After successful completion of the course, students are able to recognize, understand, analyze and evaluate selected, prototypical network architectures, protocols and network data with a focus on IP-based real-time multimedia and to model and simulate simple communication networks. The theoretical knowledge acquired upon successful completion includes:

• Standardization: recognize and understand the different types of standardization, versioning and numbering of standards in the field of data communication as an absolute prerequisite for finding the relevant standards. Understanding the main differences between normative and informative standards, the advantages and disadvantages of open telecommunication standardization such as IETF or closed standardization such as IEC. Understand the detailed processes of different standardization bodies.
• Statistics: Understanding and analyzing statistics as a basis for qualified decisions regarding technologies, architectures and protocols in the field of telecommunications. 
• Protocols: Understanding, analyzing and evaluating currently used protocols at the transport layer (UDP, TCP as short repetition of CN1 with additional aspects relevant for the lab exercise, SCTP, DCCP, MPTCP, QUIC) and application level (DNS, HTTP, FTP, SMTP, POP3, SIP, RTP, RTCP, WebRTC, etc) as well as the shortcomings of standardization on the way to interoperability.
• Simulation: Remembering and understanding the theoretical and practical basics of modeling and simulation. Evaluate the advantages and disadvantages of discrete and continuous-time simulation and recognize the need for verification and validation. Recall and avoid typical pitfalls and limitations, especially when simulating with other developer's models.
• Measurements: Fundamentals of the IETF IP Performance Metric Framework: understanding the conceptual separation between metric and methodology or various types of delay in the network, evaluating the advantages and disadvantages of various measurement methods (active, passive, hybrid). Understand the concepts of time synchronization. Recall the two predominant protocols in the field of time synchronization (NTP, PTP), remember their underlying concepts and evaluate their advantages and disadvantages.
• Security: accompanying components in all of the above points are the security and risk aspects and attack surfaces of the architectures and protocols as well as possible countermeasures. Understanding, analyzing and evaluating security at all OSI levels of communication, end-to-end vs. hop-by-hop security.

The practical lab exercises as part of the VU provide students with the necessary skills to independently:

• Perform data recording at network level (PCAP files) 
• Filter existing data recordings according to certain criteria and analyze them in detail at protocol level
• Measure and evaluate the essential parameters of multimedia communication and create relevant statistics. Using case studies to identify typical mistakes and pitfalls
• Explore the limits of encryption and decrypt selected TLS-secured transmission for specific applications.
• Efficiently analyze, reconstruct and evaluate unknown network topologies using the methods learned - including the identification of potential uncertainties.
• Model, simulate and measure simple communication networks - as well as analyze, evaluate and explain the behavior and results at different protocol levels.
• Prepare brief, accurate and useful scientific reports

Higher layer communication protocols (above and including transport layer), protocols for multimedia communication, additional transport protocols, network simulation, practical exercises on communication protocols and network analysis.

The CN2 VU plans for SS 2024 on-premise teaching, both for the lecture and for the lab parts (reasons include, among others, the need for energy savings at TU Wien). Although not planned for now, the CN2 concept and infrastructure allows to switch both, the CN2 lecture and lab, in parts or entirely, to distance learning in the case of emergency measures.

Theory part: On-site lecture part based on slides, a questionnaire is offered as support for learning. Minimum score at final written exam is prerequisite for attending the lab part. Details to be provided during preliminary discussion.

Lab part: Solving of assignments in the CN2 lab in teams of two supported by automated verification of result correctness. Writing of scientifically sound reports, oral examination of lab part (focus: knowledge and comprehension).

First class and preliminary discussion: Tue, 5.3.2023 at 9:00 a.m. (sharp). 

The CN2 preliminary discussion is scheduled for the first lecture unit on March 5th 2023.

• Lecture is scheduled for 2 hours on Tue and 2 hours on Wed until end of April (4 lecture hours per week).
• Laboratory: starts at the beginning of May til end of semester, all Tuesdays, 9:00-12:00 (exception: lab scheduled for Whitsunday Tuesday (vacation) is shifted to the following Wednesday, 9:00-12:00).

Contact address for questions concerning CN2 lecture, lab, or administration:  cn2vu@tuwien.ac.at

For SS 2024 the following rules and terms apply to CN2 lecture content, lab assignments and examination method (Status 31.01.2024):

• The lecture part is read between beginning of March and end of April, lecture slides will be made available. Questions concerning the lecture content can be asked during lecture, in the forum or by email. 

• The lecture closes with a written lecture examination (planned: Tuesday, April 30th 2024), registration via TISS starting mid of April, details in TISS and during the lecture.

• Knowledge of the theory part, confirmed by a positive grade on the lecture examination (at least 50% of score) is prerequisite for attending the lab part of the VU. Not passing the lecture part results in a negative grade for the VU CN2 for this semester. 

• The laboratory part is done in groups of 2 students in the CN2 lab and includes three to four assignments that must be solved and submitted together with a report that must comply to formal requirements. Registration for the lab groups and grading uses TUWEL and will start after the lecture exam has been graded. The score of the lab part is composed of the score on the reports and the score of the oral final lab examination.

• Lecture and lab score contribute equal share to the final grade. Positive score on each, lecture and lab part, is a condition for passing the CN2 VU.

Summary: Written lecture examination, practical laboratory, submission and reports, oral laboratory examination.

Detailed discussion during first CN2 lecture (preliminary discussion). 

Registration required for administrative purposes, planned capacity 42 participants (limit for lab participants because of available Lab PCs).

Laboratory group registration is mandatory and handled separately (by TUWEL) few days after passing the lecture examination.

Theoretical knowledge of Communication Networks 1 lecture content required, in particular Internet basics, protocols (IP, UDP, TCP) and network architectures. Basic programming knowledge required (C++ for NS3 simulation), practical experience with Linux and Wireshark is helpful for the laboratory part.