Network cabling - Straight through or crossover...

Diggsy · 12 Sep 2020 at 23:37

...does it really matter? I’ve genuinely no idea if I have used the correct setup. What I do know is that I wired all of the CAT 6 connectors as 568B (I think that makes all my wiring straight through?).

I have solid CAT 6 cabling throughout my house, including 3 different switches (all unmanaged Netgear), 2x 5 ports and 1x 8 ports.

My setup is as follows...

Sky router, which leads to;
Netgear 5 port, which feeds;
Hue, Blu-ray, Apple TV, and on to;
Netgear 8 port, which feeds;
Apple TV, 2x Sky boxes, Smart TV etc, then onto;
Netgear 5 port, which feeds a PC, PS4, Netgear wireless access point and Apple TV.

Everything works as expected (as far as I can tell), however I am wondering if I should have used a particular cable in each case - straight through or crossover, and what difference it makes, or if it simply doesn’t matter with modern equipment.

Hopefully someone can clear this up for me. Thanks

Zefan · 12 Sep 2020 at 23:40

Everything recent should be using a technology called auto mdix, which automatically works out what it's talking to on the other side and changes the tx/rx pins accordingly.

:edit: recent in this case means anything released in the last 10 years at least! There are bound to be some fringe devices that don't do it, but all standard consumer devices will.

Diggsy · 12 Sep 2020 at 23:47

Zefan said:
Everything recent should be using a technology called auto mdix, which automatically works out what it's talking to on the other side and changes the tx/rx pins accordingly.

Perfect...Seems it shouldn’t matter what way my connectors are wired then.

Thank you for clearing that up for me!

bremen1874 · 13 Sep 2020 at 00:01

You'd only use crossover cables for direct connecting devices (i.e. no hub or switch) in the days before Auto MDI-X. As above, you'd be hard-pressed to find anything that isn't nowadays.

When you're installing cabling you use the same standard at both ends (568A or 568B). 568B is more common, but you can use either one.

Diggsy · 13 Sep 2020 at 07:42

bremen1874 said:
You'd only use crossover cables for direct connecting devices (i.e. no hub or switch) in the days before Auto MDI-X. As above, you'd be hard-pressed to find anything that isn't nowadays.

When you're installing cabling you use the same standard at both ends (568A or 568B). 568B is more common, but you can use either one.

Thank you. All of mine are terminated in 568B, so seems I’ve luckily finished them off properly. Completely by chance mind you, as I was blissfully unaware at the time