It’s the Government doing mandatory content filtering at the border. Their hardware is either deliberately or accidentally poor-performing.
I believe providing limited and throttled external connectivity may be deliberate; think of how that curtails for one thing; streaming video? -Ben. -Ben Cannon CEO 6x7 Networks & 6x7 Telecom, LLC b...@6by7.net <mailto:b...@6by7.net> > On Mar 1, 2020, at 9:00 PM, Pengxiong Zhu <pzhu...@ucr.edu> wrote: > > Hi all, > > We are a group of researchers at University of California, Riverside who have > been working on measuring the transnational network performance (and have > previously asked questions on the mailing list). Our work has now led to a > publication in Sigmetrics 2020 and we are eager to share some > interesting findings. > > We find China's transnational networks have extremely poor performance when > accessing foreign sites, where the throughput is often persistently > low (e.g., for the majority of the daytime). Compared to other countries we > measured including both developed and developing, China's transnational > network performance is among the worst (comparable and even worse than some > African countries). > > Measuring from more than 400 pairs of mainland China and foreign nodes over > more than 53 days, our result shows when data transferring from foreign nodes > to China, 79% of measured connections has throughput lower than the 1Mbps, > sometimes it is even much lower. The slow speed occurs only during certain > times and forms a diurnal pattern that resembles congestion (irrespective of > network protocol and content), please see the following figure. The diurnal > pattern is fairly stable, 80% to 95% of the transnational connections have a > less than 3 hours standard deviation of the slowdown hours each day over the > entire duration. However, the speed rises up from 1Mbps to 4Mbps in about > half an hour. > > > > We are able to confirm that high packet loss rates and delays are incurred in > the foreign-to-China direction only. Moreover, the end-to-end loss rate could > rise up to 40% during the slow period, with ~15% on average. > > There are a few things noteworthy regarding the phenomenon. First of all, all > traffic types are treated equally, HTTP(S), VPN, etc., which means it is > discriminating or differentiating any specific kinds of traffic. Second, we > found for 71% of connections, the bottleneck is located inside China (the > second hop after entering China or further), which means that it is mostly > unrelated to the transnational link itself (e.g., submarine cable). Yet we > never observed any such domestic traffic slowdowns within China. > Assuming this is due to congestion, it is unclear why the infrastructures > within China that handles transnational traffic is not even capable to handle > the capacity of transnational links, e.g., submarine cable, which maybe the > most expensive investment themselves. > > Here is the link to our paper: > https://www.cs.ucr.edu/~zhiyunq/pub/sigmetrics20_slowdown.pdf > <https://www.cs.ucr.edu/~zhiyunq/pub/sigmetrics20_slowdown.pdf> > > We appreciate any comments or feedback. > -- > > Best, > Pengxiong Zhu > Department of Computer Science and Engineering > University of California, Riverside
