Students will mature a critical view of Internet technologies, their performance implications, and the bottlenecks or possible misconfigurations that can occur. In detail, students will learn: 1. the fundamentals of Internet protocols like IP, TCP, UDP, HTTP, QUIC and DNS, and the way to properly configure them 2. how to configure, troubleshoot and identify network configuration errors like duplicated addresses, misconfigured line cards, implementation bugs, etc. 3. how to properly engineer a “speed test” experiment to measure the performance in Ethernet and Wi-Fi networks 4. the impact of delay and packet loss on the performance of a download, or a video stream application, and of virtualization (Virtual Machines or VMs) or hardware acceleration techniques 5. the proper configuration of routing protocols and the impact of link failures on the network topology 6. the ability to process significant traffic traces and extract information related to performance and troubleshooting issues from real traffic. The ability to apply the gained knowledge will be verified by preparing lab reports and discussing them during an oral examination at the end of the course.

Students must know the protocols and mechanisms normally used on the Internet. Students must have a solid knowledge of LAN protocols (Ethernet IEEE 802.3, Wi-Fi IEEE 802.11, CSMA/CA and CSMA/CD, direct and indirect delivery, LAN interconnections), network (IPv4, IPv6, routing protocols), transport (TCP/UDP) protocols, and application layer protocols (DNS, HTTP, HTTPS, QUIC, multimedia streaming protocols, etc.).

Students will go through the following laboratories: 1. Configuration of hosts in Local Area Networks, IP addresses management, subnetting/supernetting (2 hours) 2. Traffic monitoring using sniffers in LAN: TCP, UDP and HTTP (4 hours) 3. Troubleshooting of local area networks: presence of link failures, duplicated addresses, misconfigured interfaces, etc. (4 hours) 4. Network discovery and security: portscan and netscan using nmap (2 hours) 5. Engineering of “speed test” measurements: a. file transfer throughput in wired networks (6 hours) b. file transfer throughput in Wi-Fi networks (6 hours) c. impact of virtualization (4 hours) d. impact and fairness of TCP and QUIC congestion control algorithms with packet loss and delay (8 hours) 6. Video streaming performance and impact of packet loss and delay (4 hours) 7. Routing configuration: manual routing setup and automatic configuration with OSPF protocol (6 hours) 8. Analysis of traffic traces collected from real networks and development of post-processing tools to extract information out of the raw data (14 hours)

The course is particularly useful for students enrolled in the “Computer Networks”, “Cloud Computing” and “Cybersecurity” tracks of the Computer Engineering Master Degree.

Most of the course will be held in laboratories where students will work in groups and face various experiments. They will work with Linux and the lab PCs, or use their own laptops, preparing and executing the lab experiments. Before each lab session, the instructor will present the fundamentals of protocols, technologies, and tools to recap the involved technologies. At the end of each lab session, the instructor will discuss the results with students to understand and clarify the main takeaway messages and facts.

The teaching material will be made available by the class teacher on the Didattica web portal. The material will guide the students with a description of the lab experiments, reference documentation, and theoretical information. No textbook is available. Students must be familiar with Internet protocols and applications, which can be found for example, in -- A. Pattavina: Internet e Reti: Fondamenti, Pearson, 3a ed., 2022 (in Italian) -- J.F. Kurose, K.W. Ross: Computer Networking: A Top-Down Approach Featuring the Internet, Pearson (in English)

Lecture notes; Lab exercises; Video lectures (current year); Video lectures (previous years);

You can take this exam before attending the course

Exam: Compulsory oral exam; Individual essay; Group essay;

GROUP REPORT During the laboratories, students are required to work in groups of three people. At the end of each lab, each group will have to deliver a written report on the specific topics indicated by the instructor. In total, each group will prepare 6 group reports. Each report must be delivered and uploaded to the teaching portal by a specific deadline. The report will be graded evaluating the result correctness and the completeness of the performed experiments. All students in the group will obtain the same grade, up to a maximum of 27/30. If all other reports are sufficient, students are offered the opportunity to revise at most one report. If some reports are insufficient, students must revise and resubmit them. To be admitted to the oral exam, all reports must be sufficient and ready before the exam application deadline. The group report mark will be valid for all group members and will be valid for two years. INDIVIDUAL REPORT Each student will also prepare an individual report that will be discussed during the oral examination. The instructor will define the topic of the individual report. Students will have to upload the individual report on the teaching portal website before the exam application deadline. EXTRA POINTS by taking part in the discussion during labs During classes and labs, students are invited to answer questions and discuss the results they obtained, gaining up to 2 extra points. ORAL EXAM During the oral exam, each student will be asked to discuss the content of the reports (both group and individual). The oral exam is individual, and students will be asked to answer questions about the course's practical and theoretical parts. The grade for the oral exam must be sufficient to pass the exam, with a minimum of 18/30 and a maximum of 30 cum laude. The final grade will be a weighted average between the evaluations of the group laboratory report (70%) and oral examinations (30%). It is possible to get additional points with specific topic reports or prepare lesson notes to be reused in subsequent years.

In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.