Delay based feedback, transport protocols and small buffers

In this article we work with the class of transport protocols that use queuing delay as a primary feedback signal for flow and congestion control. Our focus will be on this class of transport protocols operating over small buffered networks; i.e., buffers that are of the order of tens of packets. We show that the performance of Vegas and FAST can be very sensitive to the precise choice of small buffer size. With Reno and Vegas, or Reno and FAST, operating together we also exhibit that AIMD Reno dominates the dynamics of flow control. Some guidelines are suggested that could help design and enhance protocol performance in small buffered networks.