2019 summer internship at IIJ Innovation Institute's Research Laboratory, Tokyo, Japan

(Last updated: 2018-12-05)

Please check the FAQ section if you have any questions before contacting us.


IIJ Innovation Institute (IIJ-II) Research Laboratory conducts advanced research and technology development on the Internet. The researchers, strongly collaborating with the WIDE Project, were long involved in IPv6 standardization and its BSD stack implementation (KAME project), published well known national Internet traffic measurements and analysis for the last years (MAWI project), endeavored to establish a securer interdomain routing protocol, and to experiment with ecological data centers as well as cloud services.

We are looking for motivated interns who can work with us to accelerate our projects by researching problems, proposing solutions, implementing tools, making various simulations, and so on. By joining us, you can get high quality experience in our research laboratory, can communiate with forefront researchers, have time to discuss with other qualified interns, which will be all benefit to your future carrier plan.

Table of Contents

Compensation and Working Environment

IIJ-II will pay its interns a competitive wage and provide a comfortable research environment with abundant opportunities to gain Internet focused R&D experience.

  • Wage: 250,000JPY/Month (social security expenses and taxes will be subtracted depending on your work contracts)
  • Travel expense is provided
  • Location: Tokyo, Japan
  • Period: 2 months (negotiable depending on the schedule of your Univ.)
  • Accommodation is provided if it is difficult to commute
  • Insurance: Workers' accident compensation insurance (Travel and off-time accident insurance are not covered, we strongly suggest you to prepare them by yourself)

Administrative Details

  • Candidates should be university students (university registration holding for the duration of the internship) with a strong motivation toward research. See project details for the technical expertise required for a specific project.
  • Summer internship for a duration of 2 months in IIJ-II Reasearch Laboratory.
  • To apply for an intern position, send the following documents to internship@iij.ad.jp.
    • ・CV
    • ・A cover letter explaining your interest in the job
    • ・The project name you are interested in
      If available, please send the following documents as well.
    • ・A letter of recommendation
    • ・Your recent published papers
    We will hold face-to-face or remote interviews with applicants before taking a final decision.
  • The deadline for applications is January, 31st, 2019 at 23:59 PST.
    Applications will be reviewed on a rolling basis. It is in the candidate's best interest to apply early. We will begin to schedule interviews in January. We encourage candidates to apply early. Candidates will be notified by the end of February at the latest.
  • If you have any questions, please send a message to internship@iij.ad.jp.

Available Projects

Traffic Measurement and Data Analysis


It is essential for IIJ to understand recent trends in customer traffic.

We will provide an internship student an opportunity to work on a small measurement project, possibly using real-world datasets from IIJ's services, in order to provide practical feedback to IIJ's services.

Possible topics are:

  • development of traffic visualization tools (e.g., for multi-dimensional traffic time-series or for video streaming quality)
  • development of algorithms to provide compact summary information of large-scale traffic data
  • analysis of video streaming traffic behaviors (e.g., differences in video segment fetching strategies)
  • modeling and simulation of network traffic
  • development of monitoring tools for large-scale measurement platforms (e.g. detect outages or identify physical topology from traceroute datasets)
  • the mining of big data, such as the detection and correlation of control and data plane events


We are looking for a graduate student for a two-month-long full-time internship. Candidates should have good skills in computer networking, UNIX systems, and programming as well as oral and written communication skills in English.

For data analysis, skills in machine learning techniques and knowledge of statistics are also required.

To complete a project in two months, a candidate should have substantial experiences in the selected research topic.

Host Researchers

Library Operating System

With the name of specialization, various academic and open source projects invented different shape of network stacks and operating systems. While the specializations avoiding generalization tax solve specific problems of network stack, those are often coupled with the downgraded features due to the specializations, which are hard to recover because the feature richness usually comes with the incremental growth of operating systems.

As a result, there are still serious problems of conventional network stack and library operating systems (or userspace network stacks):

  • network stack ossification (hard to introduce new features), lack of personality
  • lack of generality, resulting no legacy application support
  • simply waste of time (if it is implemented from scratch)

The primary goal of this project is 1) to alleviate the current issue of network stacks, and 2) to retain the feature-richness of the current operating systems by morphing a monolithic kernel into an anykernel implementation (a.k.a. library operating system). The concept of library operating system is not new but it is emerging to address current issues on operating system and network stack.

The objective of this project is to design and develop an implementation of library operating system, Linux Kernel Library (or LKL), to solve aforementioned issues of current operating system.

Possible topics (but not limited to) are:

  • supporting general applications with feature-rich network stack
  • benchmark studies with the implemented software to understand the bottlenecks (incl. comparison with alternatives)
  • container runtime integration
  • fast data plane for virtual network functions with LKL


We are looking for graduate students who have the following knowledge and skills.

  • Knowledge of computer science and networking technology (or equivalent)
  • Skills of system programmings in C
  • Knowledge and/or experience of Linux kernel development
  • Knowledge and/or experience of network performance benchmarks

Host Researcher

One Way Delay


Many algorithms rely on RTTs (Round Trip Times) such as TCP Vegas, TCP for computing its retransmission timeout. Most likely these algorithms could perform better if they had access to the One Way Delay (OWD, also referred to as 'One way latency' or 'One Trip Time') with a better precision than just assuming they are equal to RTT/2. The knowledge of OWDs should help in several situations:

  • disambiguate between forward and backward congestion
  • distinguish disjoint paths based on their forward and backward latencies
  • better scheduling in multipath protocols

OWD is a difficult metric to obtain as it requires time synchronization between the two peers. Available solutions to measure it are either hardware appliances or active solutions such as OWAMP (https://github.com/perfsonar/owamp). Recently it has become possible to plot TCP OWDs with mptcpanalyzer too.
Possible topics are followings,

  • study of TCP one way delays with mptcpanalyzer
  • to investigate the potential gain (throughput/security) for a transport protocol such as TCP, MPTCP, QUIC, etc
  • Identification of shared bottlenecks across flows based on OWDs (M. S. Kim, T. Kim, Y. Shin, S. S. Lam, et E. J. Powers, « A Wavelet-Based Approach to Detect Shared Congestion »)
  • OWD based scheduler for MPTCP on the The Onion Router (TOR) network


We are looking for graduate students who have the following knowledge and skills.

  • Knowledge of computer science and networking technology (or equivalent)
  • C/python (/haskell) programming skills
  • Knowledge and/or experience of Linux kernel development
  • Knowledge and/or experience of network performance benchmarks

Host Researchers

SDN IXP Switching Fabric


The objective of the internship is to provide interns with opportunities to develop, and enhance Internet eXchange switching Fabric with SDN OpenFlow.

Among the possible topics are

  • Developing management tools for SDN Internet eXchange
  • SDN Internet eXchange scalability measurement and development
  • OpenFlow hardware evaluations
  • Study SDN solution for ensuring IXPs operation

The intern will receive support and feedback from IIJ Research Laboratory and a range of external research collaborators along the way.


We are looking for a graduate student in Computer Science or Electrical Engineering to complete a two month full-time internship. Candidates should be competent in computer networking, UNIX systems, Python programming and Software Defined Networking concept. Knowledge of OpenFlow, FAUCET controller and IP routing protocols BGP would be a plus. In addition to the above, candidates should have strong practical and problem-solving skills, the ability to independently produce high quality work, and good English oral and written communication skills.

Host Researchers

Internet Health Report


The Internet Health Report (IHR) leverages data collected by large measurement platforms (e.g. RIPE Atlas, RIS, and RouteViews) to automatically pinpoint connectivity issues in remote networks (https://ihr.iijlab.net/). IHR is looking for talented students and skilled programmers to develop new analysis tools and improve the usability of existing tools. This is a great opportunity for students to work with our large datasets and develop practical and open source tools for network operators, researchers, and Internet users.

Internships for the Internet Health Report are supported by the RIPE NCC Community Projects Fund.

Possible topics include:

  • Front-end development: Visualization of IHR results (experience in Javascript required)
  • Back-end development: Near-real time data analysis (experience in python required)
  • Development of monitoring tools for large-scale measurement platforms (e.g. monitoring latencies or identify physical topology from traceroutes)
  • Analysis or applications of IHR results


We are looking for student/developper for a two-month-long full-time internship starting in June or July. Candidates should have good programming skills (Python or Javascript), and experience with data analysis tools, knowledge in computer networking is also required. Candidate should have good oral and written communication skills in English.

Host Researcher

Messages from Alumni

Marc Anthony Warrior (Year 2017)

You can't go wrong with an IIJ-II internship. If you're on the fence about applying, just do it. The location is amazing (we stayed in the middle of Tokyo, walking distance from the office), the lab community is very welcoming (on most days we ate lunch together), and all of the logistical complexities are completely taken care of (to echo the past intern messages, thanks Kitamura-san!).

I thoroughly enjoyed my experience. It was really pleasant working with Romain and Randy, who began meeting with me via video stream several months before the internship so I could hit the ground running upon arrival. I highly recommend this program if you have the opportunity to apply. It's an excellent research opportunity and a great way to spend a summer.

Simone Ferlin (Year 2017)

I am truly thankful to have been selected to take part in IIJ's summer internship program, although I was almost finished with my PhD. Nevertheless, the internship was an excellent opportunity for me to grow in different ways: I learned new tools and a new research topic and I appreciated that everybody, including the other interns Cristina, Hoang and Marc, was so attentive and approachable.

My topic was about creating a framework to analyze MAWI traffic traces from daily captures between 2001 and 2017 with some known open-source DPI tools. Our goal was to inspect these traces, understand the traffic development over the years in terms of application types and traffic volume, but also observe how these tools perform with the emergence of new applications and encrypted traffic, e.g. HTTPS and QUIC. We worked together for just few weeks, but I was very well assisted as I would be already part of the team - thank you Romain and Kenjiro!

The practicalities of moving to Tokyo were impeccably managed by IIJ: From the visa, flights and accommodation to other formalities after our arrival, everything went smoothly. Because of this, I could make the most of the two months in Tokyo. The accommodation, the office location, the lunch breaks with interesting discussions, Kenjiro, Romain and Keiichi careful restaurants choices and menu explanation, Naoko's assistance and everybody in the lab that took from their time to talk to me - I do cherish your hospitality and patience!

The reason I applied to come to IIJ was a recommendation from an ex-intern, and I would like to keep this cycle alive recommending the internship program further to any young student or researcher. IIJ was an amazing host with very interesting research topics and Japan has an amazing rich culture - you will be always learning something new! The bad part: The two months will be definitely too short!

Hoang Tran (Year 2017)

I had my internship at IIJ-II in 2017 summer. IIJ offered me everything I need to fulfill on obtaining the Visa, how to travel, preparing the accommodation and other issues. My big thank to Naoko-san.

On the research aspect, I worked with Kazuhiko on implementing a new HTTP extension in Chromium browser, which is quite new for me. With his knowledge and experiences, he gave me many insightful advices and hints to fulfill my work. I also had a chance to work and discuss with top experts even outside IIJ in different fields.

Not only that, everyone is so nice and fun that the time was so comfortable, helping me to keep good balance between working and enjoying Japanese lifestyle. People will offer you all basic knowledge and suggestions about Japanese food, traditions, festivals... so do not worry if you cannot speak any Japanese word. Of course, it will be a big plus if you learn some before the travel.

My summer time at IIJ was both a great chance for me to improve my research career and an amazing life experience in a great country. And I believe that will be true for you.

Past Members

Year 2018

  • Andreas Guillot, Strasbourg University, France
  • Francois Michel, Université catholique de Louvain, Belgium
  • Shinyoung Cho, Stonybrook University, U.S.A.

Year 2017

  • Cristina Georgiana Opriceana, Polytechnic University of Bucharest, Romania
  • Marc Anthony Warrior, Northwestern University, U.S.A.
  • Simone Ferlin, University of Oslo / Simula, Norway
  • Hoang Tran, Université catholique de Louvain, Belgium

Year 2016

  • Anant Shah, Colorado State University, U.S.A.
  • Argrios Tasiopoulos, University College London, United Kingdom
  • Julien Gamba, University of Strasbourg, France
  • Răzvan Certezeanu, Imperial College London, United Kingdom
  • Stefano Tracà, Massachusetts Insitute of Technology, U.S.A.

Year 2015

  • Alessandro Puccetti, University of Pisa, Italy
  • Daniel Gröber, Leopold-Franzens-Universität Innsbruck, Austria
  • Kenichi Takagiwa, Keio University, Japan
  • Lachlan Kang, The University of Adelaide, Australia
  • Mijung Kim, Stony Brook, Korea
  • Minoru Kanatsu, Osaka University, Japan

Year 2014

  • Daniele Iamartino, Politecnico di Milano, Italy
  • Gaëtan Briot, Université catholique de Louvain, Belgium
  • Tao Peng, University of Trento, Italy
  • Thomas Holterbach, University of Strasbourg, France

Year 2013

  • David Hauweele, Université de Mons, Belgium
  • Yaser Jararweh, Jordan University of Science and Technology, Jordan
  • Hyoyoung Lim, Nagoya University, Japan
  • Doudou Fall, Nara Institute Science and Technology, Japan

Year 2012

  • Andra Lutu, University Carlos III Madrid, Spain
  • David Lebrun, Université catholique de Louvain, Belgium
  • Hirokazu Hasegawa, Nagoya University, Japan
  • Julien Beaudaux, University of Strasbourg, France
  • Nam Dang, Tokyo Institute of Technology, Japan
  • Zachary Bischof, Northwestern University, U.S.A.

Frequently Asked Questions

General information

When will the application be open?

The summer internship application will be open at the beginning of December every year.

How long is the summer internship program?

The program is for 2 months.

What are the start and end dates for the program?

Interns are able to select either from July 1st to August 31st or August 1st to September 30th. However, it is negotiable depending on the schedule of your university.

Can I extend the internship program?

No, this summer internship program is only for 2 months.


Do I need to obtain a visa?

Yes, you will obtain a 3 month Designated Activities visa.

What are the required documents for obtaining visa?

Our admin staff will contact with you regarding the documents once the duration of your program is fixed.

What are the procedures for obtaining the visa?

IIJ-II will submit the required documents to Tokyo Immigration Office to obtain a certificate of eligibility for your visa.

When the certificate is issued, we will post it to you. After you receive the certificate, please go to the Japanese Embassy or consulate in your country to obtain the visa with your passport as soon as possible.

How long will it take the certificate of eligibility to be issued?

It will usually take about 1.5 to 2 months.


Where can I stay during the internship?

IIJ-II will provide a furnished apartment near the office for those who come from far places. Interns usually stay near Kanda Station in Tokyo. Please note that the accommodation is subject to change depending on the availability.

When can I get the detailed information regarding the accommodation?

IIJ-II will inform you of the details about 3 weeks before your arrival.

Flight ticket

Will IIJ-II pay for my flight?


When can I get the details of my flight?

IIJ-II will arrange the flight ticket after the certificate of eligibility is issued.

I would like to fly from France and fly back to US. Could IIJ-II provide the whole flight tickets?

No, we will provide a round trip ticket only.

Other information staying in Japan

Will travel insurance be provided by IIJ-II?

No, IIJ-II will not provide the insurance. You must make your own arrangements to join a travel insurance plan before you leave for Japan. We recommend that you have travel insurance which also covers flight delays, lost baggage etc.

How can I receive my salary? Do you transfer to my overseas account?

We will pay you in cash. We will not transfer your salary to your overseas account.

When is the pay day?

The pay day is on 25th every month, so you will need some money for day to day expenses until this date.

Can I do some sightseeing after the internship is finished?

The visa is only for the internship, not sightseeing, therefore we would not recommend it. Still, it is possible to arrange your return flight within a week after the last working day if you fix your itinerary beforehand. Note that IIJ-II cannot provide any support once your internship is over so that you need to take full responsibility for your extended stay. Also, you need to leave the apartment the day after the end of the program.

I have some additional questions about Summer Internship Program. Who can I contact?

Please contact internship@iij.ad.jp.