Guides/Introduction
Introduction to
Ethernet cables.
What an Ethernet cable is made of, what the categories mean, and which differences actually change what you get.
Eight conductors, four pairs, and the twist that makes it work.
Two wires carrying the same signal in opposite polarity cancel out most of the interference they pick up. The tighter the twist, the better that cancellation holds at high frequencies. Everything else in the cable exists to protect that geometry.
Jacket
The outer sheath. PVC indoors; polyethylene outdoors, for UV and moisture.
Pairs
Four, each with its own twist rate so that adjacent pairs do not couple into one another.
Separator
A spine or film between the pairs on some constructions, to hold them apart and reduce crosstalk.
Shielding
Foil, braid or both. Present on some constructions and absent on others.
Conductor
The metal itself and its gauge. Both are stated on every Mr. Tronic listing — see below.
A category is a construction specification,
not a promise about your connection.
It sets the bandwidth the cabling has to support and, with it, the data rate the standard allows. It cannot make a connection faster than the line into the building or the ports at each end.
| Category | Bandwidth | Data rate allowed by the standard |
|---|---|---|
| Cat 5e | 100 MHz | 1 Gbps up to 100 m |
| Cat 6 | 250 MHz | 1 Gbps up to 100 m · 10 Gbps up to 37–55 m* |
| Cat 7 | 600 MHz | 10 Gbps up to 100 m |
* Over Cat 6 the standard allows 10 Gbps to 37 m in any installation, and to 55 m where interference from neighbouring cables is low.
A category sets a ceiling. What a particular cable delivers depends on how it is built, so the rating of each Mr. Tronic range is stated on its listing — not inferred from the ceiling of its category. The distances are compared side by side in Speed and Performance.
The difference two prices
usually come down to.
Two metals are used in network cable. It is the specification most often left out of a product listing, and the one that explains why two apparently identical cables cost differently.
Solid copper
The lowest resistance of the two, and what the cabling standards specify.
It is also what any application that carries power over the cable, such as Power over Ethernet, calls for: current through a conductor becomes heat, and copper wastes the least of it.
Copper-clad aluminium
An aluminium core with a copper skin. Lighter, more flexible and considerably more economical, with roughly 55 % more resistance than copper.
Carries data at gigabit rates over the distances found in a home or a small office, which is what the great majority of network cable is asked to do.
Our Cat 5e and Cat 6 ranges use copper-clad aluminium in AWG24. Our Cat 7 range uses solid copper in AWG28. Every listing states which.
Neither metal is a defect and neither is a substitute for the other: they are different products at different prices. What is not acceptable is not telling you which one is in the box, and a great many listings do not.
Four ways to find out,
from easiest to most certain.
Conductor material is not always declared, and when it is missing that is itself information. These checks work on any cable, ours included.
Read the listing
Look for the conductor and the gauge, in the form “CCA, AWG24” or “solid copper, AWG23”. If a listing gives you the category, the length and the colour but not the metal, it is reasonable to assume the more economical one.
Weigh it
Aluminium is far lighter than copper, so a reel of the same length and gauge weighs noticeably less in CCA. Useful when you have both to compare, less so on its own.
Look at a cut end
Solid copper is the same colour all the way through. On copper-clad aluminium, scraping or filing the tip of a conductor exposes the silver-coloured aluminium under the copper skin. This is the check that settles it.
Consider the price
Copper is a traded commodity with a floor. A cable priced far below everything comparable is telling you something about its construction, and usually it is this.
We sell both kinds, and we say which is which on every listing. A buyer who knows what to look for is a buyer who is not disappointed later — and the alternative, a market where nobody declares the conductor, is worse for everyone selling an honest product.
Two more decisions.
The first changes what is wrapped around the pairs. The second changes the shape of the cable and how it arrives.
Unshielded · U/UTP
Nothing between the pairs and the jacket. The twist does the work on its own.
Shielded · F/UTP
A foil wrap closes around the four pairs, inside the jacket.
Bulk arrives on a reel with no connectors, so each lead is cut to the length the route needs and terminated by whoever fits it.
Terminated arrives with an RJ45 moulded at each end, ready to plug in.
T568A and T568B.
Both work. Mixing them does not.
Two pin assignments are in use. Either one, used consistently, gives you a straight-through cable. Using one at one end and the other at the other end produces a crossover instead — which is the single most common self-inflicted fault when terminating by hand.
T568A
Green pair on pins 1 and 2.
T568B
Orange pair on pins 1 and 2.
Only the four outlined positions change between the two — the orange and green pairs trade places. Blue on pins 4 and 5 and brown on pins 7 and 8 sit in the same place either way. Pin 1 is on the left with the clip facing away from you. How far the pairs may be untwisted at the connector is in the Installation Guide.
Every listing states the conductor.
Category, length, colour, gauge and the metal itself — on every reference we sell, not only on the ones where it flatters us.
This page is general guidance about the technology. The instructions for a specific Mr. Tronic product are at Instructions for Use, searchable by the EAN printed on the box.