Tackling the latency divide with Copa

Abstract

As voice- and video-based services that require low latency become increasingly essential, a tremendous research effort has been devoted to improving the latency performance of networks. However, there remains a "latency divide" between those whose Internet access is subject to high latency and those with low-latency access. Furthermore, it is unclear whether the aforementioned research efforts narrow this divide (by improving the latency performance of poor-quality connections the most), maintain the divide (by improving poor- and high-quality connections equally), or even widen the divide (by mostly reducing latency of high-quality network connections). In this work, we design a reproducible experiment for evaluating the performance of Copa, a delay-based congestion control protocol, in different categories of residential broadband connections. We use empirical data from U.S. home network connections to evaluate whether Copa leads to more equitable network access. We confirm that Copa has potential to narrow the "digital divide" by improving latency performance for users with a low-quality residential broadband connection, although care must be taken to set appropriate parameters for best performance.