Research On Massive Flow Management Technology For High-speed Network

Network flow management serves as a basic function in many network equipments.With the rapid development of the flow scale, the operation efficiency of insert, serchand delete in the flow table decreases rapidly, which becomes a bottleneck of systemperformance. To solve this problem, this paper proposes two different kinds of flowtable model, named OL model and TL model, based on the conflict processingmechanism. We validate the performacne of flow management system by someexperiments based on multi-core network processor.This paper studies the models of OL and TL. In the the same condition of totaltable length, we analyze the variation of the flow table conflict proportion, the averageconflict depth, and the maximum conflict depth depend on the length of second hashtable in TL model.Based on the OL and TL model, we research the key technologies of OLSM andTLSM on the platform of multi-core network processor. The hash table of OLSM andTLSM is OL and TL respectively. We describe the algorithms of flow ID distribution,hash index calculation, flow table appending, searching, updating and the algorithm ofdetection and deletion of timeout flow in flow table.In order to meet the requirement for a larger scale flow management which mayturn up in future, we propose a flow management method combining hardware andsoftware system and study the scheme of system designing and its key technologies.The hardware module is realized on FPGA with multi-channel DDR3memory, whilethe software module is based on the platform of multi-core network processor. Besides,we difine the format of communication packet, explain the three kinds of data pathbetween these two modules. And then, we evaluate the system performance.This paper builds a flow management system test environment based on the OLand TL model, and inputs the data packet of the real network to OLSM and TLSMsystem. With the same condition of the total stream size and the total length of flowtable, we compare the OL and TL model on the aspects of flow table conflict proportion,average conflict depth, maximum conflict depth and rate of losing packet. Furthermore,we test the performance of TLSM and the experiment results show that the peakprocessing rate can get up to4.8Gbps.