Analysis and performance evaluation of the EFCM common congestion controller for TCP connections

Today's standard TCP implementations perform congestion control separately for each connection of an end system. It is advantageous in terms of overall performance, e.g., throughput and (short-term) fairness, to share network information between several TCP connections of an end system by establishing a common congestion control. In this paper, we present a new common congestion-control approach called "ensemble flow congestion management" (EFCM). First, we describe the design constraints of EFCM. Then, we explain and analyze the EFCM control algorithms. After that, we investigate the performance improvement of EFCM compared to standard TCP congestion control under different network conditions. Simulations with EFCM show a considerable increase in throughput and (short-term) fairness without increasing the aggressiveness of a set of TCP connections-we also show this analytically using a fairness argument. The proposed EFCM controller algorithms are easy to implement and have a low additional complexity. (c) 2005 Elsevier B.V. All rights reserved.