Understanding the throughput of Transmission Control Protocol

Supervisor: Dr Richard Clegg

Research group(s): Networks

The TCP protocol governs the majority of traffic in the internet today. In its modern design TCP responds to loss (and delay) by slowing its rate and this is intended as the primary means for throughput control in the network. However, in the modern internet ecosystem TCP throughput is governed by a number of other systems: Video streaming sites deliberately throttle bandwidth so that users only download the next few seconds of a video, other sites have a model where paying users get faster downloads so deliberately throttle most traffic. There is good evidence that the majority of traffic on the modern internet is, in fact, not governed by TCP mechanisms at all but by the application, host or network. [See "On rate limitation mechanisms for TCP throughput: a longitudinal analysis" Araujo et al Computer Networks 2017]. This work will investigate further this hypothesis and the implications if TCP is no longer the dominant force controlling network traffic.