Content
a) Internet Control Plane and Software-Defined Networks: The Internet has evolved in recent years into a conceptual two layer architecture, where the control protocols constitute the Control Plane and the basic OSI layer protocols such as IP and the link layer constitute the Data Plane. In practice, the Control Plane protocols use the Data Plane protocols for distribution and mainly run over the same network as the Data Plane, but the conceptual separation is convenient for clarifying thinking about how the Internet works. In this course, we will explore the Control Plane protocols in different routing domains: the wide area network, the data center, and the wireless network. After a short review of the Internet architecture, the IP and link layer, and Software-defined Networking (SDN) we will take up the basics of IP routing and look at routing in the wide area network through the routing protocols RIP, OSPF, and BGP, and discuss how operators use MPLS for traffic engineering. Then we will switch to data center networks, and see how overlay/virtual networks as well as SDNs solve the fundamental problems. Finally, we will focus on wireless networks, specifically access point-based WiFi and the modern LTE/Evolved Packet core network for cellular.
b) „Internet Security": As common utilization of the Internet broadens, the threat from malicious programs and Users increases. To counteract this development during the design of new applications and technologies, we will try to identify and discuss the different attacks and threats (worms, viruses, denial of service). Based on that countermeasures (e.g., firewalls, network intrusion detection/prevention systems, scanners) are introduced and the challenges they are facing are explained. Besides active security tools, secure protocols (e.g., SSL, Kerberos, TLS, VPN, IPsec, WLAN Security) key management approaches and the security of different Internet services (e.g. E-Mail, SSH, VoIP, Network Storage) will be analyzed.
c) The lecture „Evaluation and Measurement of Networked Systems" deals with the following questions: How to set up an experiment to evaluate the correctness and performane of networked and distributed systems? What is the difference between simulations, experiments and formal analysis of networked systems, what are the pros/cons? How to make experiments reproducible? How to reproduce existing experiments? How to conduct measurements in the Internet and other real-world netowrks such as social networks or payment channel p2p networks? How does Internet traffic look like? Are there some characteristic properties? How and where is it possible to improve the Internet, and how can those improvements be tested? How can the previous questions be addressed, and what technical challenges does one face while monitoring? How can data privacy be ensured? Is there something to bear in mind when analyzing such measurements in a statistical manner? Is it possible to generate realistic traffic based on statistical characteristics?
During the seminar „Network Architectures" students acquire scientific knowledge on a small topic on their own, prepare it as a paper, and give a talk on what they learned. Dealing with recent original scientific literature as well as practice and preparation of professional talks are the key benefits for the students. The successful completion of the seminar enables the participants to understand recent, complex and professional literature and to summarize the work. The participation in the seminar includes continuous attendance and active participation, an accepted seminar paper, and its presentation.
The seminar is offered once every term in one of the following variants:
Focus Measurement:
This seminar deals with recent findings and scientific research papers concerning evaluation of networked and distributed systems, reproducability of scientific experiments and Internet measurements. In general these topics are also about measuring and analyzing special characteristics (e.g., throughput, delay, jitter, RTTs, topology) of Internet traffic.
Focus Routing:
This seminar deals with recent findings and scientific research papers concerning Internet routing. Topics range from improvement of routing algorithms over topology detection and emulation to traffic engineering or secure routing, includig payment channel networks as well as peer-to-peer (e.g. Tor) and wireless networks.
Focus Security:
Communication networks such as the Internet, enterprise networks, datacenter networks, or wireless networks, have become a crtitical infrastructure of our digital society. Accordingly, the networks need to meet stringent dependability and security requirements.
Network security is hence crucial and revolves around the policies, processes and practices adopted to prevent, detect and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources.
The goal of this seminar is to get an understanding of the state-of-the-art technology used by both attackers and defenders of networks. To this end, we will critically discuss recent scientific publications in this area, review open-source implementations, and study whether existing methodologies and evaluations can be reproduced. The seminar hence will consist of discussions, presentations and hands-on and research components.