Cabling Standards - buaamer81/IT130-Networking-Wiki GitHub Wiki
๐ Cabling Standards
๐ Overview
Cabling standards ensure consistent and reliable connections in network installations. These standards define the wiring order, cable types, fire safety, and labeling practices used across the industry.
Two of the most important standards are:
๐งต TIA/EIA Standards
The TIA/EIA-568 family of standards defines how to properly wire and terminate twisted-pair cabling for Ethernet networks.
โ TIA/EIA-568A vs TIA/EIA-568B
- Both define the color coding of the 8 wires inside an Ethernet cable.
- The only difference is the order of green and orange pairs.
๐ Pinout Chart
| Pin | T568A Color | T568B Color |
|---|---|---|
| 1 | White/Green | White/Orange |
| 2 | Green | Orange |
| 3 | White/Orange | White/Green |
| 4 | Blue | Blue |
| 5 | White/Blue | White/Blue |
| 6 | Orange | Green |
| 7 | White/Brown | White/Brown |
| 8 | Brown | Brown |
๐ง Tip: Use the mnemonic โGOโ โ Green/Orange โ to remember the swap between A and Bโ:contentReference[oaicite:0]{index=0}.
๐ Cable Types
๐น Straight-through Cable
- Same standard on both ends (e.g., 568B to 568B).
- Used to connect unlike devices (PC to switch, switch to router).
๐น Crossover Cable
- One end 568A, the other 568B.
- Used to connect like devices (PC to PC, switch to switch).
- Reverses send/receive wiresโ:contentReference[oaicite:1]{index=1}.
๐น Rollover Cable
- Pins are reversed 1-to-8, 2-to-7, etc.
- Used to connect a PCโs serial port to a router or switchโs console port.
- Not for data traffic โ only for management accessโ:contentReference[oaicite:2]{index=2}.
๐ฅ Fire Ratings
Fire ratings determine where cables can be installed safely.
| Rating | Use Case | Notes |
|---|---|---|
| PVC | Standard cable jacket | Cheap but toxic smoke when burned. |
| Plenum | Ceiling spaces (air ducts) | Low smoke, required by code. |
| Riser | Between floors (vertical) | Limited protection vs plenum. |
๐ง Tip: Plenum = Best. Required for commercial buildingsโ:contentReference[oaicite:3]{index=3}.
๐ท๏ธ Labeling Standard (TIA/EIA-606-B)
This standard defines how to:
- Label cables, patch panels, and wall outlets
- Document network infrastructure
- Keep things neat and troubleshootableโ:contentReference[oaicite:4]{index=4}
๐ง Exam Tip
Learn to identify 568A and 568B wiring diagrams.
Know which cables are used in which scenarios: straight-through, crossover, rollover.
๐ Related Terms
Return to: Chapter 3