Report from the IAB COVID-19 Network Impacts Workshop 2020
draft-iab-covid19-workshop-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 9075.
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|---|---|---|---|
| Authors | Jari Arkko , Stephen Farrell , Mirja Kühlewind , Colin Perkins | ||
| Last updated | 2021-02-01 | ||
| RFC stream | Internet Architecture Board (IAB) | ||
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draft-iab-covid19-workshop-00
Network Working Group J. Arkko
Internet-Draft Ericsson
Intended status: Best Current Practice S. Farrell
Expires: 5 August 2021 Trinity College Dublin
M. Kühlewind
Ericsson
C. Perkins
University of Glasgow
1 February 2021
Report from the IAB COVID-19 Network Impacts Workshop 2020
draft-iab-covid19-workshop-00
Abstract
The COVID-19 pandemic caused changes in Internet traffic,
particularly during the introduction of the initial quarantine and
work-from-home arrangements.
The Internet Architecture Board (IAB) held a workshop to discuss
Network Impacts of the pandemic, on November 9-13, 2020. The
workshop was held to convene interested researchers, network
operators, and network management experts, and Internet technologists
to share their experiences. The meeting was held online given the
on-going travel and contact restrictions at that time.
Discussion Venues
This note is to be removed before publishing as an RFC.
Source for this draft and an issue tracker can be found at
https://github.com/intarchboard/covid19-workshop.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on 5 August 2021.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Workshop Topics and Discussion . . . . . . . . . . . . . . . 4
3.1. Measurement-based Observations on Network Traffic
Dynamics . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.1. Overall Traffic Growth . . . . . . . . . . . . . . . 5
3.1.2. Changes in Application Use . . . . . . . . . . . . . 6
3.1.3. Mobile Networks and Mobility . . . . . . . . . . . . 8
3.1.4. A Deeper Look at Interconnections . . . . . . . . . . 9
3.1.5. Cloud Platforms . . . . . . . . . . . . . . . . . . . 9
3.1.6. Last Mile Congestion . . . . . . . . . . . . . . . . 10
3.1.7. User Behaviour . . . . . . . . . . . . . . . . . . . 10
3.2. Operational Practises and Architectural Considerations . 11
3.2.1. Digital Divide . . . . . . . . . . . . . . . . . . . 11
3.2.2. Applications . . . . . . . . . . . . . . . . . . . . 12
3.2.3. Observability . . . . . . . . . . . . . . . . . . . . 13
3.2.4. Security . . . . . . . . . . . . . . . . . . . . . . 14
3.2.5. Discussion . . . . . . . . . . . . . . . . . . . . . 14
3.3. Conclusions . . . . . . . . . . . . . . . . . . . . . . . 15
4. Feedback on Meeting Format . . . . . . . . . . . . . . . . . 16
5. Position Papers . . . . . . . . . . . . . . . . . . . . . . . 16
6. Workshop participants . . . . . . . . . . . . . . . . . . . . 17
7. Program Committee . . . . . . . . . . . . . . . . . . . . . . 19
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20
9. Informative References . . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
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1. Introduction
The Internet Architecture Board (IAB) held a workshop to discuss
Network Impacts of the COVID-19 pandemic, on November 9-13, 2020.
The workshop was held to convene interested researchers, network
operators, and network management experts, and Internet technologists
to share their experiences. The meeting was held online given the
on-going travel and contact restrictions at that time.
COVID-19 has caused changes in Internet traffic. These changes
appeared rather abruptly and were significant, in particular during
the introduction of the initial quarantine and work-from-home
arrangements. The changes relate to traffic volumes, location of
traffic, as well as the types of traffic and applications used.
Announcement for the workshop was sent out in July 2020, requesting
interested parties to submit position papers for the workshop program
committee. A total of 15 position papers were received from
altogether 33 authors. The papers are listed in Section 5. In
addition, several other types of contributions and pointers to
existing work were provided. A number of position papers referred to
parallel work being published in measurement-related academic
conferences.
Invitations for the workshop were sent out based on the position
papers and other expressions of interest. On the workshop conference
calls were 45 participants, listed in Section 6.
The workshop was held over one week hosting three sessions covering
i) measurements and observations, ii) operational issue, and iii)
final future consideration and conclusions. As these three sessions
were scheduled Monday, Wednesday, and Friday a positive side effect
was that the time in between could be used for mailing list
discussion and compilation of additional workshop material.
2. Scope
The COVID-19 pandemic has had a tremendous impact on people's lives
and the societies and economies around the globe. But it also had
big impact on networking. With large numbers of people working from
home or otherwise depending on the network for their daily lives,
network traffic volume has surged. Internet service providers and
operators have reported a 20% traffic growth or more in a matter of
weeks. Traffic in Internet Exchange Points (IXPs) is similarly on
the rise. Most forms of network traffic have seen an increase, with
conversational multimedia traffic growing in some cases more than
200%. And user time spent on conferencing services has risen by an
order of magnitude on some conferencing platforms.
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In general, the Internet has coped relatively well with this traffic
growth, albeit not without some issues. For instance, some outages,
video quality reduction, and other issues were reported.
Nevertheless, it is interesting to see how the technology, operators
and service providers have been able to respond to large and sudden
changes in traffic patterns.
Understanding what actually happened with Internet traffic is of
course interesting by its own right. How that impacted user
experience, or the intended function of the services is equally
interesting. Measurements and reports of the traffic situation from
2020 are therefore valuable. But it would also be interesting to
understand what types of network management and capacity expansion
actions were taken in general. Anecdotal evidence points to Internet
and service providers tracking how their services are used, and in
many cases adjusting services to accommodate the new traffic
patterns, from dynamic allocation of compute resources to more
complex changes.
The impacts of this crisis are also a potential opportunity to
understand the impact of traffic shifts and growth more generally, or
to prepare for future situations -- crisis or otherwise - that impact
networking. Or even allow us to adjust the technology to be even
better suited to respond to changes.
The scope of this workshop included:
* measurements about traffic changes, user experience, service
performance, and other relevant aspects
* discussion about the behind the scenes network management and
expansion activities
* experiences in the fields of general Internet connectivity,
conferencing, media/entertainment, and Internet infrastructure
* lessons learned for preparedness and operations
* lessons learned for Internet technology and architecture
3. Workshop Topics and Discussion
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3.1. Measurement-based Observations on Network Traffic Dynamics
The workshop started with a focus on measurements. A large portion
of the submitted papers presented and discussed measurement data and
these submissions provided a good basis get a better understanding of
the situation, covering different angles and aspects of network
traffic and kind of networks.
Changes in Internet traffic due to the COVID-19 pandemic are
affecting different networks in various ways. Yet all networks
observe some form of change, be it in a reduction in traffic, an
increase in traffic, a change in working days and weekend days
patterns, or a change in traffic classes. Traffic volume,
directionality ratios, and its source and destination are radically
different from before COVID-19.
At a high level, while traffic from home networks increased
signficiantly, the traffic in mobile networks decreased as a result
of reduced population mobility. Further, there was a strong increase
in video conferencing and remote learning application traffic due to
the shift for working and learning at home. With that swift, the
typical diurnal usage patterns in network traffic also changed, with
peak times occuring earlier in the day and peak times lasting longer
over the day - reflecting the start of the work or school day from
home. This behavior is antagonistic, yet complementary, to the one
observed in residential ISPs.
While diurnal congestion at interconnect point sas well in certain
last mile network was reported, mainly in March, but no persitent
congestion was observed. Further a downward trends in download
throughput to certain cloud regions was measured which can probably
explained with the increase use of clould services, giving another
indication that the scalng of shared resources in the Internet in
working resonably well to even handle larger changes in traffic as
experience during the first nearly global lockdown of the COVID-19
pandemic.
3.1.1. Overall Traffic Growth
The global pandemic has significantly accelerated the growth of data
traffic worldwide. Based on the measurement data of one ISP, three
IXPs, a metropolitan educational network, and a mobile operator it
was observed at the beginning of the workshop [Feldmann2020] that
overall the network was able to handle the situation well despite a
significant and sudden increase in traffic growth rate in March/
April. That is, after the lockdown is implemented in March a traffic
increase of 15-20% at the ISP as well as the three IXPs was observed.
That represents the traffic growth expected in a typical year which
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now took place in the matter of a few weeks only---a substantial
increase. At DE-CIX Frankfurt, the world's largest Internet Exchange
in terms of data throughput, the year 2020 has seen the largest
increase in peak traffic within a single year since the IXP was
founded in 1995. Additionally, mobile traffic is slightly receding.
In access networks, the growth rate of upstream traffic also exceeded
the growth in downstream traffic, reflecting increased adoption and
use of video conferencing and other remote work and school
applications.
Most traffic increases happen during non-traditional peak hours:
Before the first COVID-19 lockdowns, the main time of use was in the
evening hours during the week, whereas since March it has been spread
equally across the day. That is, the increase in usage is mainly
occurring outside the previous peak usage times (e.g. during the day
while working from home). This means that, for the first time,
network utilization on weekdays resembles that on weekends. The
effects of the increased traffic volume can easily be absorbed:
either by using existing reserve capacity, or by quickly switching
additional bandwidth. This is one reason why the Internet was able
to cope well with the pandemic during the first lockdown period.
Some of the lockdowns were lifted or relaxed around May 2020. As
people were allowed to perform some of their daily habits outside of
their home again, as expected, there was a decrease of the traffic at
the IXPs and the ISP observed; instead mobile traffic is now growing
again.
3.1.2. Changes in Application Use
The composition of data traffic has changed since the beginning of
the pandemic: the use of videoconferencing services and virtual
private networks (VPNs) for access to company resources from the home
environment has risen sharply. In ISP and IXP network it was
overserved [Feldmann2020] that traffic associated to web
conferencing, video, and gaming increased largely in March 2020 as a
result of the increasing user deman for solutions like Zoom or
Microsoft Teams could be observed. For example, the relative traffic
share of many "essential" applications like VPN and conferencing
tools increased by more than 200%. Also, as people spend more hours
at home, they tend to watch videos or play games, thus increasing
entertainment traffic demands. At the same time, the traffic share
for other traffic classes decreases substantially, e.g., traffic
related to education, social media, and---for some periods---CDNs.
In April and June, web conferencing traffic is still high compared to
the pre-pandemic scenario, while a slight decrease in CDN and social
media traffic is observed. During these months many people are still
working from home, but restrictions have been lifted or relaxed,
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which likely leads to an increase in in-person social activities and
a decrease in online ones.
3.1.2.1. Example Campus Networks
Changes in traffic have been observed at University campus networks
as well, especially due to the necessary adoption of remote teaching.
The Politecnico di Torino University (Italy) deployed its in-house
solution for remote teaching, which caused the outgoing traffic to
grow by 2.5 times, driven by more than 600 daily online classes.
Incoming traffic, instead, decreased by a factor of 10 due to the
cessation of any in-presence activity. Based on their measurements,
this change in traffic and network usage did however not lead to
noticeable performance impairments, nor significantly poor
performance have been observed for students in remote regions of
Italy. Further, outgoing traffic increased as well due to remote
working solutions such as collaboration platforms, VPNs and remote
desktop.
Similar changes were observed by measuring REDIMadrid [Feldmann2020],
a European educational and research network, which connects 16
independent universities and research centers in the metropolitan
region of Madrid. A drop of up to 55% in traffic volume on working
days during the pandemic was observed. Similar to findings for ISP/
IXP networks, it was observed that working days and weekend days are
becoming more similar in terms of total traffic. The hourly traffic
patterns reveal a traffic increase between 9 pm and 7 am. This could
be due to users working more frequently at unusual times, but also
potentially caused by overseas students (mainly from Latin America
and East Asia as suggested by the AS numbers from which these
connections come from) who access university network resources from
their home countries.
Given the fact that the users of the academic network (e.g., students
and research staff) had to leave the campus as a response to lockdown
measures, also the traffic in/out (i.e., ingress/egress) ratio
changed drastically. Prior to the lockdown, the incoming traffic was
much larger then the outgoing traffic. This changed to a more
balanced setting. This change of traffic asymmetry can be explained
by the nature of remote work. On the one end, users connect to the
network services mainly to access resources, hence the increase in
outgoing traffic. On the other end, all external (i.e., Internet-
based) resources requested during work are no longer accessed from
the educational network but from the use
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3.1.3. Mobile Networks and Mobility
Mobile network data usage appeared to decline following the
imposition of localized lockdown measures, as these reduced typical
levels of mobility and roaming.
[Lutu2020] measured the cellular network of O2 UK to evaluate how the
changes in people's mobility impacted traffic patterns. By analyzing
cellular network signalling information regarding users' device
mobility activity, they observed a decrease of 50% in mobility
(according to different mobility metrics) in the UK during the
lockdown period. As they founnd no correlation between this
reduction in mobility and the number of confirmed COVID-19 cases,
only the enforced government order was effective in significantly
reducing mobility and this reduction was more significant in densely
populated urban areas than in rural areas. For London, specifically,
it could be observed from the mobile network data that approximately
10% of the residents temporarily relocated during the lockdown.
These mobility changes have immediate implications in traffic
patterns of the cellular network. The downlink data traffic volume
aggregated for all bearers (including conversational voice) decreased
for all UK by up to 25% during the lockdown period. This correlates
with the reduction in mobility that was observed country-wide, which
results in people likely relying more on the broadband residential
Internet access to run download intensive applications such as video
streaming. The observed decrease in the radio cell load, with a
reduction of approximately 15% across the UK after the stay-at-home
order, further corroborates the drop in cellular connectivity usage.
The total uplink data traffic volume, on the other hand, experienced
little changes (between -7% and +1,5%) during lockdown. This is
mainly due to the increase of 4G voice traffic (i.e., VoLTE) across
the UK that peaked at 150% after lockdown compared to the national
medial value before the pandemic, thus compensating the decrease in
data traffic in the uplink.
Finally, it was also observd that mobility changes have different
impact on network usage in geodemographic area clusters. In densely
populated urban areas, a significantly higher decrease of mobile
network usage (i.e., downlink and uplink traffic volumes, radio load
and active users) was observed than in rural areas. By looking into
the case of London, this is likely due to geodemographics of the
central districts, which include many seasonal residents (e.g.,
tourists), business and commercial areas.
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3.1.4. A Deeper Look at Interconnections
Traffic at points of network interconnection noticeably increased but
most operators reacted quickly by rapidly adding additional capacity
[Feldmann2020]. The amount of increases varied, with some networks
that hosted popular applications such as video conferencing
experiencing traffic growth of several hundred to several thousand
percent. At the IXP-level, it was observe that port utilization
increases. This phenomenon is mostly explained by a higher traffic
demand from residential users.
Measurements of interconnection links at major US ISPs by CAIDA and
MIT found some evidence of diurnal congestion around the March 2020
timeframe [Clark2020], but most of this congestion disappeared in a
few weeks, which suggests that operators indeed did take steps to add
capacity or otherwise mitigate the congestion.
3.1.5. Cloud Platforms
Cloud infrastructure played a key role in supporting bandwidth-
intensive video conferencing and remote learning tools to practice
social distancing in COVID-19 pandemic. Network congestion between
cloud platforms and access networks could impact on the quality of
experience of these cloud-based applications. CAIDA leveraged web-
based speed test servers to perform download and upload throughput
measurements from virtual machines in public cloud platforms to
various access ISPs in the United States [Mok2020].
The key findings included:
* Persistent congestion events were not widely observed between
cloud platforms and these networks, particular for large-scale
ISPs, but we could observe large diurnal download throughput
variations in peak hours from some locations to the cloud.
* There is evidence of persistent congestion in the egress direction
to regional ISPs serving suburban areas in the U.S. Their users
could suffer from poor video streaming or file download
performance from the cloud.
* The macroscopic analysis over 3 months (June-August, 2020)
revealed downward trends in download throughput from ISPs and
educational networks to certain cloud regions. We believed that
increased use of the cloud in the pandemic could be one of the
factors that contributed to the decreased performance.
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3.1.6. Last Mile Congestion
Last-mile is the centerpiece of broadband connectivity, where poor
last-mile performance generally translates to poor quality of
experience. In a recent IMC'20 research paper Fontugne et al.
investigated last-mile latency using traceroute data from RIPE Atlas
probes located in 646 ASes and looked for recurrent performance
degradation [Fontugne2020-1]. They found that in normal times Atlas
probes in only 10% ASes experience persistent last-mile congestion
but they recorded 55% more congested ASes during the COVID-19
outbreak. This deterioration caused by stay-at-home measures is
particularly marked in large eyeball networks and certain parts of
the world. They found Japan to be the most impacted country in their
study looking specifically at NTT OCN, but noting similar
observations for several Japanese networks, including IIJ (AS2497).
From mid-2020 onwards, they however observe better performance than
before the pandemic. In Japan, this is partly due to the deployments
originally planned for accommodating the Tokyo Olympics, and more
generally, it reflects the efforts of network operators to cope with
these exceptional circumstances. The pandemic has demonstrated that
its adaptive design and proficient community can keep the Internet
operational during such unprecedented events. Also, from the
numerous research and operational reports recently published, the
pandemic is apparently shaping a more resilient Internet, as
Nietzsche wrote, "What does not kill me makes me stronger".
3.1.7. User Behaviour
The type of traffic needed by the users also changed in 2020.
Upstream traffic increased due the use of video conferences, remote
schooling, and similar applications. The NCTA and Comcast reported
that while downstream traffic grew 20%, upstream traffic grew as much
as 30% to 37% [NCTA2020] [Comcast2020]. Vodafone reported that
upstream traffic grew 100% in some markets [Vodafone2020].
Ericsson's Consumer Lab surveyed users for their usage and
experiences during the crisis). Some of the key findings in
[ConsumerlabReport2020] were:
* 9 in 10 users increased Internet activities, and time spent
connected increased. In addition, 1 in 5 started new online
activities, many in the older generation felt that they were
helped by video calling, parents felt that their children's
education was helped, and so on.
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* Network performance was in general found satisfactory. 6 in 10
were very satisfied with fixed broadband, and 3 in 4 felt that
mobile broadband was the same or better compared to before the
crisis. Consumers valued resilience and quality of service as the
most important task for network operators.
* Smartphone application usage changed, with fastest growth in
COVID-19, remote working, e-learning, wellness, education, remote
health consultation, and social shared experience applications.
Biggest decreases were in travel and booking, ride hailing,
location, and parking applications.
Some of the behaviours are likely permanent changes
[ConsumerlabReport2020]. The adoption of video calls and other new
services by many consumers, such as the older generation, is likely
going to have a long-lasting effect. Surveys in various
organizations point to a likely long-term increase in the number of
people interested in remote work [WorkplaceAnalytics2020]
[McKinsey2020].
3.2. Operational Practises and Architectural Considerations
The second and third day of the workshop were held based on more open
discussions focussed on operational issues and the architectural
issues arising or other conclusions that could be reached.
3.2.1. Digital Divide
Measurements from Fastly confirmed that Internet traffic volume, in
multiple countries, rose rapidly at the same time as COVID cases
increased and lock down policies came into effect. Download speeds
also decreased, but in a much less dramatic fashion than overall
bandwidth usage increased. School closures led to a dramatic
increase in traffic volume in many regions, and other public policy
announcements triggered large traffic shifts. This suggests that
governments might usefully coordinate with operators to allow time
for pre-emptive operational changes, in some cases.
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Measurements from the US showed that download rates correlate with
income levels. However, download rates in the lowest income zip
codes increased as the pandemic progressed, closing the divide with
higher income areas. One possible reason for this in the data is
decisions by some ISPs, such as Comcast and Cox, that increased
speeds for users on certain plans and in certain areas. This
suggests that network capacity was available, and that the
correlation between income and download rates was not necessarily due
to differences in the deployed infrastructure in different regions,
although it was noted that certainly access link technologies provide
more flexibility than others in this regard.
3.2.2. Applications
The web conferencing systems (e.g., Microsoft Teams, Zoom, Webex) saw
incredible growth, with overnight traffic increases of 15-20% in
response to public policy changes, such as lock downs. This required
significant and rapid changes in infrastructure provisioning.
Major video providers (YouTube, etc.) reduced bandwidth by 25% in
some regions. It was suggested that this had a huge impact on
quality of videoconferencing systems until networks could scale to
handle full bit-rate, but other operators of some other services saw
limited impact.
Updates to popular games has a significant impact on network load.
Some discussions were reported between ISPs, CDNs, and the gaming
industry on possibly coordinating various high-bandwidth update
events, similar to what was done for entertainment/video download
speeds. There was an apparently difficult interplay between bulk
download and interactive real-time applications, potentially due to
buffer-bloat and queuing delays.
It was noted that operators have experience of rapid growth of
Internet traffic. New applications with exponential growth are not
that unusual in the network, and the traffic spike due to the lock
down was not that unprecedented for many. Many operators have tools
and mechanisms to deal with this. Ensuring that knowledge if shared
is a challenge.
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Following these observations traffic prioritisation was discussed,
starting from DSCP marking, basically wondering if a minimal priority
marking scheme would have helped during the pandemic, e.g. by
allowing marking of less-than-best-effort traffic. That discussion
quickly deolved into a more general QoS and observability discussion,
and as such also touching on the effects of increased encryption.
The group was not, unsuprisingly, able to finally resolve the
different perspectives and interests involved in that, but the
discussion demonstrated that progress is made (and being less
heated).
3.2.3. Observability
It is clear that there is a contrast in experience. Many operators
reported few problems, in terms of metrics such as measured download
bandwidth, while video conferencing applications experienced
significant usability problems running on those networks. The
interaction between application providers and network providers
worked very smoothly to resolve these issues, supported by strong
personal contacts and relationships. But it seems clear that the
metrics used by many operators to understand their network
performance don't fully capture the impact on certain applications,
and there is an observability gap. Do we need more tools to figure
out the various impacts on user experience?
These types of applications use surprising amounts of FEC.
Applications hide lots of loss to ensure a good user experience.
This makes it harder to observe problems. The network can be
behaving poorly, but experience can be good enough. Resiliency
measures can improve the user experience but hide severe problems.
There may be a missing feedback loop between application developers
and operators.
It's clear that it's difficult for application providers and
operators to isolate problems. Is a problem due to the local WiFi,
the access network, cloud network, etc. Metrics from access points
would help, but in general lack of observability into the network as
a whole is a real concern when it comes to debugging performance
issues.
Further, it's clear that it can be difficult to route problem reports
to the person who can fix them, across multiple networks in the
Internet. COVID enhanced cooperation, making it easier to debug
problems; lines of communication are important.
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3.2.4. Security
It was noted that there is a shift to home working generally, and in
the way people use the network, with IT departments rolling out new
equipment quickly and using technologies like VPNs for the first
time.
There are reports of a strong rise in phishing, fraud, and scams
related to COVID [Kirsty2020]. It's unclear if there was an increase
in fraud overall but there was certainly a shift in activity. New
types of attacks, for example on vaccine research labs, health
services, and home working were reported.
It's unclear how to effectively detect and counter these attacks at
scale. Approaches such as crowd-sourced flagging of suspicious
emails help, and others noted that observing DNS to detect malicious
use is popular. The use of DNS over HTTPS offers privacy benefits
but is also observed to bypasses some protective measures.
It was also noted that when everyone moves to performing their job
online, lack of understanding of security becomes a bigger issue.
Who is ultimately responsible for security? Do we expect every user
of the Internet to take password training? Or is there a fundamental
problem here with a technical solution. Technologies such as Zoom
are not new: many people have used then for years; nobody attacked it
until it was the front line. What's the next vulnerable service?
Overall, it may be that the pandemic caused fewer security changes,
with many people suddendly work from home, than one would have
guessed pre-pandemic. However, existing security problems and
challenges may have become even more obvious and acute with an
increased use of Internet-based services.
3.2.5. Discussion
There is a concern that we're missing observability for the network
as a whole. Each application provider and operator has its our own
little lens. No-one has the big-picture view of the network.
How much of a safety margin do we need? Some of the resiliency comes
from us not running the network too close to its limit. This allows
traffic to shift, and gives headroom for the network to cope. The
best effort nature of the network may help here. Techniques to run
the network closer to its limits improve performance in the usual
case, but highly optimised networks may be less robust.
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Finally, it was observed that we get what we measure. There may be
an argument for operators to shift their measurement focus perhaps
away from pure capacity, to rather measure QoE or resilience. The
Internet is critical infrastructure, and people are realising that
now. We should use this as a wake-up-call to improve resilience,
both in protocol design and operational practise, not necessarily to
optimise for absolute performance or quality of experience.
3.3. Conclusions
There is a wealth of data about the performance of the Internet
during the crisis. The main conclusion from the various measurements
is that fairly large shifts occurred. And those shifts were not
merely about changing one application for another, they actually
impacted traffic flows and directions, and caused in many cases a
significant traffic increase. Early reports also seem to indicate
that the shifts have gone relatively smooth from the point of view
overall consumer experience.
An important but not so visible factor that led to this was that many
people and organizations where highly motivated to ensure good
experience. A lot of collaboration happened in the background,
problems were corrected, many providers significantly increased their
capacity, and so on.
In general, the Internet also seems well suited for adapting to new
situations, at least within some bounds. The Internet is designed
for any application and situation, rather than optimized for today's
particular traffic. This makes it possible to use it for many
applications, in many deployment situations, and make changes as
needed. The generality is present in many parts of the overall
system, from basic Internet technology to browsers, from name servers
to content delivery networks and cloud platforms. When needs change,
what is needed is often merely different services, perhaps some re-
allocation of resources, but not fundamental technology or hardware
changes.
On the other hand, this is not to say that no improvements are
needed:
* Better understanding of the health of the Internet: Going forward,
the critical nature that Internet plays in our lives means that
the health of the Internet needs to receive significant attention.
Understanding how well networks work is not just a technical
matter, it is also of crucial importance to the people and economy
of the societies using it. Projects and research that monitor
Internet and services performance in a broad scale and across
different networks are therefore important.
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* The pandemic has shown how the effects of the digital divide can
be amplified during a crisis. More attention is needed to ensure
that broadband is available to all, and that Internet services
equally serve different groups.
* We need to continue work on all the other improvements that are
seen as necessary anyway, such as further improvements in
security, ability for networks and applications to collaborate
better, etc.
* Informal collaboration between different parties needs to continue
and be strengthened.
4. Feedback on Meeting Format
While there are frequently virtual participants in IAB workshops, the
IAB had no experience running workshops entirely virtually.
Feedback on this event format was largely positive, however. It was
particularly useful that as the three sessions were scheduled Monday,
Wednesday, and Friday, the time in between could be used for mailing
list discussion and compilation of additional workshop material. The
positive feedback was likely at least partly due to the fact that
many of the workshop participants knew one another from previous
face-to-face events (primaily IETF meetings).
The process for sending invitations to the workshop should be
improved for next time, however, as a few invitations were initially
lost, and in a virtual meeting it may be more reasonable to invite
not just one person but co-authors of a paper, for instance. At
least for this workshop, we did not appear to suffer from too many
participants, and in many cases there may be some days when a
particular participant may not be able to attend a session.
5. Position Papers
The following position papers were received, in alphabetical order:
* Afxanasyev, A., Wang, L., Yeh, E., Zhang, B., and Zhang, L.:
Identifying the Disease from the Symptoms: Lessons for Networking
in the COVID-19 Era [Afxanasyev2020]
* Arkko, Jari: Observations on Network User Behaviour During
COVID-19 [Arkko2020]
* Bronzino, F., Culley, E., Feamster, N. Liu. S., Livingood. J.,
and Schmitt, P.: IAB COVID-19 Workshop: Interconnection Changes in
the United States [Bronzino2020]
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* Campling, Andrew and Lazanski, Dominique: Will the Internet Still
Be Resilient During the Next Black Swan Event? [Campling2020]
* Cho, Kenjiro: On the COVID-19 Impact to broadband traffic in Japan
[Cho2020]
* Clark, D.: Measurement of congestion on ISP interconnection links
[Clark2020]
* Favale, T., Soro, F., Trevisan, M., Drago, I., and Mellia, M.:
Campus traffic and e-Learning during COVID-19 pandemic
[Favale2020]
* Feldmann, A., Gasser, O., Lichtblau, F., Pujol, E., Poese, I.,
Dietzel, C., Wagner, D., Wichtlhuber, M., Tapiador, J., Vallina-
Rodriguez, N., Hohlfeld, O., and Smaragdakis, G.: A view of
Internet Traffic Shifts at ISP and IXPs during the COVID-19
Pandemic [Feldmann2020]
* Fontugne, R., Shah, A., and Cho, K.: The Impact of COVID-19 on
Last-mile Latency [Fontugne2020]
* Gillmor, D.: Vaccines, Privacy, Software Updates, and Trust
[Gillmor2020]
* Gu, Y. and Li, Z. Covid 19 Impact on China ISP's Network Traffic
Pattern and Solution Discussion [Gu2020]
* Jennings, C. and Kozanian, P.: WebEx Scaling During Covid
[Jennings2020]
* Lutu, A., Perino, D., Bagnulo, M., Frias-Martinez, E., and
Khangosstar, J.: A Characterization of the COVID-19 Pandemic
Impact on a Mobile Network Operator Traffic [Lutu2020]
* Mok, Ricky, and claffy, kc: Measuring the impact of COVID-19 on
cloud network performance [Mok2020]
* Kirsty P: IAB COVID-19 Network Impacts [Kirsty2020]
6. Workshop participants
The following is an alphabetical list of participants in the
workshop.
* Jari Arkko (Ericsson/IAB)
* Ben Campbell (Independent/IAB)
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* Andrew Campling (419 Consulting)
* Kenjiro Cho (IIJ)
* kc Claffy (CAIDA)
* David Clark (MIT CSAIL)
* Chris Dietzel (DE-CIX)
* Idilio Drago (University of Turin)
* Stephen Farrell (Trinity College Dublin/IAB)
* Nick Feamster (University of Chicago)
* Anja Feldmann (Max Planck Institute for Informatics)
* Romain Fontugne (IIJ Research Lab)
* Oliver Gasser (Max Planck Institute for Informatics)
* Daniel Kahn Gillmor (ACLU)
* Yunan Gu (Huawei)
* Oliver Hohlfeld (Brandenburg University of Technology, BTU)
* Jana Iyengar (Fastly)
* Cullen Jennings (Cisco/IAB)
* Mirja Kuhlewind (Ericsson/IAB)
* Franziska Lichtblau (Max Planck Institute for Informatics)
* Dominique Lazanski
* Zhenbin Li (Huawei/IAB)
* Jason Livingood (Comcast)
* Andra Lutu (Telefonica Research)
* Vesna Manojlovic (RIPE NCC)
* R Martin EC (?)
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* Matt Matthis (Google)
* Larry Masinter (Retired)
* Jared Mauch (Akamai/IAB)
* Deep Medhi (NSF)
* Marco Mellia (Politecnico di Torino)
* Ricky Mok (CAIDA)
* Karen O'Donoghue (Internet Society)
* Kirsty P (NCSC)
* Diego Perino (Telefonica Research)
* Colin Perkins (University of Glasgow/IRTF/IAB)
* Enric Pujol (Benocs)
* Anant Shah (Verizon Media Platform)
* Francesca Soro (Politecnico di Torino)
* Brian Trammell (Google)
* Gergios Tselentis (European Commission)
* Martino Trevisan
* Lan Wang (University of Memphis)
* Rob Wilton (Cisco)
* Jiankang Yao (CNNIC)
* Lixia Zhang (UCLA)
7. Program Committee
The workshop Program Committee members were Jari Arkko, Stephen
Farrell, Cullen Jennings, Colin Perkins, Ben Campbell, and Mirja
Kuehlewind.
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8. Acknowledgments
The authors would like to thank the workshop participants, the
members of the IAB, the program committee, the participants in the
architecture discussion list for interesting discussions, and Cindy
Morgan for the practical arrangements.
Further special thanks to those participants who also contributed to
this report: Romain Fontugne provided text based on his blog post at
https://eng-blog.iij.ad.jp/archives/7722; Ricky Mok for text on cloud
platform; Martino Trevisan for text on campus networks; David Clark
on congestion measurements at interconnects; Oliver Hohlfeld for the
text on traffic growth, changes in traffic shifts, campus networks,
and interconnections; Andra Lutu on mobile networks; And thanks to
Jason Livingood for his review and additions.
9. Informative References
[Afxanasyev2020]
Afxanasyev, A., Wang, L., Yeh, E., Zhang, B., and L.
Zhang, "Identifying the Disease from the Symptoms: Lessons
for Networking in the COVID-19 Era", Position paper in the
2020 IAB COVID-19 Network Impacts workshop. , October
2020.
[Arkko2020]
Arkko, J., "Observations on Network User Behaviour During
COVID-19", Position paper in the 2020 IAB COVID-19 Network
Impacts workshop. , October 2020.
[Bronzino2020]
Bronzino, F., Culley, E., Feamster, N., Liu, S.,
Livingood, J., and P. Schmitt, "IAB COVID-19 Workshop:
Interconnection Changes in the United States", Position
paper in the 2020 IAB COVID-19 Network Impacts workshop. ,
October 2020.
[Campling2020]
Campling, A. and D. Lazanski, "Will the Internet Still Be
Resilient During the Next Black Swan Event?", Position
paper in the 2020 IAB COVID-19 Network Impacts workshop. ,
October 2020.
[Cho2020] Cho, K., "On the COVID-19 Impact to broadband traffic in
Japan", Position paper in the 2020 IAB COVID-19 Network
Impacts workshop. , October 2020.
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[Clark2020]
Clark, D., "Measurement of congestion on ISP
interconnection links", Position paper in the 2020 IAB
COVID-19 Network Impacts workshop. , October 2020.
[Comcast2020]
Comcast, ., "COVID-19 Network Update",
https://corporate.comcast.com/covid-19/network/may-20-2020
, May 2020.
[ConsumerlabReport2020]
Ericsson Consumer & IndustryLab, ., "Keeping consumers
connected in a COVID-19 context",
https://www.ericsson.com/en/reports-and-
papers/consumerlab/reports/keeping-consumers-connected-
during-the-covid-19-crisis , June 2020.
[Favale2020]
Favale, T., Soro, F., Trevisan, M., Drago, I., and M.
Mellia, "Campus traffic and e-Learning during COVID-19
pandemic", Position paper in the 2020 IAB COVID-19 Network
Impacts workshop. , October 2020.
[Feldmann2020]
Feldmann, A., Gasser, O., Lichtblau, F., Pujol, E., Poese,
I., Dietzel, C., Wagner, D., Wichtlhuber, M., Tapiador,
J., N Vallina-Rodriguez, ., Hohlfeld, O., and G.
Smaragdakis, "A view of Internet Traffic Shifts at ISP and
IXPs during the COVID-19 Pandemic", Position paper in the
2020 IAB COVID-19 Network Impacts workshop. , October
2020.
[Fontugne2020]
Fontugne, R., Shah, A., and K. Cho, "The Impact of
COVID-19 on Last-mile Latency", Position paper in the 2020
IAB COVID-19 Network Impacts workshop. , October 2020.
[Fontugne2020-1]
Fontugne, R., Shah, A., and K. Cho, "Persistent Last-mile
Congestion: Not so Uncommon", Proceedings of the ACM
Internet Measurement Conference (IMC '20) , October 2020.
[Gillmor2020]
Gillmor, D., "Vaccines, Privacy, Software Updates, and
Trust", Position paper in the 2020 IAB COVID-19 Network
Impacts workshop. , October 2020.
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[Gu2020] Gu, Y. and Z. Li, "Covid 19 Impact on China ISP's Network
Traffic Pattern and Solution Discussion", Position paper
in the 2020 IAB COVID-19 Network Impacts workshop. ,
October 2020.
[Jennings2020]
Jennings, C. and P. Kozanian, "WebEx Scaling During
Covid", Position paper in the 2020 IAB COVID-19 Network
Impacts workshop. , October 2020.
[Kirsty2020]
Kirsty P, ., "IAB COVID-19 Network Impacts", Position
paper in the 2020 IAB COVID-19 Network Impacts workshop. ,
October 2020.
[Lutu2020] Lutu, A., Perino, D., Bagnulo, M., Frias-Martinez, E., and
J. Khangosstar, "A Characterization of the COVID-19
Pandemic Impact on a Mobile Network Operator Traffic",
Position paper in the 2020 IAB COVID-19 Network Impacts
workshop. , October 2020.
[McKinsey2020]
Boland, B., De Smet, A., Palter, R., and A. Sanghvi,
"Reimagining the office and work life after COVID-19", htt
ps://www.mckinsey.com/~/media/McKinsey/Business%20Function
s/Organization/Our%20Insights/Reimagining%20the%20office%2
0and%20work%20life%20after%20COVID%2019/Reimagining-the-
office-and-work-life-after-COVID-19-final.pdf , June 2020.
[Mok2020] Mok, R. and . kc claffy, "Measuring the impact of COVID-19
on cloud network performance", Position paper in the 2020
IAB COVID-19 Network Impacts workshop. , October 2020.
[NCTA2020] NCTA, ., "COVID-19: How Cable's Internet Networks Are
Performing: Metrics, Trends & Observations",
https://www.ncta.com/COVIDdashboard , 2020.
[Vodafone2020]
Vodafone, ., "An update on Vodafone's networks",
https://www.vodafone.com/covid19/news/update-on-vodafone-
networks , April 2020.
[WorkplaceAnalytics2020]
Lister, K., "Work-At-Home After Covid-19—Our Forecast",
https://globalworkplaceanalytics.com/work-at-home-after-
covid-19-our-forecast , 2020.
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Authors' Addresses
Jari Arkko
Ericsson
Email: jari.arkko@ericsson.com
Stephen Farrell
Trinity College Dublin
Email: stephen.farrell@cs.tcd.ie
Mirja Kühlewind
Ericsson
Email: mirja.kuehlewind@ericsson.com
Colin Perkins
University of Glasgow
Email: csp@csperkins.org
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