Applied Networking Research Workshop at IETF-96

The first ACM, IRTF & ISOC Applied Networking Research Workshop 2016 (ANRW ‘16) was held in co-location with IETF-96 on July 16, 2016, in Berlin. The MAMI project conributed with one full paper and three short papers describing multipath bonding as an use case for MCP, PATHspider’s inital release, as well as the basic structure of MAMI’s Path Transparency Observatory (see ANRW’16 webpage for papers and presentations):

  • Multipath bonding at Layer 3. (Full)
    Maciej Bednarek (ETH Zurich), Guillermo Barrenetxea Kobas (Swisscom), Mirja Kühlewind (ETH Zurich), and Brian Trammell (ETH Zurich).
  • Towards a Multipath TCP Aware Load Balancer. (Short)
    Simon Liénardy (Université de Liège) and Benoit Donnet (Université de Liège).
  • PATHspider: A tool for active measurement of path transparency. (Short)
    Iain R. Learmonth (University of Aberdeen), Brian Trammell (ETH Zurich), Mirja Kuhlewind (ETH Zurich), and Gorry Fairhurst (University of Aberdeen).
  • Towards an Observatory for Network Transparency Research. (Short)
    Stephan Neuhaus (Zürcher Hochschule für Angewandte Wissenschaften), Roman Müntener (Zürcher Hochschule für Angewandte Wissenschaften), Korian Edeline (Université de Liège), Benoit Donnet (Université de Liège), and Elio Gubser (ETH Zurich).

anrw-postersWhile this was a great opertunity to present the work of the MAMI project, there have been a number of very interesting and related papers. To learn more about an extended API for Multipath TCP, multi-homing in IPv6, the effects and cost of Happy-Eyeballs,  and measurement on IPv6 and DSCP usage, check out the ANRW’16 webpage.

Thanks to Lars and Colin for organizing this very interesting and interactive workshop!

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2. MAMI Plenary Meeting in Berlin

The MAMI project held its second technical plenary on July 13-15, 2016, in Berlin. This time also members of the External Advisory Board (EAB) participated. Thanks for your time, fruitful discussions and very valuable input! Also special thanks Joe Hildebrand for providing meeting space in the Cisco openBerlin Innovation Center (as well as the free barista team building event..)!


We started on our first afternoon with an open discussion slot focusing on two main topics of the project: test specifications and Middlebox Cooperation Protocol (MCP) design. While the MAMI project is currently running a number of path transparency tests on the Internet, we decided to also provide a specifications of current and planned tests to enable external parties to run similar measurements on other testbeds. Stay tuned, we will provide further measurement results as well as the specs soon!

Just before the meeting, we released the first PATHspider version “Phidippus audax” (0.9.0). In case you wonder why PATHspider only has six legs, there is a sad story to tell which involves a compression middlebox…


After submitting our first technical deliverable D3.1 on Use Cases and Requirements for MCP, we now enter the actual protocol design phase. We discussed and agreed on the basic mechanisms for signaling from and to middleboxes, as also outlined at the PLUS BoF meeting at IETF96 in the following week (see slides here).

Further, work package 2 on Middlebox Classification and Modelling started this month. This work will be informed by our own middlebox measurements and testing as well as additional tests we plan to run in cooperation with our EAB member Paul Hoffman on the ICANN middlebox testlab.

All in all, we had a very productive and fruitful meeting, including an old-fashioned french dinner, and a great tour of craft breweries in bars throughout Berlin.

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70% of popular Web sites support ECN

One of the primary goals of MAMI’s measurement work is to quantify path transparency in the Internet: how likely a given transport protocol or feature is to work on which paths, and how these features break. Earlier work by MAMI partners ETH and the University of Aberdeen on this topic focused on Explicit Congestion Notification (ECN) in TCP, a feature that allows congestion to be detected without packet loss. Our paper, based on measurements in August and September 2014 and published at PAM 2015, found that 56% of IPv4 and 65% of IPv6 hosts serving the Alexa top million websites would negotiate ECN if the client requested it, which at the time was not the default in any major client operating system. ECN negotiation attempts could lead to connectivity issues and fallback to non-ECN usage for 0.42% of IPv4 and 0.05% of IPv6 servers in the top million.

In the meantime, Apple has added ECN negotiation by default on the client side in developer previews of Mac OS X and iOS, and our patch adding fallback in the case of ECN failure to non-ECN usage, as specified in RFC 3168, has been added to the Linux kernel. The tooling for the 2015 paper is evolving into a generic path impairment measurement tool called PathSpider. So what’s the state of the Alexa top million today?

ecn-trendWe recently ran a measurement from a single vantage point, a DigitalOcean server in Amsterdam, to the set of unique IPv4 and IPv6 addresses serving the top million websites, and found that 432544 of 617873 (70.005%) of IPv4 addresses and 20262 of 24472 (82.797%) IPv6 addresses will negotiate ECN. This continues a trend ETH started observing in 2013, shown here.

The proportion of servers requiring fallback has not changed appreciably: 0.44% of IPv4 and 0.11% of IPv6 servers. This reflects the two different forces at work: ECN support on the server side generally follows the operating system defaults, and web hosting machines generally run a recent Linux, the first operating system with server side ECN on by default. Connectivity problems, however, are often a function of faulty middleboxes, which are more slowly replaced, or firewall rules explicitly disabling ECN traffic for dubious reasons.

Detailed analysis behind this blog post is available here; the raw data it runs on will be made available shortly.

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MAMI was represented at RIPE 72 in Copenhagen with two presentations by ETH. First, Mirja Kühlewind presented a possible application of MAMI’s Middlebox Cooperation Protocol (MCP) in “What if we designed measurement as a first-order service?”, an exploration of what it would take to build Internet measurement on protocol foundations stronger than ping and a collection of ingenious hacks.

Brian Trammell also presented “Internet Path Transparency Measurements using RIPE Atlas”, on MAMI’s use of the RIPE Atlas platform to find differential treatment between UDP and TCP, and the incidence of UDP blocking on access networks. Here, we found about 3% of Atlas probes to be on networks where UDP is severely impaired. More in-depth analysis of this question will appear in an upcoming paper, currently under submission.

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IETF95 was held last week (3-8 April) in Buenos Aires, Argentina, and the MAMI project was out in force. First and foremost, project coordinator Mirja Kühlewind assumed the office of IETF Transport Area Director at the plenary meeting on Wednesday evening.


Congratulations on the yellow dot!

Brian Trammell presented a small research study performed with RIPE Atlas at the Measurement and Analysis for Protocols (MAP) proposed Research Group, on the deployability of UDP encapsulation-based approaches to deploying new transport protocols, as MAMI will explore with its middlebox cooperation protocol (MCP) and flexible transport layer (FTL). He also presented a potential approach to supporting low-latency service signaling using a new IP Differentiated Services codepoint at the “Alternatives to Content Classification for Operator Resource Deployment” (ACCORD) BoF, where explicit cooperation with respect to radio access network were discussed.

The Transport Services (TAPS) working group was interesting as well: our abstract work on decomposing transport protocols into features, to be published shortly, has led to the first concrete proposals on implementation.The NEAT project presented their proposed API for an adaptive transport layer, and MAMI will bring an FTL API proposal to the next meeting in Berlin.


The Limited Use of Remote Keys (LURK) BoF was also of special interest to the project, as key management protocols useful in CDN and operator networks may present a way forward for cooperation with trusted middleboxes. MAMI partner TID is working on an implementation of a key server for LURK, and we’ll be watching continued developments in this space.

Being in Buenos Aires, the project made sure to enjoy the local cuisine (thanks Oscar Gonzalez for local arrangements!)


And in the marketing department, MAMI’s measurement / experimentation / architecture stickers were a big hit.


We’re all back home and mostly recovered from the jet lag, but here are only three months left until the next IETF meeting in Berlin in July. We’ll be hard at work preparing, including a potential Birds of a Feather session to discuss the standardization of approaches like MAMI’s MCP. Watch this space!

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MAMI Promo Tour started

Over the last few weeks, we went around and gave a couple of presentations about the current and planned work in MAMI. Feedback was very positive and we identified more friendly people to work with. If you want to learn more about MAMI (illustrated with some nice and colorful picture), check out the slides on the Publications page. Especially the following presentations will provide you a good overview:

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MAMI Kickoff Meeting in Zürich

The MAMI project held its first plenary meeting at the Networked Systems Group at ETH Zürich this week.


The technical agenda included detailed discussions of measurement tool design, the beginnings of the detailed specification of our Path Transparency Observatory (as initially described in our RAIM paper), and further refinement of the use cases, requirements, and security model for our Middlebox Cooperation Protocol.

The nontechnical agenda included the obligatory-for-Switzerland-in-winter cheese fondue.


We also began technical coordination with two related Horizon 2020 projects with whom we share partners: MONROE is a FIRE testbed we’ll use for measurements as well as middlebox cooperation experiments, and NEAT aims to redesign application-transport interactions in the Internet. We look forward to a productive collaboration with both projects.

In addition, we formally appointed our External Advisory Board: Joe Hildebrand, Paul Hoffman, Dirk Kutscher, Allison Mankin, Szilveszter Nadas, and Dave Plonka. Welcome aboard, and many thanks to our advisors!

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MAMI webpage updated

The MAMI webpages has been updated to now contain more information on the project’s objectives, work package structure as well as standardization efforts.
Also check out our github at

Next thing to do is our first plenary meeting on Feb 8-10 in Zürich. Stay tuned to find further information here on current and planned activities after the meeting!

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Dagstuhl Seminar on Global Internet Measurement

Mirja Kühlewind (ETH) and Brian Trammell (ETH) from the MAMI project kicked off the new year by participating in a seminar at Schloss Dagstuhl on Global Measurement Practice and Experience. Dagstuhl seminars are always thought provoking, but in addition to informing the design of MAMI’s forthcoming Internet Path Transparency Observatory, two specific initiatives started there that we hope will ease the creation of measurement studies like the one we’re undertaking: first, a common platform for active measurement platforms on small hardware (e.g. Raspberry Pi); and second, a cooperative, Internet-measurement-focused “storage cloud” for reliable distribution of archival data generated by such platforms. Watch this space for future developments.

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Welcome to MAMI

MAMI (“Measurement and Architecture for a Middleboxed Internet”) is a European Commission Horizon 2020 funded research project. Our consortium is made up of seven European universities, research laboratories, and industrial partners. We aim to rearchitect the Internet to allow explicit cooperation between endpoints and middleboxes, restoring the promise and innovation potential of the original end-to-end architecture of the Internet while enabling appropriate in-network services to ease management and scalability of ever more demanding applications.

A central tussle in today’s Internet is that between the desire for privacy, which requires strong encryption to protect, and the need to efficiently manage network traffic. Current approaches to traffic management typically require access to plaintext and application payload, which is fundamentally incompatible with the privacy goal. By replacing implicit cooperation (e.g. middleboxes which assume they have access to traffic and understand its semantics) with explicit cooperation (endpoint and application signaling to middleboxes and vice-versa), we aim to break this tussle.

MAMI has two broad goals:

  • empirical research to develop what kinds of middleboxes perform what kinds of manipulations on what paths, in order to understand the present Internet: both the extent and variety of in-network services as well as the degrees of freedom for incremental deployment of new protocols; and
  • development of a Middlebox Cooperation Protocol (MCP) that would enable explicit cooperation between endpoints and middleboxes, transport innovation, and ubiquitous encryption simultaneously.

MAMI will officially start in January 2016, but we’re already hard at work:

  • the How Ossified is the Protocol Stack? (HOPS) proposed research group within the Internet Research Task Force (IRTF) met at IETF 92 in Prague and will meet again at IETF 93 in Yokohama; the RG provides a forum for exchanging information on measurements of middlebox impairment in the Internet and tools for researching it
  • A paper on an initial proposal for the MAMI Middlebox Observatory will be presented at the IRTF/ISOC workshop on Research and Applications of Internet Measurements (RAIM).

Keep an eye on this blog for news about the project as we go forward.

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