ethernet wiring

[alacant]

Apologies in advance for the noise. I tried an electronics forum but received indecipherable replies.
I wonder if there is anyone here who can give me a simple answer to this question...

I have this re-usable rj45 plug with 4 attachment points above labelled A and 4 below, B.
Question: which wire from a category 5e cable do I put where? Alongside is the wiring of a conventional plug which I'm trying to imitate.

TIA and clear skies.
   

Edited August 24, 2023 by alacant

[symmetal]

There are two wiring conventions for RJ-45 ethernet connectors called T-568A and T-568B. The difference is that the orange and green pairs are swapped over between the two standards.

Ethernet cables are wired straight through so if the same is used for both end then either method works. If you want an ethernet crossover cable to connect two PCs together without going via a router or switch inbetween then you wire one end as T-568B and the other as T-568A.

https://incentre.net/ethernet-cable-color-coding-diagram/

Standard ethernet cables you buy are wired to T-568B at both ends. The colour coding in your picture is T-568A so is that what you actually need.

Here;s your connector wired to the common T-568B which is probably what you want.

The top two colour rows labelled B are the ones used here. If you wanted to wire it as T-568A you would use the bottom two colour rows labelled A. Note it's just the orange and green pairs that are swapped over which is the difference between A and B. These are the ethernet transmit and receive pairs. The blue and brown pairs aren't used for standard ethernet cables but can be used for supplying power to devices like IP cameras when it's called a POE connection. (Power over ethernet).

Nowadays, crossover cables generally aren't needed as modern PCs can usually detect what signal is on the wires and if necessary make the changeover internally automatically so a standard ethernet patch cable can be used between two PCs. 

Alan

 

Edited August 24, 2023 by symmetal

[symmetal]

I've just noticed the colour coding on the connector you posted is different from the one I posted so you'll need to change your wire colours to match. For T-568B as looking at your photo

Top row left to right     Orange/White,   Orange,   Green/White,   Green

Bottom row left to right  Blue,   Blue/White,   Brown,   Brown/White

Confusing isn't it 🙂

Alan