Evaluating Performance Among Different TCP flows in a Differentiated Services Enabled Network

This paper examines the interaction among short-lived and long-lived TCP flows in a test network that can be operated as an ordinary best effort or as a Differentiated Services (DS) enabled network, and shows how TCP service can be improved by isolating TCP flows based on their different characteristics. The target of the measurements was to investigate the interaction among TCP flows having similar priority classification but different traffic volume. The flows are originating from a single customer network and destined to the ISP’s DS enabled network. With our measurements, we have shown the benefits resulting from the separation of such TCP flows into two categories: large-volume long-lived FTP-type flows and small-volume short-lived interactive (e.g. HTTP-type) flows. For FTP flows goodput was increased and for HTTP flows decreased transfer time was obtained. 1