Understanding the latency to visit websites in China: An infrastructure perspective

摘要

As the Internet becomes more and more widely used in our daily life, its latency has been regarded as a truly critical issue for various Internet applications. Researchers propose an ambitious goal to pursue "Speed-of-Light Internet. However, there is a large gap between the reality and the goal, and a lot of infrastructure inefficiency caused by simple issues has been observed in some developing or rural regions. In this article, we conduct a measurement study on the latency to visit more than 638 K websites in China from five well-connected vantage points, and examine the unnecessary latency caused by the inefficiency of DNS infrastructure and Internet routing infrastructure in China. We find that DNS resolution is the most significant contributor to the overall latency and investigate several important factors that affect DNS latency, i.e., caching, CNAME and delegation. In terms of Internet routing infrastructure in China, we observe that 1) the inter-domain routing in China relies too heavily on the three oldest IXPs while the newly deployed IXPs are under-used significantly, which results in unnecessary routing circuitousness; and 2) most congested links are the links connecting cities with IXPs and these links should be upgraded or utilized with more efficient traffic engineering systems. Furthermore, in order to compute circuitousness ratios and locate congested links, we also propose a method to geolocate IP addresses in China more accurately and we make the geolocation results for IP addresses under the study of this work publicly accessible to facilitate future research efforts. (C) 2020 Published by Elsevier B.V.