Rate controls in standard transport layer protocols

Abstract

Flow control mechanisms in current datagram switching networks currently have several responsibilities, including avoiding congestion and avoiding overruns. In particular, networks and end-systems rely heavily upon the window mechanisms specified in current transport protocol standards such as TCP and TP4. These responsibilities will increase in future systems. This paper develops a connection model in order to assess the extent to which transport protocol data rates can be controlled using this available mechanism. Under very low delays, window-based flow control is not effective in slowing the rates at which a sender introduces data to the network or internetwork. Therefore, direct rate controls will be needed to enforce policies or to optimize performance across a variety of users and media.