Re: China’s Slow Transnational Network

[Matt Corallo <nanog () as397444 net>]

> find out direct evidence of mandatory content filtering at the border

You seem to be implying that you don't believe/can't see the GFW, which
seems surprising. I've personally had issues with traffic crossing it
getting RST'd (luckily I was fortunate enough to cross through a GFW
instance which was easy to avoid with a simple iptables DROP), but its
also one of the most well-studied bits of opaque internet censorship
gear in the world. I'm not sure how you could possibly miss it.

Matt

On 3/2/20 2:55 PM, Pengxiong Zhu wrote:
> Yes, we agree. The poor transnational Internet performance effectively
> puts any foreign business that does not have a physical presence (i.e.,
> servers) in China at a disadvantage.
> The challenge is to find out direct evidence to prove mandatory content
> filtering at the border, if the government is actually doing it.
>
> Best,
> Pengxiong Zhu
> Department of Computer Science and Engineering
> University of California, Riverside
>
>
> On Mon, Mar 2, 2020 at 8:38 AM Matt Corallo <nanog () as397444 net
> <mailto:nanog () as397444 net>> wrote:
>
>     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
> >     <mailto: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 <mailto:ben () 6by7 net>
> >
> >
> >
> > >     On Mar 1, 2020, at 9:00 PM, Pengxiong Zhu <pzhu011 () ucr edu
> > >     <mailto: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