Author Archive

CNDS Web Pages 2.0

July 9th, 2012 Comments off

We are in the process of updating our web pages. We aim at making things more consistent and useful for us and the outside world. One of the new features we added is our new calendar, which can be easily imported into other calendar software. We hope this will make it easier to follow events and deadlines. In order to highlight our activities to improve our pages, we switched to a new theme – wordpress makes all of this remarkably easy.


(Word) Cloud Computing

This image shows how the CNDS web pages look like when the content is rendered as a word cloud. This form of “cloud computing” seems to be visually most attractive and it is quite some fun as well.

We used to generate the word cloud image. You can try this online tool easily yourself on other web sites of your personal interest. We found this tool entertaining for a while.




World IPv6 Day @ Jacobs University

June 9th, 2011 Comments off

Graph showing the IPv6 traffic at Jacobs University during the World IPv6 DayYesterday, on June 8th, we enjoyed the World IPv6 Day. Here is how the IPv6 traffic changed during the day (measured on the tunnel connecting Jacobs’ IPv6 network to the German research network). Apparently, some very popular web sites like Google and Facebook turned off IPv6 right after the day again. This is probably not so good news…

For comparison purposes, here is a plot showing all traffic (IPv4 and IPv6)  going in and out of Jacobs University around the World IPv6 Day. This plot seems to indicate that we carried a significant portion of our traffic over IPv6 during the World IPv6 Day. Note that the event took place when most of our undergraduate students had already left our campus.

The plot on the right shows the longer term impact of the IPv6 day. While some  sites apparently turned off IPv6 support once the event was over, there is also good news since our IPv6 traffic remains at significantly higher levels. Obviously some sites used by our users left IPv6 turned on. We will try to keep an eye on this to see whether this is stable over longer terms or increases or decreases over time.


Netconf Light Demo at IETF 80

March 31st, 2011 Comments off

Some of us attended the 80th IETF meeting in Prague and we used the opportunity to demonstrate the NETCONF protocol running on AVR Raven motes (so called class 1 devices). Of course, these devices only support a subset of NETCONF, which we call NETCONF Light. Our goal was to prove that it is possible to implement a workable subset of NETCONF even on very resource constrained devices. On more powerful motes, such as Econotag motes, it should be possible to run an almost complete NETCONF stack.

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PhD Defense Iyad Tumar

Iyad Tumar submitted his PhD thesis a few weeks ago and today was the day of the defense of his thesis. Iyad managed to survive the intense hours of presentation and discussion. It seems the summer is a good period for getting a PhD degree at Jacobs.



AIMS 2010 Best Paper Award

Nikolay Melnikov presented a paper co-authored by Kaloyan Kanev discussing an implementation of our stream-based IP flow record query language. The paper received the AIMS 2010 best paper award.

IEEE Oceans 2010 Climate Change Poster

Anuj Sehgal presented a poster discussing the effects of climate change and anthropogenic ocean acidification on underwater acoustic communications at IEEE Oceans in Sydney and his poster did win the second position in the student poster competition.

Running Vegesack

This Saturday, the running enthusiasts of the Computer Networks and Distributed Systems group did join the first  running competition in 2010, the Vegesacker Citylauf. Our goal was to find out where we stand after the long winter and how we cope with a slightly more challenging trail (four times uphill and downhill). Overall we did pretty well, several minutes of improvement for some of us on the 10km distance!


Center of Advanced Systems Engineering

February 19th, 2010 No comments

A research center called the “Center of Advanced Systems Engineering” is being established at Jacobs University. Our group has been leading this effort during 2009, from the proposal writing through the proposal evaluation phase and up to the formulation of business plans. Since the beginning of 2010, we are now in the implementation phase where many organizational details are being worked out. While this all keeps us very busy, we are convinced that the centers will provide great benefits for research and graduate education at Jacobs University.


Bachelor Thesis Topics 2010

October 12th, 2009 Comments off

Flowy Performance Evaluation and Improvements

Network routers can export information about network flows they have been forwarding. Flow collectors receive and record these flow records for further processing. The CNDS group has designed a stream-based query language to search for patterns in recorded flow datasets. A first prototype implementation called Flowy, mostly written in Python, has just been completed.

The goal of this assignment is to evaluate the performance of Flowy by comparing it to other tools and identifying bottlenecks of the current implementation and perhaps addressing them subsequently.

The qualification required is very good knowledge of Unix system interfaces and strong C / Python programming skills.

Flow Signatures for Popular Applications

Flow records summarize the network traffic seen at a network metering point (usually located in a router, but might be also located in end systems). Our hypothesis is that many popular
applications generate specific flow signatures, due to probing mechanisms to work around firewalls or due to automatic software update mechanisms or user registration features for example. The
goal of this assignment is to take a number of popular applications and to identify their flow signatures. If our hypothesis is correct, we should later be able to identify such applications in larger flow datasets.

The qualification required is an interest in studying in detail the network traffic generated by popular applications and to (reverse) engineer the logic generating the network traffic. Ideally, the
signatures would be simple and only contain significant features. General scripting and strong data analysis skill will be required.

Visualization of Network Flows

The analysis of large network traces and network flow datasets requires tools to visualize properties of the data. Last year, a tool called snam was created to visualize traces. It is implemented in C++ using OpenGL. The goal of the assignment is to extend the tool with additional visualizations.

The qualification required are excellent C++ programming skills and ideally knowledge of OpenGL and an interest in generating a visualization user interface using an agile development approach that meets the requirements of the users of the visualization tool.


6LoWPAN is a protocol layer enabling IPv6 over IEEE 802.15.4 wireless links. This radio technology is popular for low power and resource contrained devices (8/16-bit microcontroller, 4/8 KByte of
RAM). The goal of this assignment is to implement SNMP over 6LoWPAN with a particular focus on how to make such an implementation resource efficient in terms of CPU and memory usage.

This assignment requires very good C programming skills and the interest to learn about coding in embedded operating systems such as Contiki or TinyOS.

Energy Conservation Through Radio Transmit Power Management

Modern low-power radios such as CC2420 allow dynamic setting of transmission power in order to change the transmission range. Higher transmission powers lead to greater ranges, however, using lower transmission powers can enable more spatial reuse of frequencies. Taking this approach may also reduce the energy consumption. Measuring this energy saving through transmit power management could be very useful since it could lead to energy conservation being built in to the MAC protocols.

The purpose of the project is to investigate the state of the art in radio transmit power management for energy conservation purposes. It would also be useful to create a sensor network using TinyOS and/or Contiki to evaluate the effects of such methods on different network setups. Further, evaluating and comparing existing state of the art would be a meaningful result as well. It would also be interesting to evaluate efficiency of such energy conservation mechanisms on different types of broadcast and multi-hop networks.

TCP Congestion Control Measurements

While there is a standard for TCP congestion control, there are meanwhile many non-standard congestion control mechanisms in use on the Internet. The goal of this project is to further develop a tool that can detect the congestion control algorithm of a TCP server through active probing and to do a larger scale experiment over the Interent.

The ideal candidate has good knowledge about TCP and congestion control, good C programming skills, and strong organizational talents needed for carrying out a larger measurement experiment.