This addresses the question of whether the PingER data can identify the impact of COVID-19 on the Internet. According to Most Internet Service Providers (ISPs) oversubscribe their bandwidth and networks as typical inbound and outbound traffic are bursty and often don’t sustain high levels on a continuous basis. Fortunately, most of the larger National Providers have had sufficient time to prepare for the impact of COVID-19 and plan for the possibility of business workloads shifting to the home. Regardless of this capacity planning, Internet traffic patterns are about to change drastically based on schools across the country opting for virtual learning and business work from home migrations. Also, Time Magazine April 5/ April 15, 2020, reports that "traffic worldwide is up 35%...Demand is highest in the evening in the past two weeks, says networking firm Century Link."

For example, one might expect that as schools shut, people self-isolate, are sent home from, work from home, lockdowns are imposed etc., physical person-to-person communications would migrate to the Internet and will increase the use of the Internet e.g. by virtual learning, streaming. communicating, gathering information and entertaining for example.  The thought is that this will lead to different Internet patterns and possibly lead to Internet congestion. A study of the impact of COVID-19 on Internet speeds by Ookla  ("TRACKING COVID-19’S IMPACT ON GLOBAL INTERNET PERFORMANCE") is directly relevant, however,  it is hard to identify any dramatic impact on the latencies in the report. There is also COVID-19 impacts on Internet traffic: Seattle, Northern Italy, and South Korea which looks at the impact on Internet traffic volumes. Also companies such as Netflix, Amazon, Apple, Disney, Google have reduced the quality of their videos to help reduce traffic and congestion of the Internet (see

PingER uses the ping facility to measure the Round Trip Time (RTT) between about 20 monitoring sites and target hosts in over 160 countries (over 10,000 pairs of monitor-remote(target_sites). Every 30 minutes the monitoring agent sends up to 30 pings at one-second intervals to each target until there are 10 responses, and records the data which are daily gathered, archived, analyzed and presented at the SLA C archiving site.


  • For Europe, US and Canada the Christmas/New Year season (end November thru 2nd week in January) may also be expected to change behaviors, so comparing with data before the first cases (Nov-Jan) may be tricky.
  • The measurements are from SLAC which shut down on March 17th, 2020, so the traffic on its links may have dramatically decreased after that.
  • Utilization across networks and services has changed dramatically in terms of volumes, number of connections, utilization of links, interfaces, service endpoints. Most services are scaling up to handle the load. There are also many outages due to misconfiguration as people are trying to configure with configurations in production.
  • The links from SLAC use the well-provisioned ESnet network and beyond that academic networks such as Internet2 in the US, GEANT in Europe, APAN in Asia, thus the measurements from SLAC may not be fully representative. 
  • Many of the targets are academic establishments that may have been closed, thus the target itself may be lightly loaded and so respond more quickly than in the past.

Milestones and Statistics

The milestones, for the virus itself, include 1st identified case, 1st hospitalization, 1st community case, 1st death.

Other milestones are the social impacts that are more likely to impact the internet traffic. These include social interventions:

  • Social distancing encouraged
  • Case-based measures
  • School and college closures
  • Public events banned
  • Lockdown
  • Interventions removed

See COVID 19 Internet Usage timeline for how companies have reduced their Internet traffic. Also see Akami sees 30 per cent surge in Internet traffic.


  • Number of days to double cases
  • Basic reproduction number R0 the average number of secondary infections produced by an infectious case where everyone is susceptible.
    • For R >1 each individual infected by a transmissible disease is expected to infect a number of individuals that increase exponentially. For R<1, each case transmits the disease to less than one individual and the disease dies out.
  • Control reproductive number RC, the value of R in the presence of control measures.
  • Incubation period
  • Risk of importation
  • Projections on: all beds needed, ICU beds needed, invasive ventilators needed.  
  • 20% daily growth = cases or deaths double in < 4 days


The PingER monitor at SLAC, Stanford University in California currently monitors about 100 hosts in China. Using the web page we selected daily aggregated data from SLAC to China for the last 365 days and looked at various metrics derived from the RTTs. Since many of the targets are Universities that may have taken lockdown measures and sent many students and staff home, we decided to look at the overall impact on SLAC to China pings. To do this we scroll down the page to summary tables as shown below.    

We can cut and paste this table into Excel to enable further analysis and visualization. Also the summary data is analyzed on a regular basis and the results made available as CSV files at The file names (e.g.average_rtt-EDU.SLAC.STANFORD.PINGER-continent-allmonthly.csv) provide the metric (average_rtt in example), the Monitoring Agent (EDU-SLAC.STANFORD.PINGER in example), the region (continent or country) and the time window of each data point (or Tick, e.g. monthly (=last 12 months), allmonthly, or allyearly).

Using Motion Charts to look at PingER data by metric versus Covid cases

Examining using PingER metrics from

Impact by region

China and North America

Looking at the plot of daily average RTTs there is a peak  (going from 145ms to 160ms) in minimum (average RTT) from Jan 10 to Jan 24th 2020, plus another spike on Feb 19.

A similar result is seen for the daily minimum RTTs.

 Currently I do not know why we see these bumps or what they are telling us.

Looking at the Inter Packet Delay Variation (IPDV, ) a measure of the variability between adjacent ping packet RTTs there is some evidence that the variability reduced between 18th Jan and March 10th 2020.  The first person in China to die of the COVID-19 virus was reported on January 10th, and by January 31st there were 9,720 cases in China. Looking in more detail at the Healthmap one sees

Looking in more detail at the Healthmap one sees the dramatic spread of the virus in China between January 13 and January 20, 2020. Thus the drop in IPDV RTTs may indeed be linked to the impact of the growth of COVID-19 infections in China.

January 13, 2020January 20, 2020

 I can see nothing similar when looking at the US and Canada (N. America) IPDV  data, maybe the effect is later in the evolution of the virus' impact. 

Aggregating the IPDV data monthly for China we see the following where we show the median together with the 25% and 75% going back to September 2017:


Looking at the percent packet loss for China there may be some evidence for a change in the 75%. Thus the impact is seen for a few sites. However, the climb started in August-September 2019 so it is doubtful it is related to COVID-19. This conclusion is confirmed by looking at the monthly aggregates.

For the US and Canada the losses are lower and usually 0% (typically >=90% of the targets show no losses), so instead we show the average maximum losses

PingER monitors two hosts in Hubei: at Hubei University for Nationalities and Hubei University of Automotive Technology and at the Hubei University of Automotive Technology. The locations of the two Universities is shown below.

The hourly measurements for and are shown below (one can use the form to create such a plot).



In general there are marked diurnal changes. There is a slight increase in RTTs following the Chinese New Year January 25th 2020. Then there is a small step reduction in RTTs March 10, 2020, followed by an increase in the packet losses starting March 18th 2020.

PingER average hourly RTT from SLAC to Hubei University for NationalitiesPingER percent hourly packet loss from SLAC to Hubei University for Nationalities

If we look at the daily aggregates for the packet loss per cent, average RTT and Inter Packet Delay Variation and from 3/23/2019 thru 3/21/2020  and then expand to see the subset from 1/1/2020 thru 3/21/2020 we get the plots below. 



Note that www.

It is clear that there are huge variations in the measurements over the last year. Looking at just 2020 data there does appear to be evidence for an almost factor of 2 change in the IPDVs towards the end of January, in opposite directions for the two hosts. N.b we might expect to see something following the January 23rd lockdown of the Wuhan region. There is a "flutter" in the IPDV around that time, whether it is related to the shutdown is unclear.

Looking at the aggregated monthly IPDVs for the two hosts we see:



Italy jumped from three incidents on Friday, February 21 to 229 by the time of WHO’s February 25 situation report

For Italy, PingER monitors 7 hosts. They are in Bologna, Udine, Rome, Pisa and Frascati. These are not the hardest hit areas (see here).

After removing one ( which stopped responding on February 20, 2020 the IPDV for each of the Italian hosts appears as below:

There appears to be a dramatic drop in the IPDV for the target host in Bologna between the end of January and Feb 19th. Italy's first COVID-19 case was announced February 19th, thus it is doubtful this drop has anything to do with COVID-19.

A lockdown began for Northern Italy on March 8th and extended to all Italy on March 9th. A plot of the daily IPDV measured from SLAC to 6 Italian hosts together with some COVID-19 milestones is shown below. The milestones are 17 cases diagnosed Feb 21 (including first local transmissions) and 225(105 new) Feb 25. The progress of COVID-16 in Italy can be seen here. There are 6 Italian hosts being monitored from SLAC the values shown are the 25%, median and 75% of the daily IPDV measured for the 6 hosts for the given days.


There are 4 hosts in Spain monitored by SLAC and are in Madrid, is in Elda in the province of Alicante in Eastern Spain, and 

For  Spain:


  • Self isolation was mandated March 17
  • Social distancing was encouraged March 9
  • Public events were banned March 14
  • School closure was ordered March 13
  • Lockdown was ordered March 14.

More Information.


Potential Long-term Intervention Strategies for COVID-19 

Probably the best source of PingER data is which is aggregated data for various metrics by region and time window (or tick).

Unacast uses cell phone location data to get a measure of how people are social distancing.

Johns Hopkins University data on Covid-19 cases etc,

Wikipedia has a graphical timeline by country.

Timeline for Covid-19 Interventions by country.

Timeline of Covid-19

How Severe Are Coronavirus Outbreaks Across the U.S.? Look Up Any Metro Area, from the New York Times

Impact of Covid-19 on Internet traffic:

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