Improving the Performance of TCP on guaranteed bandwidth connections

Abstract

This paper discusses the performance of the Transmission Control Protocol under two aspects: First, the future Internet will provide some kind of service differentiation and bandwidth guarantees. Nevertheless, TCP connections often cannot fully exploit the reserved bandwidth over time. The congestion control mechanisms like slow start and congestion avoidance have to be revised in the context of guaranteed services, where no congestions occur for special flows.

Second, short-lived TCP connections have become more and more important in the Internet. Short-lived connections are needed in transaction-oriented network applications and client-server scenariors; a typical example is the common use of the World Wide Web. TCP has typical performance flaws in these cases.

Former approaches of improving the performance of TCP did not succeed because their objective was the adaption of all involved TCP stacks. This leads to a change in every TCP stack in the Internet — at least 80 millions hosts within nowadays. In this paper another way has been chosen: only one host within a connection will be modified, particularly with regard to client-sever communication. With this context, several modifications to improve TCP's performance with given bandwidth guarantees and their evaluation will be presented in this paper.