Quantifying responsiveness of TCP aggregates by using direct sequence spread spectrum CDMA and its application in congestion control

In this paper, we introduce the notion of responsiveness for TCP aggregates and define it as the degree to which a TCP aggregate reduces its sending rate to the network as a response to packet drops. We define metrics that describe the responsiveness of TCP aggregates, and then we suggest two methods for determining the values of these quantities. The first method is based on a test in which we drop a few packets from the aggregate intentionally and measure the resulting rate decrease of that aggregate. This kind of test is not robust to multiple simultaneous tests performed at different routers. Extensions are done to make the test robust to multiple simultaneous tests by using ideas from the CDMA approach to multiple access channels in communication theory. Then we use these methods to perform congestion control. A distinguishing feature of our congestion control scheme is that it maintains a degree of fairness among different aggregates.