Efficient Computation of Queueing Delay at a Network Port From Output Link Packet Traces
Source: University of California
Current Internet core routers provide enough buffer capacity at each output port to keep the link busy for 250 msec. to avoid disrupting TCP flows because of dropped packets. Since link speeds are rising much more quickly than the availability and cost-effectiveness of large high-speed memories, there is now significant interest in reducing these buffers. Queue Inferencing (QI) - a passive, external method for calculating the time-dependent queue lengths and waiting times using start/end service event timestamps - is an ideal tool for studying the effects of such buffer size reductions because it can be applied in situ to packet traces collected from existing equipment carrying live traffic without any service disruptions.