CN214 Computer Networking: Invention & Course Synopsis

• Lecture 1 - CN214 - Computer Networking

Invention & Early Networking

• Initial networking methods were too complicated for practical use.
• Complex calculations like FFT (1966) and hardware limitations (1974) hindered early networking.
• There was no support for mobility in communication (CelNet in 1979)..

Course Synopsis

• The course explores Network & Internet concepts.
• Topics include Delay, Loss, Latency, and Throughput.
• The Shannon & Nyquist theorem will be covered.
• Application layer protocols: HTTP, FTP, SMTP, POP3, DNS, P2P
• Transport Layer: UDP, TCP
• Includes congestion and error control
• IPv4 and IPv6
• Subnetting & Supernetting will be covered.
• Routing protocols: Distance vector, Link-State, RIP, OSPF, and BGP
• Data Link layer, covering media access, VLANs, and error detection & correction.

Course Outcomes

• Students will learn to define computer network layering models.
• Students will describe TCP/IP model protocols and main functions of the 5 Layers
• Students will compare different protocols in each layer of the TCP/IP model.
• Performance of TCP/IP model protocols will be analyzed.
• Learn network protocol internals, using packet analyzer.

Textbook and References

• The textbook for the course is "Computer Networking: A Top-Down Approach, 6th edition" by Kurose and Ross
• A reference book is "Data Communications and Networking, 4th edition" by Forouzan.

Course Structure: Chapters

• Chapter 1: Computer Networks and the Internet
• Chapter 2: Application Layer
• Chapter 3: Transport Layer (UDP & TCP)
• Chapter 4: The Network Layer
• Chapter 5: The Link Layer: Links, Access Networks, and LANs
• Yellow colored topics will be covered in the Mid Term Exam.
• Green colored topics will be covered in the Final Exam.

Mid Term Exam Details

• The mid-term exam will be held on 19/10/2023 (Thursday).
• The exam time is from 12:00 to 13:00.
• The syllabus includes Chapters 1, 2, and 3, focusing on Introduction, Application Layer, and Transport Layer: UDP.
• Question types include True/False, Multiple Choice, Short Questions, and Mathematical Questions.
• Quiz 1 will be used as a reference for the exam.

Course Schedule Overview

• Week 1: Introduction & Network Parameter
• Week 2: Network Layering Model
• Week 3: Application Layer (Assignment 1 Assigned)
• Week 4: Application Layer: FTP & Email (Quiz 1)
• Week 5: Application Layer: DNS and P2P
• Week 6: Transport Layer
• Week 7: Transport Layer Protocol: UDP
• Week 8: Transport Layer Protocol: TCP
• Week 9: TCP Flow & Congestion Control (Mid Term Exam)
• Week 10: Network Layer: Switching
• Week 11: IP Address & Subnetting
• Week 12: NAT & IP Protocol
• Week 13: IPv6 (Assignment 2 Assigned, Quiz 2)
• Week 15: Data Link Layer: Protocol & Error Control
• Week 16: Data Link Layer: Access
• Week 17: Revision & LAB Final Exam (LAB Final Exam)
• Week 18: Semester Final Exam
• Week 19: Semester Final Exam

Assessment Breakdown

• Quizzes (2): 10%
• Mid Term Examination (1): 25%
• Final Examination: 40%
• Lab Experiments: 25%
• Total: 100%

Lab Assessment Distribution

• Experiments are worth 5%
• Quizzes: 5%
• Mid Term Examination: 5%
• The Final Examination is 10% Total 25%

Office Hours

• Sunday: 11 AM – 12 PM
• Tuesday: 11 AM – 12 PM
• Wednesday: 11 AM – 12 PM

Communication

• A communication link connects a sender and receiver.
• Electromagnetic waves propagate between them carrying data.
• There is a transmission delay.

Key Definitions

• Message: Information to be communicated.
• Medium: The physical path the message travels.
• Sender: The device sending the data message.
• Receiver: The device that receives the message.
• Protocol: The set of rules governing data communication.

Network and Internet

• The internet facilitates community and business.
• A network consists of devices (nodes) connected by communication links.
• A node is a device that can send/receive data.
• IoT/IoE devices can also send/receive data.
• The most specific and public network is the Internet.

Internet Usage Statistics (2023 Estimates)

• Global internet usage statistics and population data were provided for 2023.
• The world population is 7,932,791,734, with 5,385,798,406 internet users at a 67.9% penetration rate
• Asia has the highest internet usage.
• Africa has: 1,394,588,547 Population (2022 Est.) with 601,940,784 internet users
• Asia has: 4,352,169,960 Population (2022 Est.) with 2,916,890,209 internet users
• Europe has: 837,472,045 Population (2022 Est.) with 747,214,734 internet users

Internet: Nuts and Bolts View

• The internet can be viewed as "Nuts-and-Bolts", which represents the basic infrastructure.
• It can be also seen as a networking infrastructure providing service for distributed applications.
• Nuts and bolts terminology refers to its fundamental hardware and software components.
• It connects billions of computing devices.
• Traditional devices include PCs, laptops, servers, and smartphones
• Non-traditional computing devices like TVs and web-cams are connecting to the Internet.
• The connecting devices are called end systems or hosts.
• End systems connect to the internet through communication links
• Links use fiber, copper, radio, or satellite to communicate.
• Transmission rates are measured by bandwidth.
• Packet switches forward data in chunks.
• Routers and switches are examples.
• The internet is a "network of networks".

Internet as FUN Appliances

• The Internet can be seen as a collection of "FUN appliances".
• Web-enabled toasters are an example and can function as weather forecasters
• Tweet-a-watts monitor energy consumption.
• Internet refrigerators provide connectivity in the kitchen.
• Slingboxes allow remote control of cable TV.
• IP picture frames display digital photos using internet connections
• There are Internet phones for communication.

Basic Networking Concepts

• Nodes connect with communication links using routers and switches.
• Data is segmented into packets for network transmission.
• A network route is the path traversed by packets.
• Communication links transmit data at a certain transmission rate (bits/second or bps).

Internet & Protocols

• The Internet is a "network of networks".
• Protocols govern sending and receiving messages.
• Examples include TCP, IP, HTTP, Skype and 802.11.
• Internet standards are developed in these protocols
• They are formalized through Request for Comments (RFC) open to the Internet Engineering Task Force (IETF).

The Internet: A Service Perspective

• The internet provides services to applications.
• Applications include VoIP, web, email, and e-commerce.
• Programming interfaces facilitate application connectivity.
• Hooks allow apps to "connect" to the Internet.
• Service options are analogous to the postal service.

What are Protocols?

• Internet protocols are rules/regulations for data-sending over the internet, such as TCP, IP, and HTTP.
• Human protocols involve human rules to communication.

Human vs Network Protocols

• Human protocols involve natural language and human interaction.
• Network protocols involve machines, communication activity, format, order messages, and action taken between network entities

Network Structures

• The network edge consists of hosts, clients, and servers often in data centers.
• Access networks and physical media include wired and wireless communication links.
• The network core consists of interconnected routers and networks of networks.

Access Network and Physical Media

• End systems connect to the edge router through residential, institutional, and mobile nets.
• Residential access networks include DSL, TV cable, fiber, dial-up, and satellite.
• Institutional networks are schools and companies using Ethernet and WiFi.
• An important consideration is bandwidth (bits per second) and whether the connection is shared or dedicated.

Access Networks (DSL, Cable, Fiber)

• DSL (Digital Subscriber Line) uses existing telephone lines
• Data goes to internet and voice goes on telephone net
• Up to 2.5 Mbps upstream and 24 Mbps downstream.
• Cable networks use frequency division multiplexing.
• HFC (Hybrid Fiber Coax) is asymmetric and has increased transfer rates.
• Fiber to the Home has higher transmission rates and also carries TV and Phone signal
• Home networks combine wireless access points, a router with firewall, and wired Ethernet.

Enterprise Networks and Ethernet

• Enterprise networks are large business environments .
• Enterprise networks include users and locations and are supported and have centralized control.
• Ethernet is typically used at 10 Mbps / 100Mbps /1 Gbps / 10 Gbps transmission rates.

Wireless Access Networks

• Shared wireless access networks connect to the router.
• Wireless LANs operate in buildings while Wireless access operates in telco.

Physical Media

• A bit propagates between transmitter and receiver pairs.
• Unguided media: signals propagate freely
• Twisted pair (TP): Category 5 (100 Mbps, 1 Gpbs Ethernet ) and Category 6 (10 Gbps).
• Coaxial cable has copper wires and high-speed operation
• Fiber optic cable carries light pulses and has a low error rate.
• Radio links have electromagnetic spectrum and various propagation environment effects

Internet: Network Interconnections

• End systems connect to Internet (ISPs)
• There are residential, company and universities
• Access ISPs interconnected and complex
• Interconnected ISPs allow two hosts to send packets

Internet: Network Scaling

• Connecting each Access ISP to every other Access ISP does not scale due to O(N^2) connections
• A global transit ISP connects "Customer" and "Provider" in agreement
• Competitors connected and need an "Internet exchange point"
• Regional networks may arise and connect access to ISPS

Internet Service Providers

• ISPs can scale using content providers.
• Commercial ISPs (e.g., Level 3, Sprint, AT&T, NTT)
• At the center: are well-connected large networks