Buffer Sizing For Core Routers

Due to the technology development disproportion of optical fiber transmission and electronics, the core router as network core node has become the main bottleneck in the progress of modern networks. As Storage and forwarding equipment, the Router's buffer size is one of the most important factors which influence router's performance.This paper aims to size buffers for core routers and is according to the requirements on one of key projects of the National High-Tech Research and Development Program of China (863 Program) named "The basic platform and experiment system for terabit scalable high performance IPv4/v6 routers". This dissertation tries to find out a new rule to sizing buffers for core routers, based on the analysis and comparison of router's buffer sizing rules in existence. Being dead against the deficiency such as consumption, cost, delay, loss rate, utilization, and considering the loss rate and utilization. This paper analyzes the buffer sizing for core routers. Considering the situation that the link utilization is very low in backbone networks, we propose a new rule of sizing buffers. The results of simulation show the new rule is better than the current ones. This new rule applied to Terabit Router successfully and reduced the cost of the project. The key contributions of this dissertation include:1. This dissertation briefly compares the different results and proposals of routers buffer sizing, and point out the deficiencies in consumption, cost, delay, loss rate and utilization. Giving direction, supplying references and new methods for the dissertation.2. In consideration of the low link utilization and the large volume of TCP flows in current backbone networks, we propose a more realistic rule for sizing the buffers of backbone routers, which take into account several performance metrics such as packet loss rate and link utilization simultaneity.3. This paper verifies the conclusions by using ns2 network simulator and giving strong proof to the conclusions.4. Based on the forementioned analysis and according to the requirements of 863 Terabit Router project and other factors, we present a scheme of buffer size, applying the scheme to Terabit Router successfully and reducing the cost of the project.