Router buffer sizing revisited: the role of the output/input capacity ratio

The issue of router buffer sizing is still open and significant. Previous work either considers open-loop traffic or only analyzes persistent TCP flows. This paper differs in two ways. First, it considers the more realistic case of non-persistent TCP flows with heavy-tailed size distribution. Second, instead of only looking at link metrics, we focus on the impact of buffer sizing on TCP performance. Specifically, our goal is to find the buffer size that maximizes the average per-flow TCP throughput. Through a combination of testbed experiments, simulation, and analysis, we reach the following conclusions. The output/input capacity ratio at a network link largely determines the required buffer size. If that ratio is larger than one, the loss rate drops exponentially with the buffer size and the optimal buffer size is close to zero. Otherwise, if the output/input capacity ratio is lower than one, the loss rate follows a power-law reduction with the buffer size and significant buffering ...

• Type: Conference
• Year: 2007
• Where: CONEXT
• Authors: Ravi S. Prasad, Constantine Dovrolis, Marina Thottan
• Keywords: Buffer Size, Computer Networks, CONEXT 2007, Output/input Capacity Ratio, Required Buffer Size