How to extend an ethernet cable with a cheap coupler?

I have a long ethernet LAN cable buried in the wall and replacing the the whole thing is not an option.

I simply want to extend the cable a bit without bringing a network guy home. I have lots of ethernet cables.

I think the LAN is Gigabit Ethernet (I'm not sure, but I can check if it's needed).

My question is - what I need to do is buy a RJ45 and simply connect another ethernet cable at the other end, and connect it to the computer? Or something else?

traveh

Posted 2015-08-05T11:44:53.143

Reputation: 554

Google 'ethernet extender cable' – Tetsujin – 2015-08-05T11:47:14.433

I did, that's how I came up with the RJ45, but I want to make sure it does what I think and that it will work with Gigabit ethernet. – traveh – 2015-08-05T11:48:53.727

I also checked on Wikipedia but it wasn't completely clear to me. – traveh – 2015-08-05T11:49:40.723

you just need a female to male instead of the usual male to male. Anything cat 5e or up ought to do it, unless you're really going a long way, in which case cat 6 – Tetsujin – 2015-08-05T11:50:44.303

Hmm I googled female to male and it I think what I need is female to female little box thingy, if I already have the extra male-to-male cables, no? – traveh – 2015-08-05T11:54:08.780

Will the total extended length of the cable be less than 100M, and is are its tips wired in "Straight-through" (standard) layout? you can tell, by holding up both ends of the cable so the tips are side by side, with teh clip down. the White-Orange cable should be the left most on both tips, and the other wires should all match from left to right. – Frank Thomas – 2015-08-05T11:56:32.727

@FrankThomas yes, the total length should be only about 10M. Both cables are standard ethernet LAN cables (no crossover cables). I'm not sure about the colors - I'll check when I'm back home... – traveh – 2015-08-05T12:00:22.263

http://www.aliexpress.com/store/product/RJ45-extender-coupler-Connector-for-RJ45-Ethernet-LAN-Cable/200516_311373045.html – qasdfdsaq – 2015-08-05T12:48:11.063

Answers

Presuming that you won't be breaking the 100-Meter maximum lenght specification, a simple gender-swapping coupler should allow you to connect the two cables as you describe. There are a couple potential gotcha's however.

First, both cables would should use a compatible wiring scheme. Standard ethernet cable uses a Straight-Through layout, but there are also several other layouts, such as Cross-patch/Cross-over. If the cable in the wall is cross-over, be sure to use a straight-through cable to extend. Most combinations will work, but there are a few to be careful of, especially if the nics in one of the connecting devices don't support auto-pin mapping (MDI-X)

Second, you may notice that after installing the coupler, that power/signal drops, and you are resending more signals than is optimal. in that case, some kind of active repeater/bridge/switch will be required. if you have seen powered devices online, these are essentially single port repeaters, which boost signal as it passes through. Note however that a repeater is an analog technology, and will amplify noise as well as it amplifies desirable signal. if there is too much noise on the line, only a fully fledged digital device like a switch or bridge will fix that.

Frank Thomas

Posted 2015-08-05T11:44:53.143

Reputation: 29 039

The simplest method is to use a coupler known as a RJ45 Coupler. It is simply two RJ45 sockets connected straight through and allows you to plug in the ends of two Ethernet cables to effectively extend the length. They can be found for pennies on popular on-line auction and electronic/computer retail sites.

albal

Posted 2015-08-05T11:44:53.143

Reputation: 1 155

6nice use of mirror. – Frank Thomas – 2015-08-06T11:43:49.293