Overview of computer networking concepts, including the importance of networking, key terminologies, and basic network components.
Introduction to Computer Networking
Key concepts, terminology, and foundational models
| Aspect | Description |
|---|---|
| Definition | A collection of interconnected devices (computers, phones, sensors, etc.) that can exchange data and share resources. |
| Purpose | Communication, resource sharing (files, printers, internet), distributed computing, and data collection. |
| Scale | Ranges from a few devices in a home (LAN) to millions of devices worldwide (Internet). |
| Term | Meaning |
|---|---|
| Node | Any device that can send, receive, or forward data (e.g., PC, router, switch, IoT sensor). |
| Link | Physical or logical connection between two nodes (copper cable, fiber, wireless link). |
| Protocol | A set of rules governing how data is formatted, transmitted, and received (e.g., TCP, HTTP). |
| Topology | Physical or logical arrangement of nodes and links (star, mesh, bus, ring). |
| Bandwidth | Maximum data rate a link can carry, usually expressed in bits per second (bps). |
| Latency | Time taken for a packet to travel from source to destination (measured in milliseconds). |
| Throughput | Actual data rate achieved, often lower than bandwidth due to overhead and congestion. |
| IP Address | Unique numeric identifier for a host on an IP network (IPv4: 32‑bit, IPv6: 128‑bit). |
| MAC Address | Hardware address of a network interface card (48‑bit, used in the data‑link layer). |
| Scope | Typical Size | Example Technologies |
|---|---|---|
| PAN (Personal Area Network) | < 10 m | Bluetooth, ZigBee |
| LAN (Local Area Network) | Building or campus | Ethernet, Wi‑Fi (802.11) |
| MAN (Metropolitan Area Network) | City‑wide | Fiber‑to‑the‑node, Metro Ethernet |
| WAN (Wide Area Network) | Country/continent | MPLS, leased lines, satellite |
| CAN (Campus Area Network) | University or corporate campus | High‑speed Ethernet, fiber |
| Internet | Global | TCP/IP, DNS, HTTP/HTTPS |
| Layer | Name | Primary Function | Typical Protocols / Devices |
|---|---|---|---|
| 7 | Application | End‑user services (email, web, file transfer) | HTTP, FTP, SMTP, DNS |
| 6 | Presentation | Data translation, encryption, compression | TLS/SSL, JPEG, ASCII |
| 5 | Session | Establishes, manages, terminates connections | NetBIOS, RPC |
| 4 | Transport | End‑to‑end reliability, flow control | TCP (reliable), UDP (unreliable) |
| 3 | Network | Routing, logical addressing | IP, ICMP, routers |
| 2 | Data Link | Frame formatting, MAC addressing, error detection | Ethernet, PPP, switches |
| 1 | Physical | Transmission of raw bits over a medium | Copper, fiber, radio, hubs |
Why it matters: The model isolates functions, making design, troubleshooting, and protocol development systematic.
| Layer | OSI Equivalent(s) | Core Protocols