Towards High-performance Flow-level Packet Processing on Multi-core Network Processors

There is a growing interest in designing high-performance network devices to perform packet processing at flow level. Applications such as stateful access control, deep inspection and flow-based load balancing all require efficient flow-level packet processing. In this paper, we present a design of high-performance flow-level packet processing system based on multi-core network processors. Main contribution of this paper includes: a) A high performance flow classification algorithm optimized for network processors; b) An efficient flow state management scheme leveraging memory hierarchy to support large number of concurrent flows; c) Two hardware-optimized packet ordering strategies that preserve internal and external per-flow packet orders. Experimental results show that: a) The proposed flow classification algorithm, AggreCuts, outperforms the well-known HiCuts algorithm in terms of classification rate and memory storage; b) The presented SigHash scheme can manages over 10M concurrent flow states on IXP2850 NP with extremely low exception rate; c) The performance of internal packet ordering scheme using SRAM queue-array is about 70% of that of external packet ordering scheme realized by ordered-thread execution.