Software defined backpressure mechanism for edge router

Increased network traffic has put great pressure on edge router. It tends to be more expensive and consumes more resources. Buffer is especially the most valuable resource in the router. Given the potential benefits of reducing buffer sizes, a lot of debate on buffer sizing has emerged in the past few years. The small buffer rule, for example, was challenged at edge router. Instead of buffer sizing, the goal of our work is to find out a way to relieve the pressure of edge router and logically enlarge its buffer size without incurring additional costs. In this paper, taking advantage of the global view of SDN, we proposed Software Defined Backpressure Mechanism (SD-BM) to alleviate the pressure of edge router. Particularly, we gave Refill and Software Defined Networking based RED (RS-RED) algorithm, which makes it possible to enlarge the network buffer logically and offloads traffic from busy egress router to free ingress devices. Simulation results show that it has comparable performance, both in time delay and loss rate, with edge router which has large buffer in traditional way. The results can have consequences for the design of edge router and the related network.