Lesson 2: Network Topologies and Scope

Physical vs. Logical Topologies

• Physical Topology: How the devices are physically wired and connected (Bus, Ring, Star, Mesh).
• Logical Topology: How the data flows between devices, independent of the physical layout (e.g., how Ethernet data flows).

Today, the Star Topology (where all devices connect to a central device, usually a switch) is the dominant physical standard.

Network Scope Classifications

Networks are classified by their geographic reach:

1. LAN (Local Area Network): A network in a small, localized area, like a single office building or campus. Characterized by high bandwidth and low latency.
2. WAN (Wide Area Network): Connects LANs across large geographical distances (e.g., across cities, states, or countries). Uses services from service providers (ISPs).
3. MAN (Metropolitan Area Network): Covers a city or large campus.
4. SOHO (Small Office/Home Office): A simplified network setup, often using a single multi-function device (router, switch, AP, firewall combined).

Introduction to Network Media

Data is transmitted via media:

• Copper Cables: Transmits electrical pulses (e.g., Ethernet UTP/STP).
• Fiber Optic Cables: Transmits pulses of light (used for high speeds and long distances).
• Wireless: Transmits electromagnetic waves (Wi-Fi, Cellular).