Computer Networking Concepts

Computer Networking Concepts

• Computer networking connects computers for shared resources via the internet.
• Sharing resources includes browsing the web, sending/receiving email, sharing files, and downloading media.
• Organizations (companies, schools, government) often use networks for tasks like word processing, science computing, and control systems.

Network Categories by Geography

• Personal Area Network (PAN): Smallest network, connecting compatible personal devices (e.g., headphones to phone, computer to printer).

• Local Area Network (LAN): Connects computers in a limited area (a building, house, or group of buildings).

• Campus Area Network (CAN): Connects buildings in a campus environment (universities, large organizations).

• Metropolitan Area Network (MAN): Connects buildings across a city (e.g., traffic lights, parking meters).

• Wide Area Network (WAN): Largest network, covering vast areas (cities, provinces, countries), often combining LANs and MANs.

Network Architecture

• Network architecture is a diagram showing network structure and services to meet client needs.
• Common network architectures focus on client needs.
• Access Networks: Connect users and devices together.
• Data Center Networks: Connect servers for data access.
• Wide-Area Networks (WANs): Connect users to programs and services.

The OSI Model

• The Open Systems Interconnection (OSI) model is a layered networking standard for communication.
• Physical Layer: Provides the electrical and mechanical interface to the network.
• Data Link Layer: Manages error recovery, flow control
• Network Layer: Acts as the network controller (routing)
• Transport Layer: Handles end-to-end message delivery.
• Session Layer: Manages connection setup and teardown.
• Presentation Layer: Formats and codes data.
• Application Layer: Handles user application requests like browsing, sending email.

Wired Network Devices & Wireless Devices

• LAN Ethernet Cable: Connects devices within a local area, limited by length and cable quality.
• Hub: Connects multiple devices, but broadcasts traffic to all connected devices.
• Switch: Connects devices directly, improving privacy.
• Cable Modem: Connects home network to internet service provider (ISP).
• Servers: Provide resources, data, and services to other computers.
• Firewalls: Security devices monitoring network traffic.
• Wireless Access Point: Connects wireless devices to a wired network.
• Wireless Routers: Combines router/switch/access point functionality (common in home networking).

Network Topologies

• Point-to-Point: Two devices directly connected.
• Token Ring: Access to transmissions is regulated.
• Bus Topology: Computers share the same transmission media (coaxial cable).
• Star Topology: All devices connect to a central switch or hub; commonly seen in LANs today.
• Mesh Topology: Devices are directly interconnected; can be fully meshed or partially meshed.