RE: China’s Slow Transnational Network

David Guo david at xtom.com
Tue Mar 3 08:30:44 UTC 2020


Hi Pengxiong,

The largest ISP in China, China Telecom offers 3 types of their IP Transit service

1. Normal China Telecom (AS4134), poor quality because of overselling their bandwidith.
2. CN2 GT (AS4809)
3. CN2 GIA (AS4809)

CN2 GT (Global Transit) is cheaper than CN2 GIA (Global Internet Access), CN2 GIA is the most expensive but with stable and best network quality.

Have you tested all of these 3 types? According to your pdf, only Alibaba Cloud in Hong Kong and Singapore has CN2 connectivity.

Another reason is the population of China, which is around 1.4 billion, and only 3 major ISPs (CT, CU and CM) can offer service to home users in China.

Regards,

David

From: NANOG <nanog-bounces at nanog.org> On Behalf Of Pengxiong Zhu
Sent: Tuesday, March 3, 2020 6:55 AM
To: Compton, Rich A <Rich.Compton at charter.com>
Cc: North American Network Operators' Group <nanog at nanog.org>; Zhiyun Qian <zhiyunq at cs.ucr.edu>
Subject: Re: China’s Slow Transnational Network

DDoS traffic is coming from China to the outside world, which should saturate the upstream link of China, however, what we observed is that the upstream link has high and stable performance, while the downstream link of China, which is traffic coming from the outside world to China, is suffering from slow speed.

Best,
Pengxiong Zhu
Department of Computer Science and Engineering
University of California, Riverside


On Mon, Mar 2, 2020 at 8:11 AM Compton, Rich A <Rich.Compton at charter.com<mailto:Rich.Compton at charter.com>> wrote:
My guess is that it’s all the DDoS traffic coming from China saturating the links.

From: NANOG Email List <nanog-bounces at nanog.org<mailto:nanog-bounces at nanog.org>> on behalf of Pengxiong Zhu <pzhu011 at ucr.edu<mailto:pzhu011 at ucr.edu>>
Date: Monday, March 2, 2020 at 8:58 AM
To: NANOG list <nanog at nanog.org<mailto:nanog at nanog.org>>
Cc: Zhiyun Qian <zhiyunq at cs.ucr.edu<mailto:zhiyunq at cs.ucr.edu>>
Subject: China’s Slow Transnational Network

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
The contents of this e-mail message and
any attachments are intended solely for the
addressee(s) and may contain confidential
and/or legally privileged information. If you
are not the intended recipient of this message
or if this message has been addressed to you
in error, please immediately alert the sender
by reply e-mail and then delete this message
and any attachments. If you are not the
intended recipient, you are notified that
any use, dissemination, distribution, copying,
or storage of this message or any attachment
is strictly prohibited.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.nanog.org/pipermail/nanog/attachments/20200303/c4b17723/attachment.html>


More information about the NANOG mailing list