Network Interface Power Management and TCP Congestion Control: a Troubled Marriage

Abstract

Optimizing the tradeoff between power saving and Quality of Service (QoS) in the current Internet is a challenging research objective, whose difficulty stems also from the dominant presence of TCP traffic, and its elastic nature. In a previous work we have shown that an intertwining exists between capacity scaling approaches and TCP congestion control. In this paper we investigate the reasons of such intertwining, and we evaluate how and how much the dynamics of the two algorithms affect each other’s performance. More specifically, we will show that such an interaction is essentially due to the overlap of the two closed loop controls, with different time constants.