Computer Networks


  • Course: Computer Networks (CO20-320301)
  • Semester: Spring 2017
  • Instructor: Jürgen Schönwälder
  • TA: Schmoll, Felix
  • Class: Tuesday, 09:45-11:00, Lecture Hall Research I
  • Class: Wednesday, 08:15-09:30, Lecture Hall Research I
  • Class: Wednesday, 14:15-15:30, Lecture Hall Research I
  • Class: Friday, 11:15-12:30, Lecture Hall Research III
  • Start: 2017-02-03


The course discusses network protocols in some depth in order to enable students to understand the core issues involved in network protocol design. Fundamental algorithms and principles are explained in the context of existing IEEE / Internet protocols in order to demonstrate how they are applied in real-world scenarios. This course is recommended for all students with a strong interest in communication networks and distributed systems.

The course covers topics such as local area networks (IEEE 802), Internet protocols, routing algorithms and protocols, flow and congestion control mechanisms, data representation, application layer protocols, remote procedure calls, network security.


  • Andrew S. Tanenbaum, "Computer Networks", 4th Edition, Prentice Hall, 2002
  • William Stallings, "Data and Computer Communications", 6th Edition, Prentice Hall, 2000
  • Fred Halsall, "Data Communications, Computer Networks and Open Systems", 4th Edition, Addison-Wesley, 1996
  • Christian Huitema, "Routing in the Internet", 2nd Edition, Prentice Hall, 1999
  • William Richard Stevens, "TCP/IP Illustrated Volume 1: The Protocols", Addison Wesley, 1994
  • Douglas Comer, "Internetworking with TCP/IP Volume 1: Principles Protocols, and Architecture", 4th Edition, Prentice Hall, 2000
  • James F. Kurose, Keith W. Ross, "Computer Networking: A Top-Down Approach Featuring the Internet", 3rd Edition, Addison-Wesley 2004
  • Olivier Bonaventure, "Computer Networking: Principles, Protocols and Practice", 2nd Edition, online


Mon (09:45) Wed (08:15) Wed (14:15) Fri (11:15) Topics
2017-02-03 Introduction, Internet Concepts and Principles, Internet Services Today
2017-02-06 2017-02-10 Media Access Control, Cyclic Redundancy Checks, Flow and Congestion Control, OSI 7-Layer Model
2017-02-13 2017-02-17 Local Area Networks (Ethernet, Bridges)
2017-02-20 2017-02-24 Local Area Networks (VLANs, Port Access Control, WLAN)
2017-02-27 2017-03-03 Internet Network Layer (IPv4/IPv6)
2017-03-06 2017-03-10 Internet Routing Protocols (RIP, OSPF, BGP)
2017-03-13 2017-03-17 Internet Routing Protocols (BGP)
2017-03-20 2017-03-24 Internet Transport Layer (UDP/TCP)
2017-03-27 2017-03-31 Firewalls, Network Address Translators
2017-04-03 2017-04-05 2017-04-07 Security at the Network and Transport Layer (IPsec, TLS, SSH)
+2017-04-10 2017-04-14 [Spring Break]
2017-04-17 2017-04-19 2017-04-21 Internet Application Layer (SMTP, IMAP, PGP, S/MIME, DKIM)
2017-05-02 2017-05-05 Internet Application Layer (HTTP, SPDY, FTP)
2017-05-08 2017-05-12 Internet Application Layer (RTP, SDP, SIP)
2017-05-15 Review and Exam Preparation


Date/Due Name Topics
2017-02-10 Quiz #1 fundamental concepts and terminology
2017-02-17 Sheet #1 ping, traceroute, iperf, mininet (,,
2017-02-24 Quiz #2 media access control, cyclic redundancy checks, flow and congestion control, OSI model
2017-03-03 Sheet #2 bridge spanning trees, wireshark (trace.pcap.gz)
2017-03-10 Quiz #3 Internet network layer, IP forwarding, IP over local area networks (Ethernet)
2017-03-19 Sheet #3 IP over UDP tunnel (socket API)
2017-03-24 Quiz #4 IP fragmentation, IPv4 and IPv6, IP routing overview and principles
2017-03-31 Sheet #4 BGP routing simulation (cbgp, p4-topology.cli)
2017-04-07 Quiz #5 Transmission Control Protocol
2017-04-26 Sheet #5 Transmission Control Protocol
2017-04-28 Quiz #6 cryptography, IP layer security, transport layer security
2017-05-12 Sheet #6 domain name system, multicast dns, dns-based service discovery
2017-05-26 Final Exam 12:30-14:30 CNLH (closed book, hand written cheat sheet (one single-sided a4 page or a double-sided a5 page) allowed)


The final grade is made up of the final exam (40 %), biweekly quizzes (30 %) and homework assignments (30 %). It is required to submit the solution for homeworks assignments electronically. Late submissions will not be accepted. Homeworks may need to be defended in an oral interview.

Any programs which have to be written will be evaluated based on the following criteria:

  • correctness including proper handling of error conditions
  • proper use of programming language constructs
  • clarity of the program organization and design
  • readability of the source code and any output produced

Source code must be accompanied with a README providing an overview of the source files and giving instructions how to build the programs. A suitable Makefile is required if the build process involves more than a single source file.

For any questions stated on assignment sheets, quiz sheets, exam sheets or during makeups, we by default expect a reasoning for the answer given, unless explicitely stated otherwise.

The policy on makeup quizzes is the following: There won't be any quiz makeups. If you (a) get an official excuse for a quiz from the registrar's office or (b) approach we well in advance of the quiz with a very good reason for not being able to participate (e.g., because you take a GRE computer science subject test at the day of a quiz), then the weight of the final exam will be increased according to the weight of the quiz you got excused for.