The cable next to the mains
A new cable run goes along the ceiling, tied right beside a thick power cable. The computers work, but the connection slows down in the afternoon when the machines nearby switch on.
The signal is being disturbed. Cabling risk is about the cable, its path and its setting.
By the end of this lesson
Note
I can name the risks to a cabling system and assess one cabled LAN.
Key words
| Word | What it means | Example |
|---|---|---|
| Interference | an unwanted signal that disturbs the wanted one | Noise from a mains cable |
| Signal | the electrical, light or radio wave that carries data | |
| Cable run | the path one cable takes from one end to the other | |
| Patch panel | a board in a cabinet where cables from the walls end | |
| Network | computers and devices linked so they can share data | |
| LAN | local area network: a network inside one building | |
| Firewall | a filter that allows or blocks traffic between computers | |
| Component | one part of a system |
The cells students fill in are left blank in this preview.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Risks that matter to a cabling job
Cabling has risks of its own.
A rodent that chews cables. Wi-Fi dropouts. Systems that cannot be reached. A firewall setting that blocks the wrong traffic. Interference of the signal.
Cabling risks and how to lower them
| Risk | What happens | How to make it smaller |
|---|---|---|
| Rodent chewing cables | Cut or damaged cable, lost link | Seal gaps, use trunking and check regularly |
| Interference | Slow link or lost data | Keep data cables away from mains cables |
| Wi-Fi dropouts | Calls and pages cut off | Check access point positions and signal strength |
| Inaccessible system | Users cannot reach a service | Check the link, the port and the device |
| Firewall setting wrong | Good traffic blocked | Review rules and test every change |
| Damp or heat in a cabinet | Corroded or failing connections | Keep cabinets dry and cool |
The cells students fill in are left blank in this preview.
Assess a cabled LAN
The spec asks you to assess a local area network cabling system. List its components: outlets, cable runs, patch panel, patch leads, switch ports and the cabinet.
Then find a risk for each part, rate probability and impact, and put them in order.
Worked example: cabling in a classroom block
| Risk | Probability | Impact | Score | Order |
|---|---|---|---|---|
| Patch lead across a walkway, a trip hazard | 3 | 4 | 12 | 1 |
| Contractor cuts a cable run | 3 | 3 | 9 | 2 |
| Data cable tied beside mains cable | 3 | 3 | 9 | 3 |
| Cables with no labels slow every repair | 4 | 2 | 8 | 4 |
| Rodent damage in the roof space | 2 | 3 | 6 | 5 |
The cells students fill in are left blank in this preview.