Re: China’s Slow Transnational Network

[Matt Corallo <nanog () as397444 net>]

It also gives local competitors a leg up by helping domestic apps perform better simply by being hosted domestically 
(or making foreign players host inside China).

> On Mar 2, 2020, at 11:27, Ben Cannon <ben () 6by7 net> wrote:
>
> 
> 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 
> ben () 6by7 net
>
>
>
>
> > On Mar 1, 2020, at 9:00 PM, Pengxiong Zhu <pzhu011 () 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
> >
> > We appreciate any comments or feedback. 
> > -- 
> >
> > Best,
> > Pengxiong Zhu
> > Department of Computer Science and Engineering
> > University of California, Riverside