TCP-friendly Congestion Control for Real-time Streaming Applications
Deepak Bansal, Hari Balakrishnan · DSpace@MIT (Massachusetts Institute of Technology) · 2000
This paper introduces and analyzes a class of nonlinear congestion control algorithms called binomial algorithms, motivated in part by the needs of streaming audio and video applications for which a drastic reduction in transmission rate upon congestion is problematic. Binomial algorithms generalize TCP-style additive-increase by increasing inversely proportional to a power # of the current window (for TCP, # ##) ; they generalize TCP-style multiplicative-decrease by decreasing proportional to a power # of the current window (for TCP, # # #). We show that there are an infinite number of deployable TCP-friendly binomial algorithms, all of which satisfy # # # ##, and that all binomial algorithms converge to fairness under a synchronized-feedback assumption provided # # # # ## ## # #. Our simulation results show that binomial algorithms interact well with TCP across a RED gateway. We focus on two particular algorithms, IIAD (inverse-increase/additive-decrease, # ######) and SQRT (# # # # ###), showing that they are well-suited to applications that do not react well to large TCP-style window reductions. We also find that TCP-friendliness in terms of the relationship between throughput and loss rate of an algorithm does not necessarily imply fairness relative to TCP performance, especially for drop-tail bottleneck gateways.