Author Archives: Steve Uhlig

P4Pi: P4 on Raspberry Pi for networking education

Sándor Laki, Radostin Stoyanov, Dávid Kis, Robert Soulé, Péter Vörös, Noa Zilberman

Abstract

High level, network programming languages, like P4, enable students to gain hands-on experience in the structure of a switch or router. Students can implement the packet processing pipeline themselves, without prior knowledge of circuit design. However, when choosing a P4 programmable target for use in the classroom, instructors face a lack of options. On the one hand, software solutions, such as the behavioral model (BMv2) switch, are overly simplified and offer low performance. On the other hand, existing hardware solutions are closed source and expensive.

In this paper, we present P4Pi, a new, low-cost, open-source hardware platform intended for networking education. P4Pi allows students to design and deploy P4-based network devices using the Raspberry Pi board, which has a price tag of less than many academic textbooks. We describe the high-level design of the P4Pi platform, offer some suggestions for how P4Pi could be used in the classroom, and present some additional use-cases for applications and functionality that could be developed using P4Pi.

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The graph neural networking challenge: a worldwide competition for education in AI/ML for networks

José Suárez-Varela, Miquel Ferriol-Galmés, Albert López, Paul Almasan, Guillermo Bernárdez, David Pujol-Perich, Krzysztof Rusek, Loïck Bonniot, Christoph Neumann, François Schnitzler, François Taïani, Martin Happ, Christian Maier, Jia Lei Du, Matthias Herlich, Peter Dorfinger, Nick Vincent Hainke, Stefan Venz, Johannes Wegener, Henrike Wissing, Bo Wu, Shihan Xiao, Pere Barlet-Ros, Albert Cabellos-Aparicio

Abstract

During the last decade, Machine Learning (ML) has increasingly become a hot topic in the field of Computer Networks and is expected to be gradually adopted for a plethora of control, monitoring and management tasks in real-world deployments. This poses the need to count on new generations of students, researchers and practitioners with a solid background in ML applied to networks. During 2020, the International Telecommunication Union (ITU) has organized the “ITU AI/ML in 5G challenge”, an open global competition that has introduced to a broad audience some of the current main challenges in ML for networks. This large-scale initiative has gathered 23 different challenges proposed by network operators, equipment manufacturers and academia, and has attracted a total of 1300+ participants from 60+ countries. This paper narrates our experience organizing one of the proposed challenges: the “Graph Neural Networking Challenge 2020”. We describe the problem presented to participants, the tools and resources provided, some organization aspects and participation statistics, an outline of the top-3 awarded solutions, and a summary with some lessons learned during all this journey. As a result, this challenge leaves a curated set of educational resources openly available to anyone interested in the topic.

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NemFi: record-and-replay to emulate WiFi

Abhishek kumar Mishra, Sara Ayoubi, Giulio Grassi, Renata Teixeira

Abstract

This paper presents NemFi: a trace-driven WiFi emulator. NemFi is a record-and-replay emulator that captures traces representing real WiFi conditions, and later replay these traces to reproduce the same conditions. In this paper, we demonstrate that the state-of-the-art emulator that was developed for cellular links cannot emulate WiFi conditions. We identify the three key differences that must be addressed to enable accurate WiFi record-and-replay: WiFi packet losses, medium-access control, and frame aggregation. We then extend the existing cellular network emulator to support WiFi record-and-replay. We evaluate the performance of NemFi via repeated experimentation across different WiFi conditions and for three different types of applications: speed-test, file download, and video streaming. Our experimental results demonstrate that average application performance over NemFi and real WiFi links is similar (with less than 3 percent difference).

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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.

Great educators in computer networking: Bruce Davie

Matthew Caesar, Bruce Davie

Abstract

This interview is part of a series on Great Educators in Computer Networking, where we interview some of the most impactful and skilled educators in our field. Here, we interviewed Australian Bruce Davie, the self-described computer scientist/engineer/runner/cyclist, who agreed to talk to us about his thoughts on computer networking education, his role in it, his thoughts about the big ideas in our field, and how the pandemic is changing our work. Bruce has over 30 years of industry experience and is well known for a broad spectrum of educational initiatives such as co-authoring several textbooks, as well as his contributions to many networking standards and technologies, including IP quality of service, network virtualization, software defined networking, and more.

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SatNetLab: A call to arms for the next global Internet testbed

Ankit Singla

Abstract

The space industry is moving rapidly towards offering low-latency and high-bandwidth global Internet coverage using low Earth orbit satellites. Such networks represent “one giant leap” in Internet infrastructure, both in their goals and the underlying technology. Due to their unique characteristics, they open up new opportunities, and pose new research challenges. I thus lay out a case for networking researchers to collaboratively undertake the construction of SatNetLab, a research platform that enables experimentation across upcoming satellite-based networks.

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Workshop on Internet Economics (WIE 2020) Final Report

kc claffy, David Clark

Abstract

On 16-17 December 2020, CAIDA hosted the 11th interdisciplinary Workshop on Internet Economics (WIE) in a virtual Zoom conference. This year our goal was to gather feedback from researchers on their experiences using CAIDA’s data for economics or policy research. We invited all researchers who reported use of CAIDA data in these disciplines. We discussed their successes and challenges of using the data, and how CAIDA could help these fields via Internet measurement and data curation. To avoid Zoom fatigue, we had a conversation-focused rather than presentation-focused workshop. Research topics we discussed included: Internet data for macroeconomics; connectivity and its effect on economic interdependence; effects of the EU’s new GDPR on internet interconnection; measuring corporate cyber risk; measuring work-from-home trends; measuring the economic value of open source software; and more generally how to best support evidence-based policymaking.

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The Netivus Manifesto: Making Collaborative Network Management Easier for the Rest of Us

Joseph Severini, Radhika Niranjan Mysore, Vyas Sekar, Sujata Banerjee, Michael K. Reiter

Abstract

We study operational issues faced by Small and Medium Enterprise (SME) network owners and find that SME network management practices have stagnated over the past decade, despite many recent advances in network management. Many of these advances target hyperscalers and ISPs and cannot be directly applied to SME networks that are operated with vastly different constraints. In our work, we outline these constraints and explain how they impact challenges around debugging, namely: representing, reproducing, and remediating network problems. This article takes a fresh look at these challenges in the light of SME practices around collaborative debugging and presents a roadmap aimed to help resolve SME operational issues quickly.

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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.

Revitalizing the Public Internet By Making it Extensible

Hari Balakrishnan, Sujata Banerjee, Israel Cidon, David Culler, Deborah Estrin, Ethan Katz-Bassett, Arvind Krishnamurthy, Murphy McCauley, Nick McKeown, Aurojit Panda, Sylvia Ratnasamy, Jennifer Rexford, Michael Schapira, Scott Shenker, Ion Stoica, David Tennenhouse, Amin Vahdat, Ellen Zegura

Abstract

There is now a significant and growing functional gap between the public Internet, whose basic architecture has remained unchanged for several decades, and a new generation of more sophisticated private networks. To address this increasing divergence of functionality and overcome the Internet’s architectural stagnation, we argue for the creation of an Extensible Internet (EI) that supports in-network services that go beyond best-effort packet delivery. To gain experience with this approach, we hope to soon deploy both an experimental version (for researchers) and a prototype version (for early adopters) of EI. In the longer term, making the Internet extensible will require a community to initiate and oversee the effort; this paper is the first step in creating such a community.

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