Networking · Topic 10 of 10
Networking Tools and Their Purposes
Learn what crimpers, cable strippers, punchdown tools, tone generators, cable testers, loopback plugs, taps and Wi-Fi analyzers do and when to use each.
- 4 min
- A cable stripper removes the jacket; a crimper attaches a connector; a punchdown tool seats wires in a jack or panel.
- A cable tester finds opens, shorts and miswires.
- A toner and probe trace a cable through walls or bundles.
What it is
Network technicians use a small set of hand tools and testers to build cables, wire jacks and find faults. Each tool has one clear job, and the exam asks you to match the tool to the task.
How it works
Tools for making cables
| Tool | Purpose |
|---|---|
| Cable stripper | Removes the outer jacket from a cable without cutting the wires inside |
| Wire cutter (snips) | Cuts cable and trims wire ends |
| Crimper | Fixes a modular plug such as RJ45 onto the end of a twisted pair cable |
| Punchdown tool | Pushes each wire into a slot in a patch panel or wall jack, trimming the extra |
A crimper attaches a Registered Jack 45 (RJ45) plug, the connector used on Ethernet cables. A punchdown tool seats wires in a 110 block or keystone jack. The punchdown tool is used for the fixed cable in walls, not for patch cables.
Wiring standards
Ethernet cables use eight wires in four pairs, and there are two standards for the order. Both ends of a normal cable use the same one.
| Pin | T568A | T568B |
|---|---|---|
| 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 |
A straight through cable has the same standard on both ends and joins unlike devices, such as a computer and a switch. A crossover cable has T568A on one end and T568B on the other, and used to link like devices directly. Modern devices usually sense this by themselves.
Tools for testing and tracing
| Tool | Purpose |
|---|---|
| Cable tester | Checks that each wire is connected to the right pin; shows opens, shorts and swapped wires |
| Toner (tone generator) and probe | A tone is placed on one end of a cable, and the probe finds the matching cable among many |
| Loopback plug | Plugs into a port to send a signal back to itself, so you can test the port or network card |
| Network tap | Copies traffic passing along a link to a monitoring device without disturbing it |
| Wi-Fi analyzer | Shows nearby wireless networks, their channels and signal strength |
An open is a broken wire, a short is two wires touching and a miswire (or split pair) is wires in the wrong places. A basic cable tester shows continuity and pin order, but it does not measure speed.
How the tools fit together
To run a new cable to a wall jack: strip the jacket, punch each wire into the jack, then do the same at the patch panel. Make a patch cable with a crimper at each end.
Test every cable with a tester. If a cable is unlabeled in a bundle, use the tone generator and probe to find it.
To check a Wi-Fi problem, use the analyzer to see crowded channels and weak signal areas, then move the channel or the access point. To watch what crosses a link, use a tap with a capture device.
A tone generator and probe finds where a cable goes; a cable tester checks that the cable is wired correctly. Questions often swap these two roles.
Safety and care
Cut and strip carefully and keep cables away from power wiring. Use a tester before any cable goes into service, since bad terminations cause hard to find faults later.
What to remember for the exam
- A cable stripper removes the jacket; a crimper attaches a connector; a punchdown tool seats wires in a jack or panel.
- A cable tester finds opens, shorts and miswires.
- A toner and probe trace a cable through walls or bundles.
- A loopback plug tests a port or network card.
- A network tap copies traffic for monitoring.
- A Wi-Fi analyzer shows channels and signal strength.
- Straight through cables use the same standard at both ends; crossover cables use T568A on one end and T568B on the other.
- Wire order matters: a wrong pair order, even with the right plugs, causes faults such as crosstalk.
Common mistakes
Using a crimper where a punchdown is needed. Wall jacks and patch panels use a punchdown tool.
Mixing wiring standards on one cable by accident. One end A and one end B makes a crossover cable.
Untwisting too much wire. Pulling pairs apart too far before the plug raises interference.
Assuming a tester measures speed. It checks wiring, not the performance of the link.
Mistaking a tone generator for a tester. It locates a cable but does not prove the wiring is right.
Check yourself
Which tool attaches an RJ45 plug to a cable?
A crimper.
Which tools together help find an unlabeled cable?
A tone generator and a probe.
What does a loopback plug test?
A port or network card, by sending its signal back to itself.
Topic 10 of 10 in Networking
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