Network Topologies & Hardware
Understand the physical and logical layout of computer networks, and the core hardware components that make them run.
Network Topologies
A topology describes the arrangement and connections of a network's nodes (devices) and links.
1. Star Topology
All nodes connect to a single central hub or switch. If one cable breaks, only that node goes offline. Highly scalable and easy to manage.
Most modern office and home LANs use a star topology with a switch or wireless router at the center.
2. Mesh Topology
Every node is connected to multiple other nodes. A full mesh connects every single node directly. Highly redundant and fault-tolerant, but extremely expensive and complex to wire.
3. Bus Topology
Devices connect to a single backbone cable (bus). Terminators are required at both ends. If the main cable breaks, the entire network fails. Older technology, rarely used today.
4. Ring Topology
Nodes are connected in a closed loop. Data travels in one direction (or both in dual rings). If a node fails, the loop breaks. Token Ring is a classic example.
Essential Networking Hardware
Networks depend on physical devices to move data packets from one point to another:
Network Interface Card (NIC)
The hardware component (circuit board or chip) built into a device that allows it to connect to a network. Each NIC has a unique, hardcoded MAC (Media Access Control) address.
Hubs vs. Switches
- Hub — A simple Layer 1 (Physical) device. It broadcasts incoming data to all connected ports, causing network congestion and security concerns. Legacy hardware.
- Switch — A Layer 2 (Data Link) device. It learns MAC addresses and forwards data packets only to the specific port of the destination device. Highly efficient.
Router
A Layer 3 (Network) device that connects different networks (e.g., your local home network to the internet WAN). Routers look at IP addresses to determine the best path for data packets.
Modem (Modulator-Demodulator)
Converts signals between your ISP's analog infrastructure (cable, fiber, DSL) and your digital home router.
Access Point (AP)
Extends a wired network by broadcasting a wireless (Wi-Fi) signal, allowing devices to connect without physical cables.
Cabling Types
- Twisted Pair (Copper) — Uses Ethernet cables (Cat5e, Cat6, Cat6a). Maximum run of 100 meters.
- Fiber Optic — Uses light pulses through glass fibers. Insensitive to electrical interference. Can travel miles at extremely high speeds.
- Coaxial — Used for cable television and broadband internet connections.
What's Next?
Learn how routers and switches work together to forward packets in Routing & Switching, or read about TCP/IP to see how protocols organize data for these devices.