ITT351: Computer Networks (Spring 2026)

Class Timings: Monday, Wednesday (Section A: 11:30-12:20 pm and Section B: 12:20-1:10 pm) 

  Tuesday (Section B: 11:30-12:20 pm and Section A: 12:20-1:10 pm) 

Venue: PF3

Piazza page: ITT351/home 

Course Overview

In this course, we will cover the basic concepts and details of network implementation. In particular, we will have an in-depth study of various TCP/IP model layers via a bottom-up approach.

Course Outline

• UNIT I - INTRODUCTION: History and development of computer networks, networks topologies. Layering and protocols.

• UNIT II - PHYSICAL LAYER: Different types of transmission media, transmission errors: attenuation, noise. Encoding (NRZ, NRZI, Manchester, 4B/5B, etc.).

• UNIT III - DATA LINK LAYER AND SWITCHING: MAC Layer: Aloha, CSMA, CSMA/CD, CSMA/CA protocols. Data Link Layer: Error detection (Parity, CRC), Sliding Window, Stop and Wait protocols. Framing, HDLC. Switching Theory: Circuit Switching, Message Switching, Packet Switching.

• UNIT IV - NETWORK LAYER: Network layer: Internet Protocol, IPv6, ARP, DHCP, ICMP, Routing algorithms: Distance vector, Link state, Metrics, Inter-domain routing. Subnetting, Classless addressing, Network Address Translation.

• UNIT V - TRANSPORT LAYER: UDP, TCP. Connection establishment and termination, sliding window revisited, flow and congestion control, timers, retransmission, TCP extensions, etc.

• UNIT VI - APPLICATION LAYER: Session, Presentation, and Application Layers. Examples: DNS, SMTP, IMAP, HTTP, etc.

References: We will refer to multiple books and lectures over the duration of this course some of them are as follows:

• Behrouz A. Forouzan, Data communications and Networking [BAF]

• JF Kurose, KW Ross, Computer Networking: A Top-Down Approach [KR]

• Larry Peterson and Bruce Davie, Computer Networks, A Systems Approach [PD]

• William Stallings, Data & Computer Communications [WS]

• Sandip Chakraborty, Soumya Kanti Ghosh, Computer Networks and Internet Protocol (NPTEL Course) [NPTEL]

• Aaron Balchunas, CCNA Guides [AB]

• Ajit Pal, Data Communications (NPTEL Course) [AP-NPTEL]

Grading Policy:

• Major exam - 50%

• Mid-Term exam - 26%

• Assignment-based quizzes - 8%

• General quizzes - 8%

• Tutorials - 8%

Tutorials (To be submitted on Gradescope) 

1. Tut 1 (Access control)

Quizzes 

1. Quiz 1 (Assignment-based): Error detection and correction techniques. Date: 25 Feb

Here are the topics we covered in the class and the reference material we used.

1. Lec 1 (Feb 11): General introduction to the course, course outcomes, policies, and motivation. Recap of OSI model and TCP/IP model.

2. Lec 2 (Feb 16): Introduction to access control, motivation, random access protocols, pure Aloha. (Main source: Chapter 12 [BAF]) (Extra Source: Lec 25-27 [AP-NPTEL])

3. Lec 3 (Feb 17): Pure and slotted Aloha analysis: throughput formula, maximum throughput. (Main source: Chapter 12 [BAF]) (Extra Source: Lec 25-27 [AP-NPTEL])

4. Lec 4 (Feb 18): Motivation and working of CSMA, different persistent methods: 1-persistent, nonpersistent, p-persistent, motivation for CSMA/CD, minimum frame size, CSMA/CD algorithm, and its performance. (Main source: Chapter 12 [BAF]) (Extra Source: Lec 25-27 [AP-NPTEL])

5. Lec 5 (Feb 23): CSMA/CA: need and motivation, collision avoidance strategies, Hidden and exposed node problem, RTS-CTS solution, NAV.  (Main source: Chapter 12 [BAF]) (Extra Source: Lec 25-27 [AP-NPTEL])

6. Lec 6 (Feb 24): Controlled access methods - reservation, polling access method and token passing with examples. (Main source: Chapter 12 [BAF]) (Extra Source: Lec 25-27 [AP-NPTEL])

7. Lec 7 (Feb 25): Channelization methods: FDMA, TDMA, CDMA - basic idea, working, properties of codes, generation of codes using Walsh tables. (Main source: Chapter 12 [BAF]) (Extra Source: Lec 25-27 [AP-NPTEL])