TKN Technical Reports Series

Today’s standard Internet transport protocol implementations perform flow and congestion control separately for each data stream, in isolation from all other data streams. It is advantageous in terms of improving the overall performance of the data streams, i.e., the throughput and fairness, to reuse network information and—as an extension—to establish a common congestion control between some of the data streams of an end system. In this technical report, we describe the design goals and explain the algorithms of a common congestion control approach for TCP connections called ”ensemble flow congestion management” (EFCM). In addition, we investigate the performance gain of the EFCM approach compared to the standard TCP congestion and flow control under different network conditions. Simulations with the EFCM approach show a considerable increase in throughput and fairness without increasing the aggressiveness of a set of TCP connections; the effect on background traffic is also negligible. The proposed EFCM controller algorithms are easy to implement and have a low additional complexity