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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
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
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   extracted from this document must include Simplified BSD License text
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   provided without warranty as described in the Simplified BSD License.

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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