A primary concern for operators is to provide access to voice, video and data services via their existing radio access networks, thereby, leveraging the capital already invested in these networks. To achieve carrier-grade quality while preserving flexibility and cost efficiency is a key challenge due to the inherent limitations of wireless mesh networks, namely limited throughput and scalability. The goal of the CARMEN project is to overcome this challenge and realize such a carrier-class mesh network over heterogeneous wireless network technologies.

Within this project, the work will focus on the interface management and implement the following list of commands and functionalities (list represents an overview):

• Responding to queries regarding device properties: These properties include transmit power levels, directionality, available data rates etc. as well as supported events/commands

• Responding to queries regarding the current state: The current values of different parameters (current transmit power level, current transmit rate etc.) should be read and sent to CAMS.

• Setting the values of different parameters: Based on requests forwarded by CAMS, new values are assigned for different parameters (such as setting a new transmit power level)

Further Information: Full project description (PDF)

A primary concern for operators is to provide access to voice, video and data services via their existing radio access networks, thereby, leveraging the capital already invested in these networks. To achieve carrier-grade quality while preserving flexibility and cost efficiency is a key challenge due to the inherent limitations of wireless mesh networks, namely limited throughput and scalability. The goal of the CARMEN project is to overcome this challenge and realize such a carrier-class mesh network over heterogeneous wireless network technologies.

Within this project, the work will focus on creating a messaging interface between a TDMA-based coordinated MAC adaptor and CAMS, which serves as a mediator between upper layer protocols and heterogeneous lower layer technologies.

To this end, the following functionalities need to be implemented (list represents an overview):

• Forwarding CARMEN-specific control messages: These include broadcast messages that carry information about the mesh network, and mesh node registration messages destined to the gateway. The implementation requires extending beacon messages already used by the TDMA MAC protocol to carry mesh specific information.

• Reporting the detected mesh links to CAMS: The receipt of a mesh-specific beacon messages (defined in the previous bullet) must be notified to CAMS.

• Neighbourhood scanning: Reporting the number of neighbours and neighbour statistics to CAMS.

Further Information: Full project description (PDF)

With provisioning of broadband access for mass market, multimedia content is extensively viewed and exchanged over the Internet. Quality of Experience (QoE) aspects, describing the service quality perceived by the user, are vital factors. Creating frameworks for accessing quality degradations in streamed video currently is investigated as a complex multi-layered research topic.

Within this area, the thesis will focus on the packetized transmission of TV content; In IPTV, encoded video and audio data is encapsulated in packets which can get lost (packet loss) in phases of overload or due to transmission failures. In order to compensate packet loss, an IPTV solution will implement a resend mechanism that requests lost packets for a limited amount of time. If a packet cannot be resent within a given time frame, the packet is considered to be lost and causes visual impairments in the decoded image. These impairments will lower the Quality of Experience. Thus, for a model of IPTV quality, the effects of the resend mechanism have to be taken into account.

Further information: PDF

With provisioning of broadband access for mass market, multimedia content is extensively viewed and exchanged over the Internet. Quality of Experience (QoE) aspects, describing the service quality perceived by the user, are vital factors. Creating frameworks for accessing quality degradations in streamed video currently is investigated as a complex multi-layered research topic.

Within this area, the thesis will focus on the packetized transmission of TV content; In IPTV, encoded video and audio data is encapsulated in packets, which can get lost (packet loss) in phases of overload or due to transmission failures. In order to compensate transmission failures, Forward Error Correction (FEC) can be deployed to detect and correct errors. If a packet cannot be repaired, the packet is considered to be lost and causes visual impairments in the decoded image. These impairments will lower the Quality of Experience. Thus, for a model of IPTV quality, the effects of the applied Forward Error Correction scheme have to be taken into account.

Further information: PDF

With provisioning of broadband access for mass market, multimedia content is extensively viewed and exchanged over the Internet. Quality of Experience (QoE) aspects, describing the service quality perceived by the user, are vital factors. Creating frameworks for accessing quality degradations in streamed video currently is investigated as a complex multi-layered research topic.

This thesis will focus on a performance evaluation of existing metrics designed for predicting the image or video quality, respectively. Selected metrics that are not already implemented will have to be implemented. Selected metrics will be applied to an existing database of video sequences. Their performance will be compared with ratings of subjects that have been obtained in previous empirical tests.

Further information: PDF

Scope

The Berlin Open Wireless Lab (BOWL) aims towards building a wireless Testbed in the Area of the TUB Campus. We are using Intel XScale based hardware running the OpenWRT Linux distribution.

Audience/Requirements

The current projects in the BOWL projects are suited best to students who fancy low level programming in the Linux environment. Good knowledge of the Linux platform is required, but the specific hardware or kernel related knowledge can be aquired during the project. Knowledge of OpenWRT helps, but is not required. All software written during the project will be released as OpenSource Software.
There are always several topics available, most of them can be worked on in the scope of a project, or in a Diplom/Master Thesis. Diplom/Master thesis' will require a strong analytical and experimental evaluation of the subject, thus some skills in network measurement and statistics are required.

Topics

Topics come, among others, from the areas of

• Node management: Monitoring, system upgrades, software distribution

• Routing: Wireless routing protocols, client mobility

• Transport Gateways: Proxies, redundant uplinks, Transport and Application Layer bridges

• Service Discovery: Distributed service discovery, smart flooding, DHT based algorithms

• Measurement: Wireless measurement, link layer analysis, self-interference, trace synchronisation and merging

Details:

A detailed list of all projects in this area can be found on the BOWL website

Project description: Click is a modular router architecture that is used for the Berlin Open Wireless Lab (BOWL) mesh network. Thanks to the extensibility of Click, we not only use it for the forwarding of packets on the backbone of the mesh network but also to implement and manage the access point (AP) functionality of our network, or to manage client mobility between access points (AP). Unfortunately, in its current state Click lacks support for WPA and WPA2 authentication and encryption between clients and APs.

Hence, the goal of this project is to implement, test and validate support for WPA and WPA2 authentication and encryption in Click by interfacing Click with hostapd. Hostapd is a user space daemon for access point and authentication servers (http://hostap.epitest.fi/hostapd/). A particular emphasis will be done on validation. There is an extensive list of clients that we want to support: Windows (XP, Vista), OS/X and iPhones, Linux, symbian.

Skills:

• Required: Comfortable with Linux, C++.

• Plus but not required: 802.11 and security knowledge.

Project description: Recently, both the IETF and the Routing Research Group (RRG) of the IRTF have started to explore the possibility to design a new Internet architecture, in order to solve some scalability issues the current architecture is facing. One of the proposed solutions is LISP: Locator/ID Separation Protocol. Such a protocol separates end-host identifiers from the routing locators and uses a tunneling based approach in order to perform packet forwarding. Even if the approach is designed for inter-domain routing, it can provide some benefits in the context of wireless mesh networking, namely in managing clients mobility. The objective of this project is to port the existing OpenLISP implementation on OpenWRT systems and evaluate the features that LISP introduces in a wireless mesh network like BOWL.

Required Skills: A good knowledge of C programming as well as Linux is necessary to carry out the work.

Holger Dreger developed a half-automatic configuration tool for Bro which adjusts a Bro installation to work stable and efficiently for a given network with given hardware. You should evaluate the performance of the configuration tool, i. e., you should develop metrics of how to measure the efficiency of such a tool and then evaluate how good the metrics are fullfilled, e. g., compare to a hand-tuned configuration.

Network packet traces (e.g., from CAIDA) are invaluable for security and performance analysis. Furthermore, they are the foundation of many measurement study. A common tool we employ to analyze packet traces is the Bro Intrusion Detection System (IDS). Bro expects to see both sides of a connection and it expects packets with full application payload. This assumption does not hold for many traces. Often traces contain only the beginning of every packet (i.e., packet headers) and traces also often contain only one side of a connection (N.B. that a lot of traces have some connections with both sides and some connections with only one side).

The tool should be able use pattern matching on the traces to identify applications, it should be able to extract HTTP headers, and it should collect per connection statistics (number of bytes, number of packets). It should be extensible, so that adding other analysis or statistics is easy.

The goal of this thesis is to check whether there are tools that can already do this (e.g., the Snort IDS) If such a program is not found then you should evaluate whether it is easier (better) to adopt Bro to handle such traces or whether it is easier to implement such a tool from scratch. Finally, you should implement this functionality (by changing Bro or by writing a new tool).

Recently, both the IETF and the Routing Research Group (RRG) of the IRTF have started to explore the possibility to design a new Internet architecture, in order to solve some scalability issues the the current architecture is facing. In particular there is a fair amount of activity around the approach based on the separation of the end-systems' addressing space (the identifier) and the routing locators' space. This separation is perceived as the basic component of the Future Internet architecture. Among the pletora of proposals available, the basic need is to evaluate them in order to deeply understand the impact of such change will have on the Internet as we know today. To this end there is the need to develop new evaluation tools and to analyze the current traffic in order to forecast the behaviour of the Future Internet.

Today IP addresses and locations form a single block. It is believed that separating ID's from locators for end-hosts will lead to a more scalable Internet. As its name indicates, the mapping system is in charge of the translation between ID's of Internet hosts and where they are located.

Several proposals for the mapping system have been made so far, many of them based on one particular type of P2P network: Distributed Hash Tables (DHT). DHT's are highly scalable but require a uniform distribution of the content across the overlay, which is not acceptable in the Internet where networks don't trust each other. A better alternative is SkipNet. SkipNet is a P2P overlay that allows to express locality constraints, e.g., which P2P nodes should keep information about the data. SkipNet also seems to bring resilience to disconnections.

The objective of this Diplom or Masters thesis is to evaluate the feasibility of relying on a P2P system called SkipNet, to bring scalability to the core of the Internet. An implementation of SkipNet exists in OMNET++, but will likely need to be adapted and extended for our purposes. Good knowledge of C++ and data structures will be necessary to succesfully achieve the goals of this project.

The RouterLab is the experimental network platform of our group, destined for research as well as for teaching.

In this experimental environment, users typically have root priviledges on their experimental devices. To monitor their usage, e.g., prevent misuse of the devices, and to detect unused reservations, we run several monitoring systems (e.g., Nagios, Cacti, Arpwatch etc.). These should be further extended and improved, and integrated into a centralized cockpit view.

The goal of this project is to develop and deploy an integrated monitoring solution for use in the internal routerlab network. We will evaluate and leverage existent tools, and combine their results into a central view. You should have good background knowledge on network protocols and be interested in network monitoring. For the integration, a bit of experience in web programming (e.g., Ruby On Rails), is useful, but not mandatory.

Currently, the Internet core has all but stopped to evolve (see, e.g., the lacking adapation of DNSSec, IPv6 and DiffServ). Network Virtualization may be a key technology to overcome this Internet Impasse. To implement this concept and manage the resulting virtual networks, a number of different platforms have been proposed around the globe, e.g., Planet-Lab, VINI and EmuLab.

The goal of this project or thesis is to evaluate and compare these platforms from a practical perspective for managing a federated Network Virtualization testbed. For this, you will deploy the platforms in our experimental environment (the Routerlab), and evaluate several management scenarios.

Emergence of new heterogeneous wireless technologies have created means for anytime anywhere networking. However, Quality of Service that can be expected from wireless networking is still limited. This phenomenon has posed new challenges for network operators to maintain certain level of service quality to their users using wireless as a backbone network infrastructure. Furthermore, expectation of users have also continued increasing; for instance, skype and Youtube have become the most popular applications for internet users.
The main goal of the thesis is to investigate the performance of multimedia applications over Wireless network using BOWL and Routerlab Testbed infrastructure in the presense of real and artificial traffic. Experimental results are expected to provide insightin order to improve the performance of multimedia applications over Wireless Networks.

With the emergence of new services and fierce competition among the Internet service providers, focus of researchers is shifted from Quality of Service (QoS) to Quality of Experience (QoE), i.e., quality as perceived by the user. The main goal of this thesis is to create Internet like dynamic conditions in RouterLab testbed and evaluate QoE under various different networking conditions for Voice over IP application. For this purpose a software mechanism ExpAuto will be developed which will ensure automation of experiments in the testbed from a central point along with collection of experiment data. Results of the experiments will be analyzed in order to establish relationships between networking parameters such packet-loss, delay, jitter and user perception.

The Timemachine employs a connection cutoff, that basically only stores the first N bytes of a connection. The goal of this project / thesis is to move the cutoff to kernel space. I. e. to modify the capturing stack of the kernel to include connection cutoff.

This thesis is about identifying common tasks of researchers when dealing with Netflow data, and evaluating the performance of different databases (e.g., SQLite or HDF5) using the test cases.

In this thesis a edonkey Analyzer for Bro will be written. The goal is to be able to parse eDonkey traffic and to figure out, how eDonkey is used.

The RouterLab is the experimental platform of our group, used for research as well as for teaching. It consists of switches, routers (Cisco, Juniper) and Linux PCs. To prevent people from accessing the same device simultaneously, the devices need to be reserved before they are used.

This functionality is provided by the Labtool that offers a commandline interface to create new reservations. Besides, it allows to modify and delete existing reservations and to dump and restore the configurations of routers. Unfortunately, the Labtool in its current state does not follow modern software design principles and therefore is not easy to extend and maintain. Furthermore, we would like to offer the users a Web-based interface that is easy to use and that integrates the numerous commandline options that are currently available.

The goal of this project is to design and implement a modern web-based frontend for the Labtool. You should be interested in applying state-of-the-art object-oriented software design principles and tools to develop a nice Web GUI that is fun to use and easy to extend. Knowledge of Ruby/RubyOnRails, or Python/Django is useful, but not mandatory.

The topic of this work is to extract such a Social Network from real traces, and to analyse it regarding its graph properties and compare it versus the social networks of humans in real life.

Skype is a proprietary communication protocol, mainly used for VoIP telephony. Skype uses a lot of mechanisms to circumvent firewalls and NAT gateways. Furthermore the protocol as well as the proprietary client are encrypted and therefore hard to analyze. Your task is to develop a Bro analyzer for the Skype protocol which detects and classifys (where possible) Skype traffic reliably. Based on this work, you should evaluate the behaviour of Skype traffic on real network traffic.

The goal is to secure DNS via persistent TCP Connections betweeen DNS Servers. Keeping compatibility requires unsecure UDP connections as well, but those can then be limited, thus hindering DoS attacks.

Install and configure nagios on our central server. Evaluate what software is needed on the wireless nodes and prepare packages for this software.

Draft a system to automatically distribute software to OpenWRT nodes. This should include installing new firmware images, or to add or remove ipkgs (OpenWRT's software package format). Use ssh for commands and http to transfer software. This system should contain mechanism to customize the configuration on the individual node (e.g., IP-Address, hostname, …). You should be able to customize

• postinstall scripts

• UCI variables (can be set with a single shell command)

• postinstall extra files.

The purpose of this project is two-fold, first to build a simple Oracle client application and second, to embed the Oracle funtionality in selected P2P file-sharing applications.

The Oracle service has been proposed as a novel ISP-client collaboration paradigm towards efficient formation of P2P overlays. An end-user submits a list of candidate peers to the oracle server. The response of the server is a ranked list based on simple performance heuristics assuming full information about the underlying network.

The task in this thesis are three-fold. First, to enrich the ranking algorithms taking into consideration semi-static metrics such as AS distances, router-level hop distances, access and backbone bandwidths, as well as dynamic metrics such as delays, links and node utilization, available bandwidth and path diversity, among others. Attributes such as ISP routing and traffic engineering policies are also taken into consideration. Second, to study the performance of ranking algorithms under incomplete or un-updated view of the underlying network. Third, to examine ranking algorithms that are resilient to DDoS attacks.