodiments, multiple processing units operate in parallel to process received packets and to share the anti-replay unit, and each processing unit requests initial and final checks for received packets it processes.