The April 2023 issue

This April 2023 issue contains one technical paper and four editorial notes.

The technical paper, Vulnerability Disclosure Considered Stressful, by Giovane C. M. Moura and colleagues, describes the authors’ experience running a Coordinated Vulnerability Disclosure (CVD) for the TSUNAME vulnerability. The process of Coordinated Vulnerability Disclosure (CVD) is widely viewed as the gold standard in the notification process that follows the discovery of a vulnerability, aiming at getting operators to patch their systems before attackers can do much harm. However, the task of setting up a CVD can be daunting because security researchers have too few guidelines and experience reports to rely on when they are faced with setting up their own process. This paper is helpful to our community as it may help anyone who may have to report vulnerabilities during their work.

Then, we have four editorial notes. In the first, Measuring Broadband America: A Retrospective on Origins, Achievements, and Challenges, Eric Burger and colleagues present a retrospective on the “Measuring Broadband America” program, run by the United States Federal Communications Commission (FCC), which continually measures and releases data on the performance of consumer broadband access networks in the US. In the second, Recent Trends on Privacy-Preserving Technologies under Standardization at the IETF, Pratyush Dikshit and colleagues present an overview of the privacy-preserving mechanisms for layer 3 (i.e. IP) and above that are currently under standardization at the IETF. The third editorial note, Report of 2021 DINRG Workshop on Centralization in the Internet, by Christian Huitema and colleagues, reports on the workshop on Centralization in the Internet hosted by the Internet Research Task Force (IRTF) Research Group on Decentralizing the Internet (DINRG), on June 3, 2021. The fourth editorial note, A Retrospective on Campus Network Traffic Monitoring, by Martin Arlitt and colleagues, shares some of the authors’ experiences about monitoring the traffic on their campus Internet link for about two decades.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The January 2023 issue

This January 2023 issue contains five technical papers.

The first technical paper, Fast In-kernel Traffic Sketching in eBPF, by Sebastiano Miano and colleagues, studies how to develop high-performance network measurements in eBPF. The extended Berkeley Packet Filter (eBPF) allows to dynamically load and run micro-programs in the Linux kernel without the need for recompiling it. The authors use sketches as case-study, given their ability to support a wide-range of tasks while providing low-memory footprint and accuracy guarantees. The authors apply their approach to a state-of-the-art sketch for user-space networking, show that best practices in user-space networking cannot be directly applied to eBPF, and improve its performance by 40% compared to a naive implementation. The lessons learned in this paper are not only applicable to network measurement algorithms but extend to a wide variety of eBPF-based programs.

The second technical paper, Comparing User Space and In-Kernel Packet Processing for Edge Data Centers, by Federico Parola and colleagues, is motivated by the increased availability of small data centers at the edge of the network. Network operators are moving their network functions in these computing facilities. However, commonly used technologies for data plane processing such as DPDK, based on kernel-bypass primitives, provide high performance but at the cost of rigid resource partitioning. This is unsuitable for edge data centers in which efficiency demands both general-purpose applications and data-plane telco workloads to be executed on the same (shared) physical machines. In this respect, eBPF/XDP looks a more appealing solution, thanks to its capability to process packets in the kernel, achieving a higher level of integration with non-data plane applications albeit with lower performance than DPDK. This research addresses the premise that in edge data centers, with limited resources, packet processing and protocol stack workloads are likely to be consolidated within the same servers. As a result, kernel-based XDP may be a more attractive option than DPDK-based data plane processing. This motivates the need for a deeper understanding of kernel-based XDP and its various forms to support different workload types.

The third technical paper, P4RROT: Generating P4 Code for the Application Layer, by Csaba Györgyi and colleagues, proposes a new code generation mechanism to streamline application-level offloads expressed in the P4 programming language. The authors present P4RROT, a new library that allow developers to write application layer logic in Python which is then converted in P4. The authors discuss the pain points and challenges for automatic code generation and show the applicability of P4RROT in two different contexts: a publish-subscribe sensor data processing system and a real-time data streaming engine, supporting MQTT-SN and MoldUDP traffic.

The fourth technical paper, The Slow Path Needs an Accelerator Too!, by Annus Zulfiqar and colleagues, shows that the slow path is set to become a new key bottleneck in Software-Defined Networks (SDNs). The authors present their vision of a new Domain Specific Accelerator (DSA) for the slow path at the end host that sits between the hardware-offloaded data plane and the logically-centralized control plane. They also discuss open problems and call on the networking community to creatively address this emerging issue.

The fifth technical paper, Who squats IPv4 Addresses?, by Loqman Salamatian and colleagues, analyzes the phenomenon of squatted IP space: IPv4 addresses that operators use although they have not been allocated to them. This is possible because larger IPv4 blocks exist that have been allocated to organizations which never announced them in the global routing system. The authors draw on a very large data set of traceroutes and develop a heuristic to identify how squat space is used, by whom, and what the implications for Internet routing and the operator communities are. This paper is a significant contribution of interest to everyone with an interest in the operation of Internet routing and larger networks.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The October 2022 issue

This October 2022 issue contains two technical papers and one editorial note.

The first technical paper, LGC-ShQ: Datacenter Congestion Control with Queueless Load-based ECN Marking, by Kristjon Ciko and colleagues, provides a thorough performance evaluation of LGC-ShQ, a novel congestion control (CC)mechanism for data-centers. LGC-ShQ’s performance are compared (over Linux) against HULL, the closest solution in the state-of-the-art.

The second technical paper, Topology and Geometry of the Third-Party Domains Ecosystem: Measurement and Applications, by Costas Iordanou and colleagues, studies the network of the third-party domains by observing the domains’ interactions within users’ browsers from all over the globe. The authors then discuss the structural properties of the corresponding network. The results provide a new perspective on understanding the ecosystem’s organization.

We have one editorial note. In Rethinking SIGCOMM’s Conferences: Making Form Follow Function, Scott Shenker asks whether our current practice of highly selective conferences is helping us achieve SIGCOMM’s research goals. This essay contends that there is a significant mismatch between what SIGCOMM’s goals should be and what our current practices achieve, and proposes a radical restructuring of our conferences that would provide better alignment and, as an additional benefit, a stronger sense of community.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The July 2022 issue

This July 2022 issue contains one technical paper and two editorial notes.

The technical paper, The Packet Number Space Debate in Multipath QUIC, by Quentin De Coninck, deals with how QUIC packets should be numbered over multiple paths. This work provides a comparison between the usage of a single (shared) or multiple packet space numbers for QUIC multipath. The main outcome of the evaluation is that using multiple packet number spaces has the advantage that packet losses can be detected while maintaining a significantly lower state at the receiver. Also, it allows using fewer signalling frames at the cost of a more profound modification of the QUIC protocol.

We have two editorial notes. The first one, The multiple roles that IPv6 addresses can play in today’s Internet, by Maxime Piraux and his colleagues, argues that the large IPv6 addressing space allows reconsidering how IP addresses are used and enables improving, simplifying and scaling the Internet. The second, AppClassNet: A commercial-grade dataset for application identification research by Wang Chao and his colleagues, releases a commercial-grade dataset for benchmarking traffic classification and management methodologies. AppClassNet is significantly larger than the datasets generally available to the academic community.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The April 2022 issue

This April 2022 issue contains five technical papers and two editorial notes.

The first technical paper, Data-Plane Security Applications in Adversarial Settings, by Liang Wang and colleagues, investigates security issues that may arise when creating and running data-plane applications for programmable switches. This work moves security analysis and design forward in this particular area. This paper also calls for a more thorough rethinking of security for data-plane applications for programmable switches.

The second technical paper, One Bad Apple Can Spoil Your IPv6 Privacy, by Said Jawad Saidi and colleagues, leverages IPv6 passive measurements to pinpoint that a non-negligible portion of devices encodes their MAC address in their IPv6 address. This threatens users’ privacy, allowing content providers and CDNs to consistently track users and their devices across multiple sessions and locations. Overall, the paper is an excellent contribution toward privacy-by-design solutions and a nicely executed measurements study that clarifies the problem and provides solid suggestions to mitigate the problem.

The third technical paper, Hyper-Specific Prefixes: Gotta Enjoy the Little Things in Interdomain Routing, by Khwaja Zubair Sediqi and colleagues, investigates the presence of high-specific prefixes (HSP) on the BGP Internet routing during the last decade. These prefixes are more-specific than /24 (/48) for IPv4 (IPv6) and are commonly filtered by Autonomous Systems operators. Overall this paper offers a nice contribution to the understanding of the BGP universe, with a clear message and a nice quantification of the phenomenon. The authors clearly present and motivate the work, offering also to not experts a nice view of the routing complexity of the internet nowadays.

The fourth technical paper, Programming Socket-Independent Network Functions with Nethuns, by Nicola Bonelli and colleagues, proposes a new solution to transparently develop packet-processing programs on top of different network I/O frameworks. The authors design and develop an open-source library, nethuns, serving as a unified programming abstraction for network functions that natively supports multi-core programming. Not only is this work very relevant to our community, but also the code is released open-source through a BSD license, which can be used to foster more research in the area, towards unifying programming mechanisms of end-host networking.

The fifth technical paper, Measuring DNS over TCP in the Era of Increasing DNS Response Sizes: A View from the Edge, by Mike Kosek and colleagues, studies one of the foundations of today’s Internet: the Domain Name Service (DNS). The original RFC document of DNS instructs to send queries either over UDP (DoUDP) or TCP (DoTCP). This paper presents a measurement study on DoTCP focusing on two perspectives: failure rates and response times.

Finally, we have two editorial notes. A Case for an Open Customizable Cloud Network, by Dean H. Lorenz and his colleagues, argues for the desirability of the new ecosystem of managed network solutions to connect to the Cloud, outlines the main requirements and sketches possible solutions. Recommendations for Designing Hybrid Conferences, by Vaibhav Bajpai and colleagues, presents guidelines and considerations–spanning technology, organization and social factors–for organizing successful hybrid conferences.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The January 2022 issue

This January 2022 issue contains three technical papers and four editorial notes.

The first technical paper, Zeph & Iris Map the Internet – A resilient reinforcement learning approach to distributed IP route tracing, by Matthieu Gouel and colleagues, proposes to improve topology discovery by optimizing the use of existing probing resources. This can be done by intelligently allocating probing directives to vantage points. The system is based on the inter-working of two components: Iris, which takes care of the route tracing, and Zeph, which coordinates Iris’s measurements. The results in the paper show that Zeph, in combination with Iris, are able to facilitate fast topology measurements from geographically distributed vantage points.

The second technical paper, Towards Retina-Quality VR Video Streaming: 15ms Could Save You 80\% of Your Bandwidth, by Luke Hsiao and colleagues, investigates how to provide retina-quality video streaming in virtual reality (VR). The paper studies the impact of the motion-to-photon latency — the time between a change in the viewer’s gaze and the resulting change in the display’s pixels — on a VR system. This metric is paramount for VR systems since it impacts video compression. The paper shows, experimentally, that a client and streaming server system with sub-15 ms end-to-end motion-to-photon latency benefit from 5x better video compression than in presence of larger latencies. The paper also shows how to build such a low latency system both hardware and software-wise.

The third technical paper, Towards client-side active measurements without application control, by Palak Goenka and colleagues, proposes to harness Network Error Logging (NEL) to enable active client-side measurements (RTT and connection availability) by dynamically modifying the HTTPS endpoint where NEL reports should be uploaded. Network Error Logging (NEL) is a W3C standard which defines how web servers can receive from a browser reports about performance and failures of web requests. The techniques used in the paper enable active client-side measurements in the browser without requiring Javascript code injection, which is the current and more invasive state of the art solution.

Finally, we have four editorial notes. Roadmap for Edge AI: A Dagstuhl Perspective, by Aaron Yi Ding and his colleagues, based on the collective input of Dagstuhl Seminar (21342), presents a comprehensive discussion on AI methods and capabilities in the context of edge computing, referred as Edge AI. Then, M-Lab: User initiated Internet data for the research community, by Phillipa Gill and her colleagues, presents Measurement Lab (M-Lab), an open, distributed server platform on which researchers have deployed measurement tools. Important Concepts in Data Communications, by Craig Partridge, presents one perspective about which concepts or ideas in data communications have proven to be enduring in the evolution of data communications. Finally, Answering Three Questions About Networking Research, by Jennifer Rexford and Scott Shenker, presents the first of a series of answers to three questions that were asked to panelists during HotNets’21, about how they pick their own research topics, what areas they would like to see more research on, and how they evaluate conference papers.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The October 2021 issue

This October 2021 issue contains two technical papers, two educational contributions, and one editorial note.

The first technical paper, When Latency Matters: Measurements and Lessons Learned, by Marco Iorio and colleagues, evaluates the “latency argument” for edge computing, i.e., that placing elastic computing and storage platforms in close proximity to end-users makes sense for latency-critical applications. The paper evaluates several sources of latency, including latency induced by core network routing inefficiencies, wired and wireless access network, transport protocol and application protocol. The paper concludes that moving data-centers close to the users is only a small part of the latency problems, and that solving it requires a more careful coordination of efforts across the network stack.

The second technical paper, REDACT: Refraction Networking from the Data Center, by Arjun Devraj and colleagues, extends the concept of refraction networking by assigning the edge router of a cloud datacenter the role of a decoy router.

The first educational contribution, Machine learning-based Analysis of COVID-19 Pandemic Impact on US Research Networks, by Mariam Kiran and colleagues, sheds light on the performance of a large network throughout the COVID-19 pandemic. Extensive traces are studied and analyzed, with a number of interesting findings using various statistical techniques.

The second educational contribution, An educational toolkit for teaching cloud computing, by Cosimo Anglano and colleagues, proposes the creation of a software layer to hide the specifics of the underlying cloud platforms from students, enabling them to perform their assignments atop a general API. The proposed approach is an innovative idea to improve the educational experience of students on cloud platforms.

Finally, we have an editorial note. Data-driven Networking Research: models for academic collaboration with industry (a Google point of view), by Jeffrey C. Mogul and his colleagues, describes collaboration models aimed at stimulating data-driven networking research. The authors describe specific areas where they would welcome proposals to work within those models.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The July 2021 issue

This July 2021 issue contains one technical paper, two educational contributions, as well as four editorial notes.

The technical paper, NemFi: Record-and-replay to emulate WiFi, by Abhishek kumar Mishra and colleagues, proposes a trace-driven WiFi emulator called NemFi, that allows modeling of transmission opportunities of uplink and downlink directions, packet loss, frame aggregation, and media access control behavior. The latter two concepts are unique for WiFi when compared with other similar tools that have been built for cellular networks.

The first educational contribution, The Graph Neural Networking Challenge: A Worldwide Competition for Education in AI/ML for Networks, by Jose Suarez-Varela and colleagues, proposes a ”challenge” to teach students about applications of AI/MLin computer networks. The authors describe a process to select a dataset, and a competition-based approach where participants must design a neural-network-based approach to infer properties of the dataset with as much accuracy as possible.

The second educational contribution, P4Pi: P4 on Raspberry Pi for Networking Education, by Sandor Laki and colleagues, presents a novel platform for networking education based on a Raspberry Pi, allowing students to program P4.

Then, we have four editorial notes. The first one, Limited Domains Considered Useful, by Brian Carpenter and his colleagues, argues not only that limited domains have been with us from the very beginning of the Internet but also that they have been shaping innovation of Internet technologies ever since, and will continue to do so.

The second editorial note, Collaboration in the IETF: An Initial Analysis of Two Decades in Email Discussions, by Michael Welzl and his colleagues, discusses the following question: when big players follow such a “shoot first, discuss later” approach, is IETF collaboration still “real”, or is the IETF now being (mis-)used to approve protocols for standardization when they are already practically established, without really actively involving anyone but the main proponents?

The third editorial note, Workshop on Overcoming Measurement Barriers to Internet Research (WOMBIR 2021) Final Report, by kc claffy and her colleagues, reports on the Workshop on Overcoming Measurement Barriers to Internet Research (WOMBIR), held earlier in 2021.

The fourth and last editorial note, A Square Law Revisited, by Brian Carpenter, revisits the approximate apparent growth of the globally addressable Internet in proportion to the square root of the host count.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The April 2021 issue

The April 2021 issue contains one technical paper as well as five editorial notes.

The technical paper, Surviving switch failures in cloud datacenters, by Rachee Singh and her colleagues, examines the nature of switch failures in the datacenters of a large commercial cloud provider. This work studies a cohort of over 180,000 switches with a variety of hardware and software configurations.

Then, we have five editorial notes. The first one, The Netivus Manifesto: Making Collaborative Network Management Easier for the Rest of Us, by Joseph Severini and his colleagues, studies operational issues faced by Small and Medium Enterprise (SME) network owners.

The second editorial note, Revitalizing the Public Internet By Making it Extensible, by Hari Balakrishnan and his colleagues, argues for the creation of an Extensible Internet that supports in-network services that go beyond best-effort packet delivery.

The third editorial note, Workshop on Internet Economics (WIE 2020) Final Report, by kc claffy and David Clark, reports on the 11th interdisciplinary Workshop on Internet Economics (WIE).

The fourth editorial note, SatNetLab: A call to arms for the next global Internet testbed, by Ankit Singla, lays out a case for networking researchers to collaboratively undertake the construction of SatNetLab, a research platform that enables experimentation across upcoming satellite-based networks.

The fifth editorial note, Great Educators in Computer Networking: Bruce Davie, by Matthew Caesar and Bruce Davie, is an interview, part of a series on Great Educators in Computer Networking, where some of the most impactful and skilled educators in our field are interviewed.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The January 2021 issue

This January 2021 issue contains three technical papers as well as two editorial notes.

The first technical paper, Distrinet: a Mininet Implementation for the Cloud, by Giuseppe Di Lena and his colleagues, proposes Distrinet, a distributed implementation of Mininet over multiple hosts, based on LXD/LXC, Ansible, and VXLAN tunnels. Distrinet is compatible with Mininet programs, generic and can deploy experiments on Linux clusters as well as on the Amazon EC2 cloud platform. Given how popular Mininet is for SDN evaluation, this contribution potentially provides a lot of value to our research community.

The second technical paper, Experience-Driven Research on Programmable Networks, by Hyojoon Kim and colleagues, presents a proof-of-concept to help researchers run experiments against their programmable network idea, in their own network. The authors present several data-plane applications as use cases that run on their campus and solve production network problems. While not fully reproducible, this paper is a good step towards encouraging similar efforts in our community.

Our third paper, The Case for Model-Driven Interpretability of Delay-based Congestion Control Protocols, by Muhammad Khan and his colleagues, presents a study of different delay-based congestion control algorithms for TCP. The proposed framework is flexible and allows to model delay-based protocols, by simplifying a congestion control protocol’s response into a guided random walk over a two-dimensional Markov model. The model is evaluated against actual traces collected in 3G/4G networks, and allows to get the intuition of which regime the congestion control loop is spending most of the time.

Then, we have two editorial notes. The first one, Italian Operators’ Response to the COVID-19 Pandemic, by Massimo Candela and Antonio Prado, reports on the actions undertaken by network operators in Italy in response to COVID-19. The second editorial note, What do Information Centric Networks, Trusted Execution Environments, and Digital Watermarking have to do with Privacy, the Data Economy, and their future?, by Nikolaos Laoutaris and Costas Iordanou, discusses how ICNs combined with trusted execution environments and digital watermarking can be combined to build a personal data overlay inter-network that has a plethora of desirable properties for end-users.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The October 2020 issue

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

The first technical paper, Partitioning the Internet using Anycast Catchments, by Kyle Schomp and Rami Al-Dalky, deals with anycast, one of the core operational strategies to improve service performance, availability and resilience. Anycast is widely used by cloud providers, content delivery networks (CDNs), major DNS operators and many more popular Internet services. However, anycast comes with limited visibility in how traffic will be distributed among the different server locations. The authors of this paper paper 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.

The second technical paper, LoRadar: LoRa Sensor Network Monitoring through Passive Packet Sniffing, by Kwon Nung Choi and colleagues, moves us to a very different topic, in the area of IoT, and in particular Low Power WAN technologies (LPWANs) such as Long Range (LoRa). This paper develops a software tool, LoRadar, to monitor LoRa’s medium access control protocol on commodity hardware via passive packet sniffing.

Our third paper, A first look at the IP eXchange Ecosystem, by Andra Lutu and her colleagues, deals with the very important topic of the IPX Network, which we use every time we roam with our smartphones and interconnects about 800 Mobile Network Operators (MNOs) worldwide. Despite its size, neither its organisation nor its operation are well known within our community. This paper provides a first analysis of the IPX network, which we hope will be followed by other works on this under-studied topic.

The fourth paper, Mobile Web Browsing Under Memory Pressure, by Ihsan Ayyub Qazi and colleagues, investigates the impact of memory usage on mobile devices in the context of web browsing. The authors present a study using landing page loading time and memory requirements for a number of Android-based smartphones using Chrome, Firefox, Microsoft Edge and Brave. The extensive results of this paper cover the effect of tabs, scrolling, the number of images, and the number of requests made for different objects.

The fifth paper, Retrofitting Post-Quantum Cryptography in Internet Protocols: A Case Study of DNSSEC, by Moritz Mueller and his colleagues, analyses the implications of different Post-Quantum Cryptography solutions in the context of Domain Name System Security Extensions. What makes this paper very interesting, is its timeliness, since the networking and security communities are currently investigating suitable alternatives for DNSSEC, and candidate solutions shall be selected by early 2022.

The sixth paper, also our third paper in the new education series, COSMOS Educational Toolkit: Using Experimental Wireless Networking to Enhance Middle/High School STEM Education, by Panagiotis Skrimponis and his colleagues, describes COSMOS, a general-purpose educational toolkit for teaching students about a variety of computer science concepts, including computer networking. The notable aspect of this work is that the COSMOS testbed has already been deployed and used by a large number of students, and has already demonstrated great value to the community.

Then, we have three editorial notes. The first two are coincidentally on the very timely topic of contact tracing. The first one, Coronavirus Contact Tracing: Evaluating The Potential Of Using Bluetooth Received Signal Strength For Proximity Detection, by Douglas J. Leith and Stephen Farrell, reports on the challenges faced when deploying Covid-19 contact tracing apps that use Bluetooth Low Energy (LE) to detect proximity. The second editorial note, Digital Contact Tracing: Technologies, Shortcomings, and the Path Forward, by Amee Trivedi and Deepak Vasisht, investigates the technology landscape of contact-tracing apps and reports on what they believe are the missing pieces. Our third and final editorial note, Using Deep Programmability to Put Network Owners in Control, by Nate Foster and colleagues, share their vision regarding deep programmability across the stack.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https://ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The July 2020 issue

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

The first technical paper, Tracking the deployment of TLS 1.3 on the Web: A story of experimentation and centralization, by Ralph Holz and his colleagues, deals with Transport Layer Security (TLS) 1.3, a redesign of the Web’s most important security protocol. TLS 1.3 was standardized in August 2018 after a four year-long, unprecedented design process involving many cryptographers and industry stakeholders. In their work, the authors track deployment, uptake, and use of TLS 1.3 from the early design phase until well over a year after standardization.

The second technical paper, Does Domain Name Encryption Increase Users’ Privacy?, by Martino Trevisan and colleagues, is on a topic related to the first technical paper. This work shows that DNS over HTTP (DoH) does not offer the privacy protection that many assume. For the purposes of reproducibility, the authors provide the data used under NDA with the institution owning the data. The authors also share config files and ML environment details in the interest of promoting replicability in other environments.

Our third paper, Using Application Layer Banner Data to Automatically Identify IoT Devices, by Talha Javed and his colleagues, is of the “repeatable technical papers” type, which are technical contributions that provide their artefacts, e.g., software, datasets. This paper attempts to replicate a Usenix Security 2018 paper. It describes the efforts of the authors at re-implementing the solution described in the Usenix Security paper, especially the challenges encountered when authors of the original paper are unwilling to respond to requests for artefacts. We hope it will encourage additional reproducibility studies.

The fourth paper, Towards Declarative Self-Adapting Buffer Management, by Pavel Chuprikov and his colleagues, introduces a novel machine learning based approach to buffer management. The idea is to provide a queue management infrastructure that automatically adapts to traffic changes and identifies the policy that is hypothetically best suited for current traffic patterns. The authors adopt a multi-armed bandits model, and given that different objectives and assumptions lead to different bandit algorithms, they discuss and explore the design space while providing an experimental evaluation that validates their recommendations. The authors provide a GitHub repository that allows for the reproducibility of their result through the NS-2 simulator.

The fifth paper, also our second paper in the new education series, Open Educational Resources for Computer Networking, by Olivier Bonaventure and his colleagues, describes an effort to create an online, interactive textbook for computer networking. What distinguishes this textbook from traditional ones is that it not only is it free and available for anyone in the world to use, but also, it is also interactive. Therefore, this goes way beyond what a textbook usually offers: it is an interactive learning platform for computer networking. The authors here report on about ten years of experience with it, that led to some interesting experiences and lessons learned.

Then, we have two editorial notes. The first, Lessons Learned Organizing the PAM 2020 Virtual Conference, by Chris Misa and his colleagues, reports on the experience from the organizing committee of the 2020 edition of the Passive and Active Measurement (PAM) conference, that took place as a virtual event. It provides important lessons learned for future conferences that decide to go for a virtual event. The second editorial note, Update on ACM SIGCOMM CCR reviewing process: making the review process more open, by the whole CCR editorial board, aims to inform the SIGCOMM community on the reviewing process in place currently at CCR, and to share our plans to make CCR a more open and welcoming venue, adding more value to the SIGCOMM community.

I hope that you will enjoy reading this new issue and welcome comments and suggestions on CCR Online (https: //ccronline.sigcomm.org) or by email at ccr-editor at sigcomm.org.

The April 2020 Issue

SIGCOMM Computer Communication Review (CCR) is produced by a group of members of our community that spend time to prepare the newsletter that you read every quarter. Olivier Bonaventure served as editor during the last four years and his term is now over. It is my pleasure to now serve the community as the editor of CCR. As Olivier and other editors in the past did, we’ll probably adjust the newsletter to the evolving needs of the community. A first change is the introduction of a new Education series led by Matthew Caesar, our new SIGCOMM Education Director. This series will be part of every issue of CCR, and will contain different types of contributions, not only technical papers as in the current issue, but also position papers (that promote discussion through a defensible opinion on a topic), studies (describing research questions, methods, and results), experience reports (that describe an approach with a reflection on why it did/did not work), and approach reports (that describe a technical approach with enough detail for adoption by others).

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

The first technical paper, RIPE IPmap Active Geolocation: Mechanism and Performance Evaluation, by Ben Du and his colleagues, introduces the research community to the IPmap single-radius engine and evaluates its effectiveness against commercial geolocation databases.

It is often believed that traffic engineering changes are rather infrequent. In the second paper, Path Persistence in the Cloud: A Study of the Effects of Inter-Region Traffic Engineering in a Large Cloud Provider’s Network, Waleed Reda and his colleagues reveal the high frequency of traffic engineering activity within a large cloud provider’s network.

In the third paper, The Web is Still Small After More Than a Decade, Nguyen Phong Hoang and his colleagues revisit some of the decade-old studies on web presence and co-location.

The fourth paper, a repeatable paper originated in the IMC reproducibility track, An Artifact Evaluation of NDP, by Noa Zilberman, provides an analysis of NDP (New Data centre protocol). NDP was first presented at ACM SIGCOMM 2017 (best paper award) and proposes a novel data centre transport architecture. In this paper, the author builds the analysis of the artefact proposed by the original authors of NDP, showing how it is possible to carry out research and build new results on previous work done by other fellow researchers.

The Low Latency, Low Loss, Scalable throughput (L4S) architecture addresses this problem by combining scalable congestion control such as DCTCP and TCP Prague with early congestion signalling from the network. In our fifth technical paper, Validating the Sharing Behavior and Latency Characteristics of the L4S Architecture, Dejene Boru Oljira and his colleagues validate some of the experimental result(s) reported in the previous works that demonstrate the co-existence of scalable and classic congestion controls and its low-latency service.

The sixth paper, also our very first paper in the new education series, An Open Platform to Teach How the Internet Practically Works, by Thomas Holterbach and his colleagues, describes a software infrastructure that can be used to teach about how the Internet works. The platform presented by the authors aims to be a much smaller, yet a representative copy of the Internet. The paper’s description and evaluation are focused on technical aspects of the design, but as a teaching tool, it may be more helpful to describe more about pedagogical issues.

Then, we have three very different editorial notes. The first, Workshop on Internet Economics (WIE 2019) report, by kc Klaffy and David Clark, reports on the 2019 interdisciplinary Workshop on Internet Economics (WIE). The second, strongly related to the fourth technical paper, deals with reproducibility. In Thoughts about Artifact Badging, Noa Zilberman and Andrew Moore illustrate that the current badging scheme may not identify limitations of architecture, implementation, or evaluation. Our last editorial note is a comment on a past editorial, “Datacenter Congestion Control: Identifying what is essential and making it practical” by Aisha Mushtaq, et al., from our July 2019 issue. This comment, authored by James Roberts, disputes that shortest remaining processing time (SRPT the crucial factor in achieving good flow completion time (FCT) performance in datacenter networks.

Steve Uhlig — CCR Editor

A Retrospective on Campus Network Traffic Monitoring

Martin Arlitt, Mehdi Karamollahi, Carey Williamson

Abstract

On April 1, 2023 we stopped monitoring the traffic on our campus Internet link, nearly 20 years to the day since we first started doing so. During these two decades, we faced a vast array of issues that affected the collection, storage, analysis and backup of our monitoring data. In this paper we share some of our experiences, so that future networking researchers have an opportunity to learn from our successes as well as our many mistakes and misfortunes.

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Report of 2021 DINRG Workshop on Centralization in the Internet

Christian Huitema, Geoff Huston, Dirk Kutscher, Lixia Zhang

Abstract

The Internet Research Task Force (IRTF) Research Group on Decentralizing the Internet (DINRG) hosted a workshop on Centralization in the Internet on June 3, 2021. The workshop focused on painting a broad-brush landscape of the Internet centralization problem space: its starting point, its driving force, together with an articulation on what can and should be done.

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Recent Trends on Privacy-Preserving Technologies under Standardization at the IETF

Pratyush Dikshit, Jayasree Sengupta, Vaibhav Bajpai

Abstract

End-users are concerned about protecting the privacy of their sensitive personal data that are generated while working on information systems. This extends to both the data they actively provide including personal identification in exchange for products and services as well as its related metadata such as unnecessary access to their location. This is when certain privacy-preserving technologies come into a place where Internet Engineering Task Force (IETF) plays a major role in incorporating such technologies at the fundamental level. Thus, this paper offers an overview of the privacy-preserving mechanisms for layer 3 (i.e. IP) and above that are currently under standardization at the IETF. This includes encrypted DNS at layer 5 classified as DNS-over-TLS (DoT), DNS-over-HTTPS (DoH), and DNS-over-QUIC (DoQ) where the underlying technologies like QUIC belong to layer 4. Followed by that, we discuss Privacy Pass Protocol and its application in generating Private Access Tokens and Passkeys to replace passwords for authentication at the application layer (i.e. end-user devices). Lastly, to protect user privacy at the IP level, Private Relays and MASQUE are discussed. This aims to make designers, implementers, and users of the Internet aware of privacy-related design choices.

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Measuring Broadband America: A Retrospective on Origins, Achievements, and Challenges

Eric W. Burger, Padma Krishnaswamy, Henning Schulzrinne

Abstract

The “Measuring Broadband America” program, run by the United States Federal Communications Commission (FCC), continually measures and releases data on the performance of consumer broadband access networks in the US. This paper presents a retrospective on the program, from its beginnings in 2010 to the present. It also reviews the underlying measurement approaches, philosophies, distinguishing features, and lessons learned over the program’s duration thus far. We focus on fixed broadband access since it is the program component with the longest history. We also discuss future directions and challenges.

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Vulnerability Disclosure Considered Stressful

Giovane C. M. Moura , John Heidemann

Abstract

Vulnerability disclosure is a widely recognized practice in the software industry, but there is a lack of literature detailing the firsthand experiences of researchers who have gone through the process. This work aims to bridge that gap by sharing our personal experience of accidentally discovering a DNS vulnerability and navigating the vulnerability disclosure process for the first time. We document our mistakes and highlight the important lessons we learned, such as the fact that public disclosure can be effective but can also be more time-consuming and emotionally taxing than anticipated. Additionally, we discuss the ethical considerations and potential consequences that may arise during each step of the disclosure process. Lastly, drawing from our own experiences, we identify and discuss issues with the current disclosure process and propose recommendations for its improvement. Our ultimate aim is to provide valuable insights to fellow researchers who may encounter similar challenges in the future and contribute to the enhancement of the overall disclosure process for the benefit of the wider community.

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Who Squats IPv4 Addresses?

Loqman Salamatian, Todd Arnold, Ítalo Cunha, Jiangchen Zhu, Yunfan Zhang, Ethan Katz-Bassett, Matt Calder

Abstract

To mitigate IPv4 exhaustion, IPv6 provides expanded address space, and NAT allows a single public IPv4 address to suffice for many devices assigned private IPv4 address space. Even though NAT has greatly extended the shelf-life of IPv4, some networks need more private IPv4 space than what is officially allocated by IANA due to their size and/or network management practices. Some of these networks resort to using squat space, a term the network operations community uses for large public IPv4 address blocks allocated to organizations but historically never announced to the Internet. While squatting of IP addresses is an open secret, it introduces ethical, legal, and technical problems. In this work we examine billions of traceroutes to identify thousands of organizations squatting. We examine how they are using it and what happened when the US Department of Defense suddenly started announcing what had traditionally been squat space. In addition to shining light on a dirty secret of operational practices, our paper shows that squatting distorts common Internet measurement methodologies, which we argue have to be re-examined to account for squat space.

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The Slow Path Needs an Accelerator Too!

Annus Zulfiqar, Ben Pfaff, William Tu, Gianni Antichi, Muhammad Shahbaz

Abstract

Packet-processing data planes have been continuously enhanced in performance over the last few years to the point that, nowadays, they are increasingly implemented in hardware (i.e., in SmartNICs and programmable switches). However, little attention is given to the slow path residing between the data plane and the control plane, as it is not typically considered performance-critical. In this paper, we show that the slow path is set to become a new key bottleneck in Software-Defined Networks (SDNs). This is due to the growth in physical network bandwidth (200 Gbps is becoming common in data centers) and topological complexity (e.g., virtual switches now span hundreds of physical machines). We present our vision of a new Domain Specific Accelerator (DSA) for the slow path at the end host that sits between the hardware-offloaded data plane and the logically-centralized control plane. We discuss open problems in this domain and call on the networking community to creatively address this emerging issue.

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P4RROT: Generating P4 Code for the Application Layer

Csaba Györgyi, Sándor Laki, Stefan Schmid

Abstract

Throughput and latency critical applications could often benefit of performing computations close to the client. To enable this, distributed computing paradigms such as edge computing have recently emerged. However, with the advent of programmable data planes, computations cannot only be performed by servers but they can be offloaded to network switches. Languages like P4 enable to flexibly reprogram the entire packet processing pipeline. Though these devices promise high throughput and ultra-low response times, implementing application-layer tasks in the data plane programming language P4 is still challenging for an application developer who is not familiar with networking domain. In this paper, we first identify and examine obstacles and pain points one can experience when offloading server-based computations to the network. Then we present P4rrot, a code generator (in form of a library) which allows to overcome these limitations by providing a user-friendly API to describe computations to be offloaded. After discussing the design choices behind P4rrot, we introduce our proof-of-concept implementation for two P4 targets: Netronome SmartNIC and BMv2. To demonstrate the applicability of P4rrot, we investigate case studies in the context of publish-subscribe sensor data processing and real-time data streaming, supporting, in particular, MQTT-SN and MoldUDP packets.

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Comparing User Space and In-Kernel Packet Processing for Edge Data Centers

Federico Parola, Roberto Procopio, Roberto Querio, Fulvio Risso

Abstract

Telecommunication operators are massively moving their network functions in small data centers at the edge of the network, which are becoming increasingly common. However, the high performance provided by commonly used technologies for data plane processing such as DPDK, based on kernel-bypass primitives, comes at the cost of rigid resource partitioning. This is unsuitable for edge data centers, in which efficiency demands both general-purpose applications and data-plane telco workloads to be executed on the same (shared) physical machines. In this respect, eBPF/XDP looks a more appealing solution, thanks to its capability to process packets in the kernel, achieving a higher level of integration with non-data plane applications albeit with lower performance than DPDK. In this paper we leverage the recent introduction of AF_XDP, an XDP-based technology that allows to efficiently steer packets in user space, to provide a thorough comparison of user space vs in-kernel packet processing in typical scenarios of a data center at the edge of the network. Our results provide useful insights on how to select and combine these technologies in order to improve overall throughput and optimize resource usage.

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