Routers With Very Small Buffers: Anomalous Loss Performance for Mixed Real-Time and TCP Traffic

The past few years have seen researchers debate the size of buffers required at core Internet routers. Much of this debate has focused on TCP throughput, and recent arguments supported by theory and experimentation suggest that few tens of packets of buffering suffice at bottleneck routers for TCP traffic to realise acceptable link utilisation. This paper introduces a small fraction of real-time (i.e. open-loop) traffic into the mix, and discovers an anomalous behaviour: In this specific regime of very small buffers, losses for real-time traffic do not fall monotonically with buffer size, but instead exhibit a region where larger buffers cause higher losses.