Crimping network cables

By Atomstar on Sunday 31 March 2019 20:35 - Comments (13)
Category: Smarthome, Views: 4.021

Although most of us (including me) are familiar with making our own network cables/jacks, I recently wired network cable in my house learned some new things/abbreviations on cable thickness, cable material, pin termination, cross-over vs straight cables. I document my findings here for reference and case I forget in the future

Glossary

UTP ('Unshielded Twisted Pair') - A type of cable where the pairs of wires are twisted to improve signal quality, there are different shielding flavours available: U/UTP F/UTP U/FTP F/FTP
CAT (‘Category') a type of twisted pair cable specifically for Ethernet
AWG ('American wire gauge') - a certification for cable thickness, lower is thicker.
RJ ('Registered jack') - a type of jack/connector, RJ45 is commonly used for for ethernet as it has 8 pins
Punch down tool (also known as LSA punch down) - a tool to punch wires in to IDC.
T568A/B - a type of wiring/termination schema for telecommunication
IDC ('Insulation-displacement connector') - a connector where the insulation of the wire is removed upon installation

Hardware

Cable

Get a UTP cable cable. Things to watch out for:

CATx: CAT6 for Gigabit, or more if you're ambitious
AWG: Ideally around AWG 23
Solid copper wires or stranded in case of need for flexibility (thanks sebastius)
Shielding is nice but only needed in high noise environments (maybe next to electricity wires).
Material: watch out for cheap cables which have copper-clad aluminium. To test, put the wire in a flame, aluminium will melt/burn, copper will stay intact (although this test methods means you need to have the cable )

Connectors

Get RJ45 jacks

ensure they match your cable thickness.
ensure they're matched to solid/stranded cables (thanks GoT!)

Installation

Pull the cable where you need it, when pulling them through tubes, lubricate with Vaseline or similar if you have difficulty. However note that vaseline might dry out and make the next pull more difficult (thanks RobIII).

Terminate the cables, either in a wall socket, or with a RJ45 plug. When terminating, be sure to:

ensure you terminate each cable to the same pin on both ends (’straight’), cross-over cables are not necessary since 1998 when Auto MDI-X was introduced.
When connecting the cable to the wall socket, a punch down tool might help in case of IDCs.
When connecting the cable to a plug, ensure you have a crimping tool.
It matters how your terminate the wires on each end (thanks vanaalten), T568B (thanks Wildfire) is used by default so stick to this.

04-'19 VLAN tagging on OpenWRT/managed switches
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Comments

By Wildfire, Sunday 31 March 2019 21:52

Correction, T568B is used by default. At least every cable I've seen over the past few years has been T568B.

By Atomstar, Sunday 31 March 2019 21:56

Wildfire wrote on Sunday 31 March 2019 @ 21:52:
Correction, T568B is used by default. At least every cable I've seen over the past few years has been T568B.

Thanks! Fixed!

By GoT, Sunday 31 March 2019 23:07

Always use RJ45 jacks that are for solid cables.
http://www.l-com.com/cont...icle.aspx?Type=N&ID=10592

If it's not clearly specified, it usually is for stranded cable.
The better PC/network shop will have it specified, whether it be for stranded or solid,
If you use the wrong jack: stranded jack on solid cable it will damage the copper core.
Reverse: if you use "solid" jack on stranded cable, it will still work and make good contact.
So there is no point in buying "stranded" RJ45 jacks, always go for RJ45 jacks for solid cables.
There is usually no price difference between the two jacks, just people who don't know the difference.

By sebastius, Monday 1 April 2019 09:49

GoT wrote on Sunday 31 March 2019 @ 23:07:
Always use RJ45 jacks that are for solid cables.
http://www.l-com.com/cont...icle.aspx?Type=N&ID=10592

If it's not clearly specified, it usually is for stranded cable.
The better PC/network shop will have it specified, whether it be for stranded or solid,
If you use the wrong jack: stranded jack on solid cable it will damage the copper core.
Reverse: if you use "solid" jack on stranded cable, it will still work and make good contact.
So there is no point in buying "stranded" RJ45 jacks, always go for RJ45 jacks for solid cables.
There is usually no price difference between the two jacks, just people who don't know the difference.

Yeah but please don't use solid cable for connecting to machines (only in permanent infrastructure). Solid copper breaks. Stranded flexes.

By RobIII, Monday 1 April 2019 11:15

lubricate with Vaseline or similar

Only if you ABSOLUTELY have to. Whatever you use; it will dry up and years later you'll have a cable that won't come out or be impossible to pull another one into the same tube because it's too sticky in there. And before you resort to 'vaseline or similar', try wrapping the cable in a wet cloth with a very thin solution of water and soap and pulling the cable trough the cloth as it goes is..

By woxx, Monday 1 April 2019 11:22

Atomstar wrote on Sunday 31 March 2019 @ 21:56:
[...]

Thanks! Fixed!

Memory aid for T568A or T568B is: T568B(enelux)

[Comment edited on Monday 1 April 2019 11:22]

By Pietervs, Tuesday 2 April 2019 08:51

Although it doesn’t matter how you terminate the wires on each end
It doesn't matter as long as you terminale both ends in the same manner...

By Harm_H, Tuesday 2 April 2019 13:22

Ik vind het jammer dat ik geen buisje heb gebruikt, maar de kabel gewoon onder de vloer heb gelegd

By vanaalten, Tuesday 2 April 2019 14:23

Pietervs wrote on Tuesday 2 April 2019 @ 08:51:
Although it doesn’t matter how you terminate the wires on each end
It doesn't matter as long as you terminale both ends in the same manner...

You're both wrong. It does matter how you terminate, since it is essential to keep the pairs correctly together.

For example, pins 1 and 2 are one datapair, 3 & 6 are another, 4 & 5 are a pair and 7 & 8 are a pair. Each pair should be connected to "color, white+color" wires. And both ends should be connected in the same way.

So it is OK to have on both ends pin 1 & 2 terminated with orange & white-orange, or green & white-green, but definitely not orange & white-green.

Better don't mess with this and use T568B.

By Atomstar, Tuesday 2 April 2019 19:04

Thanks all for your suggestions, I've updated the guide accordingly

By redfox314, Tuesday 2 April 2019 23:39

Don't use vasiline to lubricate a wire. It will become sticky very quickly and basically glue your cable in the tube. Just get some cable lubricant like 3M Lub-I.

By Hindelaufen, Wednesday 3 April 2019 13:05

RobIII wrote on Monday 1 April 2019 @ 11:15:
[...]

Only if you ABSOLUTELY have to. Whatever you use; it will dry up and years later you'll have a cable that won't come out or be impossible to pull another one into the same tube because it's too sticky in there. And before you resort to 'vaseline or similar', try wrapping the cable in a wet cloth with a very thin solution of water and soap and pulling the cable trough the cloth as it goes is..

When I pull cable and it gets stuck, I use talcum powder. Just put the entire cable in a plastic bag and put two or three table spoons of talcum powder in it too. Then just shake thoroughly.
The talcum powder will never dry out (it is already bone dry) and leaves a slippery cable surface. You only might to vacuum clean the inlet and outlet of your cable tube.

By PeterVO, Thursday 4 April 2019 08:33

On shielding: The names of wires is a/bTP where: a is the shielding of the cable and b is the shielding of every pair. The shielding can be U for no shielding, S for shielded with a layer of thin wires or F for foiled.

In normal domestic environments shielding is NOT needed. Only when you have heavy electrical machines it might be needed. The noise here is electrical noise, mostly from electrical motors.

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