This October 2020 issue contains five technical papers, the third paper of our education series, as well as three editorial notes.

In anycast deployments, knowing how traffic will be distributed among the locations is challenging. In this paper, we propose a technique for partitioning the Internet using passive measurements of existing anycast deployments such that all IP addresses within a partition are routed to the same location for an arbitrary anycast deployment. One IP address per partition may then represent the entire

IoT deployments targeting different application domains are being unfolded at various administrative levels such as countries, states, corporations, or even individual households. Facilitating data transfers between deployed sensors and back-end cloud services is an important aspect of IoT deployments. These data transfers are usually done using Low Power WAN technologies (LPWANs) that have low power

The IPX Network interconnects about 800 Mobile Network Operators (MNOs) worldwide and a range of other service providers (such as cloud and content providers). It forms the core that enables global data roaming while supporting emerging applications, from VoLTE and video streaming to IoT verticals. This paper presents the first characterization of this, so-far opaque, IPX ecosystem and a first-of-its-kind

Mobile devices have become the primary mode of Internet access. Yet, differences in mobile hardware resources, such as device memory, coupled with the rising complexity of Web pages can lead to widely different quality of experience for users. In this work, we analyze how device memory usage affects Web browsing performance. We quantify the memory footprint of popular Web pages over different mobile

Quantum computing is threatening current cryptography, especially the asymmetric algorithms used in many Internet protocols. More secure algorithms, colloquially referred to as Post-Quantum Cryptography (PQC), are under active development. These new algorithms differ significantly from current ones. They can have larger signatures or keys, and often require more computational power. This means we cannot

This paper focuses on the K-12 educational activities of COSMOS-Cloud enhanced Open Software defined MObile wireless testbed for city-Scale deployment. The COSMOS wireless reasearch testbed is being deployed in West Harlem (New York City) as part of the NSF Platforms for Advanced Wireless Research (PAWR) program. COSMOS' approach for K-12 education is twofold: (i) create an innovative and concrete

Many countries are deploying Covid-19 contact tracing apps that use Bluetooth Low Energy (LE) to detect proximity within 2m for 15 minutes. However, Bluetooth LE is an unproven technology for this application, raising concerns about the efficacy of these apps. Indeed, measurements indicate that the Bluetooth LE received signal strength can be strongly affected by factors including (i) the model of

Since the start of the COVID-19 pandemic, technology enthusiasts have pushed for digital contact tracing as a critical tool for breaking the COVID-19 transmission chains. Motivated by this push, many countries and companies have created apps that enable digital contact tracing with the goal to identify the chain of transmission from an infected individual to others and enable early quarantine. Digital

Controlling an opaque system by reading some "dials" and setting some "knobs," without really knowing what they do, is a hazardous and fruitless endeavor, particularly at scale. What we need are transparent networks, that start at the top with a high-level intent and map all the way down, through the control plane to the data plane. If we can specify the behavior we want in software, then we can check

This July 2020 issue contains four technical papers, the second paper of our education series, as well as two editorial notes.

Transport Layer Security (TLS) 1.3 is a redesign of the Web's most important security protocol. It was standardized in August 2018 after a four year-long, unprecedented design process involving many cryptographers and industry stakeholders. We use the rare opportunity to track deployment, uptake, and use of a new mission-critical security protocol from the early design phase until well over a year

Knowing domain names associated with traffic allows eavesdroppers to profile users without accessing packet payloads. Encrypting domain names transiting the network is, therefore, a key step to increase network confidentiality. Latest efforts include encrypting the TLS Server Name Indication (eSNI extension) and encrypting DNS traffic, with DNS over HTTPS (DoH) representing a prominent proposal. In

In this paper, we re-implement a recent work published in Usenix Security 2018: "Acquistional Rule Based Engine for Discovering Internet-of-Things Devices". The paper introduced an NLP-based engine for automatically identifying the type, vendor, and product of IoT devices given banner data as input. We report on our efforts to reproduce the original implementation of the engine, documenting ambiguities

Buffering architectures and policies for their efficient management are one of the core ingredients of network architecture. However, despite strong incentives to experiment with and deploy new policies, opportunities for changing or automatically choosing anything beyond a few parameters in a predefined set of behaviors still remain very limited. We introduce a novel buffer management framework based

To reflect the importance of network technologies, networking courses are now part of the core materials of Computer Science degrees. We report our experience in jointly developing an open-source ebook for the introductory course, and a series of open educational resources for both the introductory and advanced networking courses. These ensure students actively engage with the course materials, through

Due to the COVID-19 pandemic, the organizing committee of the 2020 edition of the Passive and Active Measurement (PAM) conference decided to organize it as a virtual event. Unfortunately, little is known about designing and organizing virtual academic conferences in the networking domain and their impacts on the participants' experience. In this editorial note, we first provide challenges and rationale

This editorial note aims to first inform the SIGCOMM community on the reviewing process in place currently at CCR, and second, share our plans to make CCR a more open and welcoming venue by making changes to the review process, adding more value to the SIGCOMM community.

Presentation of the April 2020 issue of CCR.

RIPE IPmap is a multi-engine geolocation platform operated by the RIPE NCC. One of its engines, single-radius, uses active geolocation to infer the geographic coordinates of target IP addresses. In this paper, we first introduce the methodology of IPmap's single-radius engine, then we evaluate its accuracy, coverage, and consistency, and compare its results with commercial geolocation databases. We

A commonly held belief is that traffic engineering and routing changes are infrequent. However, based on our measurements over a number of years of traffic between data centers in one of the largest cloud provider's networks, we found that it is common for flows to change paths at ten-second intervals or even faster. These frequent path and, consequently, latency variations can negatively impact the

Understanding web co-location is essential for various reasons. For instance, it can help one to assess the collateral damage that denial-of-service attacks or IP-based blocking can cause to the availability of co-located web sites. However, it has been more than a decade since the first study was conducted in 2007. The Internet infrastructure has changed drastically since then, necessitating a renewed

Artifact badging aims to rank the quality of submitted research artifacts and promote reproducibility. However, artifact badging may not indicate inherent design and evaluation limitations.

The strict low-latency requirements of applications such as virtual reality, online gaming, etc., can not be satisfied by the current Internet. This is due to the characteristics of classic TCP such as Reno and TCP Cubic which induce high queuing delays when used for capacity-seeking traffic, which in turn results in unpredictable latency. The Low Latency, Low Loss, Scalable throughput (L4S) architecture

Each year at ETH Zurich, around 100 students collectively build and operate their very own Internet infrastructure composed of hundreds of routers and dozens of Autonomous Systems (ASes). Their goal? Enabling Internet-wide connectivity. [email protected] find this class-wide project to be invaluable in teaching our students how the Internet infrastructure practically works. Among others, our students

On 9-11 December 2019, CAIDA hosted the 10th interdisciplinary Workshop on Internet Economics (WIE) at UC San Diego's Supercomputer Center. This workshop series provides a forum for researchers, Internet facilities and service providers, technologists, economists, theorists, policymakers, and other stakeholders to exchange views on current and emerging economic and policy debates. This year's meeting

Reproducibility: the extent to which consistent results are obtained when an experiment is repeated, is important as a means to validate experimental results, promote integrity of research, and accelerate follow up work. Commitment to artifact reviewing and badging seeks to promote reproducibility and rank the quality of submitted artifacts.

We dispute the authors' claim that SRPT is the crucial factor in achieving good FCT performance in datacenter networks.

We investigated Internet eXchange Points (IXPs) deployed across Latin America. We discovered that many Latin American states have been actively involved in the development of their IXPs. We further found a correlation between the success of a national IXP and the absence of local monopolistic ASes that concentrate the country's IPv4 address space. In particular, three IXPs have been able to gain local

Motivated by the rapid emergence of programmable switches, programmable network interface cards, and software packet processing, this paper asks: given a network task (e.g., virtualization or measurement) in a programmable network, should we implement it at the network's end hosts (the edge) or its switches (the core)? To answer this question, we analyze a range of common network tasks spanning virtualization

This January 2020 issue starts the fiftieth volume of Computer Communication Review. This marks an important milestone for our newsletter. This issue contains four technical papers and three editorial notes. In C-Share: Optical Circuits Sharing for Software-Defined Data-Centers, Shay Vargaftik and his colleagues tackle the challenge of designing data-center networks that combine optical circuit switches

Several "NewSpace" companies have launched the first of thousands of planned satellites for providing global broadband Internet service. The resulting low-Earth-orbit (LEO) constellations will not only bridge the digital divide by providing service to remote areas, but they also promise much lower latency than terrestrial fiber for long-distance routes. We show that unlocking this potential is non-trivial:

The Internet topology has significantly changed in the past years. Today, it is richly connected and flattened. Such a change has been driven mostly by the fast growth of peering infrastructures and the expansion of Content Delivery Networks as alternatives to reduce interconnection costs and improve traffic delivery performance. While the topology evolution is perceptible, it is unclear whether or

The Network Neutrality (NN) debate refers to the battle over the design of a regulatory framework for preserving the Internet as a public network and open innovation platform. Fueled by concerns that broadband access service providers might abuse network management to discriminate against third party providers (e.g., content or application providers), policymakers have struggled with designing rules

On July 24-25, 2018, MIT hosted an invitation-only workshop for network researchers from academia, industry, and the policy community engaged in the design and operation of test schemes to measure broadband access, in order to address the measurement challenges associated with highspeed (gigabit) broadband Internet access services. The focus of the workshop was on assessing the current state-of-the-art

Integrating optical circuit switches in data-centers is an on-going research challenge. In recent years, state-of-the-art solutions introduce hybrid packet/circuit architectures for different optical circuit switch technologies, control techniques, and traffic re-routing methods. These solutions are based on separated packet and circuit planes that cannot utilize an optical circuit with flows that

As SIGCOMM turns 50, it's interesting to ask how networking research has evolved over time. This is a set of personal observations about the "mindset" associated with Internet research.

While placing the paper "XORs in the Air" in the context of the theoretical and practical understanding of network coding, we present a view of the progress of the field of network coding, In particular, we examine the interplay of theory and practice in the field.

On 16-17 April 2018, CAIDA hosted its eleventh Workshop on Active Internet Measurements (AIMS-11). This workshop series provides a forum for stakeholders in Internet active measurement projects to communicate their interests and concerns, and explore cooperative approaches to maximizing the collective benefit of deployed infrastructure and gathered data. An overarching theme this year was scaling the

Recent years have seen a slew of papers on datacenter congestion control mechanisms. In this editorial, we ask whether the bulk of this research is needed for the common case where congestion control involves hosts responding to simple congestion signals from the network and the performance goal is reducing some average measure of flow completion time. We raise this question because we find that, out

Anycast has been widely adopted by today's Internet services, including DNS, CDN, and DDoS protection, in which the same IP address is announced from distributed locations and clients are directed to the topologically-nearest service replica. Prior research has focused on various aspects of anycast, either its usage in particular services such as DNS or characterizing its adoption by Internet-wide

In the modern era of the mobile apps (part of the era of surveillance capitalism, a famously coined term by Shoshana Zuboff), huge quantities of data about individuals and their activities offer a wave of opportunities for economic and societal value creation. However, the current personal data ecosystem is mostly de-regulated, fragmented, and inefficient. On one hand, end-users are often not able

The TCP Macroscopic Model will be completely obsolete soon. It was a closed form performance model for Van Jacobson's landmark congestion control algorithms presented at Sigcomm'88. Jacobson88 requires relatively large buffers to function as intended, while Moore's law is making them uneconomical. BBR-TCP is a break from the past, unconstrained by many of the assumptions and principles defined in Jacobson88

Brief notes relating to the Computer Communication Review in 1975--1976.

A brief description of how SIGCOMM's quarterly newsletter evolved into an entry-level journal.

In the policy realm what we call "Internet issues" are not actually "Internet" issues-they are well-pedigreed social, political, cultural, and economic issues, for which we clever technologists have provided a rich new environment in which to grow and multiply. It follows that the people best prepared to tackle "Internet" issues may be thoughtful professionals in fields such as behavioral psychology

We look back at our 1987 paper, "Fragmentation Considered Harmful," to explain why we wrote it, how the prevalence of fragmentation was reduced by approaches such as Path MTU Discovery, and how fragmentation-related issues still lurk in today's Internet. Our paper listed several reasons why we thought fragmentation was harmful; some were more true in 1987 than they are today, and after our paper was

The original Ethernet design used CSMA/CD on a broadcast cable. Even after it became commercially popular, many people expressed concerns that Ethernet could not efficiently use the full channel bandwidth. In our 1988 paper, "Measured Capacity of an Ethernet: Myths and Reality," we reported on experiments we ran showing that, even under relatively heavy loads, Ethernet typically still performed well

We introduced the concept of a digital fountain as a scalable approach to reliable multicast, realized with fast and practical erasure codes, in a paper published in ACM SIGCOMM '98. This invited editorial, on the occasion of the 50th anniversary of the SIG, reflects on the trajectory of work leading up to our approach, and the numerous developments in the field in the subsequent 21 years. We discuss

Network programmability has metamorphosed over the past twenty years from the controversial research vision of active networks, through PlanetLab, to the juggernaut of SDN and OpenFlow that has swept industry. Now PISA switches are emerging with support for protocol-independent reconfigurability. We reflect on how network architecture has evolved along a different path than we had foreseen to arrive

This article discusses the events that led to the publication of my paper 'A Control-Theoretic Approach to Flow Control' that won the Best Student Paper Award in 1991 and a Test-of-Time Award in 2007.

There's no way to understand today's networks without knowing the history. Too often, network protocols are taught as 'memorize the details of what is currently deployed', which creates a lot of confusion, and certainly does not encourage critical thinking. Some decisions have made today's networks unnecessarily complex and less functional. But surprisingly, mechanisms that were created out of necessity

On the occasion of the fiftieth anniversary of SIGCOMM, this article contains the reflections of a past SIGCOMM chair on the field of networking over the past few decades.

This article provides a brief retrospective on the evolution of Delay Tolerant Networking since 2003.

This editorial is an outgrowth of our research efforts that resulted in the SIGCOMM'93 paper [1] entitled On the self-similar nature of Ethernet traffic. We discuss some lessons we have learned as we have watched the published findings being absorbed by the scientific community in general and the networking community in particular. We focus on aspects that have remained relevant today, especially at

The queueing delay faced by a packet is arguably the largest source of uncertainty during its journey. It therefore seems crucial that we understand how big the buffers should be in Internet routers. Our 2004 Sigcomm paper revisited the existing rule of thumb that a buffer should hold one bandwidth-delay product of packets. We claimed that for long-lived TCP flows, it could be reduced by √N, where

We reflect on the historical context that lead to Propane, a high-level language and compiler to help network operators bridge the gap between network-wide routing objectives and low-level configurations of devices that run complex, distributed protocols. We also highlight the primary contributions that Propane made to the networking literature and describe ongoing challenges. We conclude with an important

Network researchers know that packets are not always evenly spaced, they sometimes arrive in bursts. This burstiness is also present in history. Important events sometimes occur almost simultaneously even if there is no direct relationship between them. Fifty years ago, several historical events took place within a period of a few months. In July, after years of efforts, NASA engineers successfully

The ever-increasing demand for data has forced cellular networks towards advanced multi-antenna (MIMO) techniques. However, advanced MIMO solutions such as massive MIMO, coordinated multi-point, distributed MIMO, and multi-user MIMO, all require the base station to know the downlink channels to the client. In the absence of this information, the base station cannot beamform its signal to its users

We briefly describe the history behind the Ethane paper and its ultimate evolution into SDN and beyond.