Small-buffer networks

Today, because of TCP dynamics, Internet backbone routers hold large packet buffers, which significantly increase their power consumption and design time. Recent models of large-buffer networks have suggested that these large buffers could be replaced with much smaller ones. Unfortunately, it turns out that these large-buffer network models are not valid anymore in small-buffer networks, and therefore cannot predict how these small-buffer networks will behave. In this paper, we introduce a new model that provides a complete statistical description of small-buffer Internet networks. We present novel models of the distributions of several network components, such as the line occupancies of each flow, the instantaneous arrival rates to the bottleneck queues, and the bottleneck queue sizes. Later, we combine all these models in a single fixed-point algorithm that forms the key to a global statistical small-buffer network model. In particular, given some QoS requirements, we show how this new model can be used to precisely size small buffers in backbone router designs.