Lesson 8: Cables and Connectors
Twisted-Pair Copper Cabling (UTP/STP)
Unshielded Twisted Pair (UTP) is the most common cable type in modern LANs. The twisting of the wires reduces electromagnetic interference (EMI).
Ethernet Standards
| Standard | Speed | Max Distance |
|---|---|---|
| 10BASE-T | 10 Mbps | 100 meters |
| 100BASE-TX | 100 Mbps | 100 meters |
| 1000BASE-T | 1 Gbps | 100 meters |
| 10GBASE-T | 10 Gbps | 100 meters |
Cable Types
- Straight-Through: Used to connect dissimilar devices (Host to Switch, Router to Switch). Wires are identically pinned on both ends (T568B is the dominant standard).
- Crossover: Used to connect similar devices (Host to Host, Switch to Switch, Router to Router). Transmit pairs on one end are wired to Receive pairs on the other. (Note: Modern devices often use Auto MDI/MDIX, making crossover cables obsolete for most connections).
- Rollover/Console: Used for connecting a PC to the console port of a Cisco device for management.
Fiber Optic Cabling
Uses light pulses instead of electrical signals. Immune to EMI and supports extremely long distances and high bandwidth.
- Single-Mode Fiber (SMF): Used for very long distances (kilometers). Requires laser optics.
- Multi-Mode Fiber (MMF): Used for shorter distances (up to 400m). Uses cheaper LED optics.