Inhalt des Dokuments
Topics for the Seminar on Internet Measurement, SoSe 2012
Topics for the seminar on Internet Measurement
(SoSe 2012) .
Themenvorschläge für das Seminar über Internet Measurement (SoSe 2012) .
- Unmasking the Growing UDP Traffic in a Campus Network
- Geolocating IP Addresses in Cellular Data Networks
- Xunlei: Peer-Assisted Download Acceleration on a Massive Scale
- Behavior of DNS’ Top Talkers, a .com/.net View
- Analyzing Facebook Privacy Settings: User Expectations vs. Reality
- I Know Where You are and What You are Sharing: Exploiting P2P Communications to Invade Users’ Privacy
- OFLOPS: An Open Framework for OpenFlow Switch Evaluation
Unmasking the Growing UDP Traffic in a Campus Network
Student/Bearbeiter: Andrii Soloviov; Supervisor/Betreuer: Stefan Schmid 
Transmission control protocol (TCP) has been the dominating protocol for Internet traffic for the past decades. Most network research based on traffic analysis (e.g., router buffer sizing and traffic classification) has been conducted assuming the dominance of TCP over other protocols. However, a few recent traffic statistics are showing a sign of significant UDP traffic growth at various points of Internet links . In this paper we show that the UDP traffic has grown significantly in recent years on our campus network; we have observed a 46-fold increase in volume (from 0.47% to 22.0% of total bytes) in the past four years. The trace collected in 2011 shows that the grown volume is not from a small number of UDP hosts nor port numbers. In addition, the recent UDP flows are not sent at constant bit rate (CBR) for most cases, and the aggregated traffic shows burstiness close to TCP traffic.
- Changhyun Lee, DK Lee, and Sue Moon. Unmasking the Growing UDP Traffic in a Campus Network , Passive and Active Measurements Conference (PAM) 2012.
Geolocating IP Addresses in Cellular Data Networks
Student/Bearbeiter: Julius Bachnick; Supervisor/Betreuer: Ruben Merz 
Smartphones connected to cellular networks are increasingly being used to access Internet-based services. Using data collected from smartphones running a popular location-based application, we examine IP address allocation in cellular data networks, with emphasis on understanding the applicability of IP-based geolocation techniques. Our dataset has GPS-based location data for approximately 29,000 cellular network assigned IP addresses in 50 different countries. Using this dataset, we provide insights into the global deployment of cellular networks. For instance, we find that Network Address Translation (NAT) is commonplace in cellular networks. We also find several instances of service differentiation with operators assigning public IP addresses to some devices and private IP addresses to other devices. We also evaluate the error of geolocation databases when determining the position of the smartphones, and find that the error is 100km or more for approximately 70% of our measurements. Further, there is potential for errors at the scale of inter-country and inter-continent distances. We believe this dataset may be of value to the research community, and provide a subset of the dataset to the community.
- Sipat Triukose, Sebastien Ardon, Anirban Mahanti, Aaditeshwar Seth. Geolocating IP Addresses in Cellular Data Networks , Passive and Active Measurements Conference (PAM) 2012.
Xunlei: Peer-Assisted Download Acceleration on a Massive Scale
Student/Bearbeiter: Fotouhi Tehrani Pouyan; Supervisor/Betreuer: Oliver Hohlfeld 
We take a close look at Xunlei, an enormously popular download acceleration application in China. Xunlei forms a complex ecosystem, with Xunlei peers extensively interacting with independent HTTP and FTP servers, cyberlockers (such as megaupload and hotfile), the BitTorrent and eDonkey file-sharing systems, as well as with other Xunlei peers. After performing a protocol analysis on Xunlei, we develop a comprehensive measurement infrastructure, enabling us to gain new insights into the scale of content, swarm sizes, and several unique characteristics of the system mechanisms in Xunlei.
- Prithula Dhungel, Keith W. Ross, Moritz Steiner, Ye Tian, Xiaojun Hei. Xunlei: Peer-Assisted Download Acceleration on a Massive Scale , Passive and Active Measurements Conference (PAM) 2012.
Behavior of DNS’ Top Talkers, a .com/.net View
Student/Bearbeiter: Florian Streibelt; Supervisor/Betreuer: Enric Pujol 
This paper provides the first systematic study of DNS data taken from one of the 13 servers for the .com/.net registry. DNS’ generic Top Level Domains (gTLDs) such .com and .net serve resolvers from throughout the Internet and respond to billions of DNS queries every day. This study uses gTLD data to characterize the DNS resolver population and profile DNS query types. The results show a small and relatively stable set of resolvers (i.e. the top-talkers) constitute 90% of the overall traffic. The results provide a basis for understanding for this critical Internet service, insights on typical resolver behaviors and the use of IPv6 in DNS, and provides a foundation for further study of DNS behavior.
- Eric Osterweil, Danny McPherson, Steve DiBenedetto, Christos Papadopoulos, and Dan Massey. Behavior of DNS’ Top Talkers, a .com/.net View , Passive and Active Measurements Conference (PAM) 2012.
Analyzing Facebook Privacy Settings: User Expectations vs. Reality
Student/Bearbeiter: Sayed Abdullah Walizai; Supervisor/Betreuer: Carlo Fürst 
The sharing of personal data has emerged as a popular activity over
online social networking sites like Facebook. As a result, the issue
of online social network privacy has received significant attention in
both the research literature and the mainstream media. Our overarching
goal is to improve defaults and provide better tools for managing
privacy, but we are limited by the fact that the full extent of the
privacy problem remains unknown; there is little quantification of the
incidence of incorrect privacy settings or the difficulty users face
when managing their privacy.
In this paper, we focus on measuring the disparity between the desired and actual privacy settings, quantifying the magnitude of the problem of managing privacy. We deploy a survey, implemented as a Facebook application, to 200 Facebook users recruited via Amazon Mechanical Turk. We find that 36% of content remains shared with the default privacy settings. We also find that, overall, privacy settings match users’ expectations only 37% of the time, and when incorrect, almost always expose content to more users than expected. Finally, we explore how our results have potential to assist users in selecting appropriate privacy settings by examining the user-created friend lists. We find that these have significant correlation with the social network, suggesting that information from the social network may be helpful in implementing new tools for managing privacy.
- Yabing Liu, Krishna P. Gummadi, Balachander Krishnamurthy, Alan Mislove. Analyzing Facebook Privacy Settings: User Expectations vs. Reality , Internet Measurement Conference (IMC) 2011.
I Know Where You are and What You are Sharing: Exploiting P2P Communications to Invade Users’ Privacy
Student/Bearbeiter: Eduardo Alfredo Brito Chacon; Supervisor/Betreuer: Benjamin Frank  & Ingmar Poese 
In this paper, we show how to exploit real-time communication applications to determine the IP address of a targeted user. We focus our study on Skype, although other real-time communication applications may have similar privacy issues. We first design a scheme that calls an identified-targeted user inconspicuously to find his IP address, which can be done even if he is behind a NAT. By calling the user periodically, we can then observe the mobility of the user. We show how to scale the scheme to observe the mobility patterns of tens of thousands of users. We also consider the linkability threat, in which the identified user is linked to his Internet usage. We illustrate this threat by combining Skype and BitTorrent to show that it is possible to determine the filesharing usage of identified users. We devise a scheme based on the identification field of the IP datagrams to verify with high accuracy whether the identified user is participating in specific torrents. We conclude that any Internet user can leverage Skype, and potentially other real-time communication systems, to observe the mobility and filesharing us- age of tens of millions of identified users.
- Stevens Le Blond, Chao Zhang, Arnaud Legout, Keith Ross, Walid Dabbous. I Know Where You are and What You are Sharing: Exploiting P2P Communications to Invade Users’ Privacy , Internet Measurement Conference (IMC) 2011.
OFLOPS: An Open Framework for OpenFlow Switch Evaluation
Student/Bearbeiter: Tobias Steinicke; Supervisor/Betreuer: Nadi Sarrar 
Recent efforts in software-defined networks, such as OpenFlow, give
unprecedented access into the forwarding plane of networking
equipment. When building a network based on OpenFlow however, one must
take into account the performance characteristics of particular
OpenFlow switch implementations. In this paper, we present OFLOPS, an
open and generic software framework that permits the development of
tests for OpenFlow-enabled switches, that measure the capabilities and
bottlenecks between the forwarding engine of the switch and the remote
control application. OFLOPS combines hardware instrumentation with an
extensible software framework.
We use OFLOPS to evaluate current OpenFlow switch implementations and make the following observations: (i) The switching performance of flows depends on applied actions and firmware. (ii) Current OpenFlow implementations differ sub- stantially in flow updating rates as well as traffic monitoring capabilities. (iii) Accurate OpenFlow command completion can be observed only through the data plane. These observations are crucial for understanding the applicability of Open- Flow in the context of specific use-cases, which have requirements in terms of forwarding table consistency, flow setup latency, flow space granularity, packet modification types, and/or traffic monitoring abilities.
- Charalampos Rotsos, Nadi Sarrar, Steve Uhlig, Rob Sherwood, and Andrew W. Moore. OFLOPS: An Open Framework for OpenFlow Switch Evaluation , Passive and Active Measurements Conference (PAM) 2012.
Lehre / Teaching, SoSe 2013
- Routerlab (PR) 
- NA: Internet Measurement (SE) 
- Internet Security (VL) 
- Internet Measurement (VL) 
- Internet Routing (VL) 
0432 L 822
Dozent: Anja Feldmann, Stefan Schmid
11.04.2013 bis 12.07.2013
Preparatory Meeting: (possibly) 11 April 2013, 10:00, Auditorium 1 (TEL 20)