Traffic Distribution over Equal-Cost-Multi-Paths using LRU-based Caching with Counting Scheme

Abstract

In order to reduce network congestion and fully use link bandwidth, when there are Equal-cost-multi-paths (ECMPs) between a forwarding node and a destination subnet, traffic load should be balanced among ECMPs and packets of the same TCP flow should reach destination host in the same order. An algorithm called LRU1- based Caching with Counting (LCC) is proposed. Packet length differentiation is considered to achieve load balance by adapting a counter for each ECMP, and counter overflow is solved by relative counting and restrictions. UDP packets only need to be concerned to achieve load balance. Furthermore, flow delay differentiation forwarding to different hosts of the same destination subnet is transformed to entries in cache invalided time period difference. Simulation shows that when delay differentiation among ECMPs is not significant, storage requirement is small, only one cycle is needed for each cache lookup, load balance is near optimal, and only 2% of packets are out of order.