Networking and Internet
Master the architecture of digital communication: from transmission media (Twisted Pair, Coaxial, Fiber, Radio, Satellite) and network hardware (Hubs, Switches, Routers, Gateways) to topologies, TCP/IP stack, MAC vs IP addressing, and modern cyber threat defense.
Evolution of Computer Networking
A computer network is an interconnected collection of autonomous computers and peripherals capable of exchanging data and sharing resources (printers, storage, applications) over communication media guided by a uniform set of rules termed protocols.
Alexander Graham Bell
Invention of the telephone and early Public Switched Telephone Network (PSTN) utilizing circuit switching.
ARPANET
Advanced Research Projects Agency Network by US DoD connecting 4 universities using packet switching.
TCP/IP Protocol Suite
Developed by Vinton Cerf and Robert Kahn, becoming the foundational open networking standard worldwide.
NSFNET & World Wide Web
National Science Foundation high-speed backbone (1984) and Tim Berners-Lee’s invention of WWW at CERN (1989).
5 Fundamental Components of Data Communication
Modes of Data Transmission
Unidirectional Communication
Data travels exclusively in one direction. The sender can only send, and the receiver can only receive.
Examples: Keyboard to CPU, traditional television broadcast, monitor display.
Bidirectional Alternate
Both parties can transmit and receive, but only one direction at a time. The entire channel bandwidth is used during transmission.
Examples: Walkie-Talkies (user presses "Push-To-Talk" and speaks "Over").
Bidirectional Simultaneous
Both stations can transmit and receive data simultaneously. The link capacity is divided between the two directions.
Examples: Mobile telephone conversations, modern Ethernet switches.
Geographical Classification of Networks
| Parameter | PAN (Personal) | LAN (Local) | MAN (Metropolitan) | WAN (Wide Area) |
|---|---|---|---|---|
| Coverage Range | Up to 10 meters | Up to 1 km (room/campus) | Up to 50 km (citywide) | Country / Global |
| Data Transfer Rate | Moderate (Bluetooth 24 Mbps) | Highest (100 Mbps - 10 Gbps) | High (44 - 155 Mbps) | Variable / Lower per node |
| Transmission Media | Bluetooth, Zigbee, USB | Twisted pair, Wi-Fi, Fiber | Coaxial, Optical fiber | Satellite, Undersea Fiber |
| Ownership | Single Individual | Single Enterprise/School | Public / Consortium | Distributed / ISP Consortium |
| Classic Example | Smartphone connected to smartwatch | School Computer Laboratory | City Cable TV Network | The Global Internet |