Can two computers share one Ethernet cable?

[chasrome]

I have one long run of Cat 5e to the far side of my home that needs to be connected to two computers at the end. I understand there are devices that will merge two ports at the switch end and then split two connections at the far end of the cable that can be connected to each computer. I'm told that this set up acts as if there were two cables run (no crosstalk or other interference etc).

How do I set this up? What kind of adapters / splitters do I need to shop for?

[ruirib]

You need a network switch, such as this one: http://www.amazon.com/D-Link-DGS-100...&s=electronics

[dg1261]

I understand there are devices that will merge two ports at the switch end and then split two connections at the far end of the cable that can be connected to each computer.

I think ruirib must have overlooked the part of your post I underlined above. It sounds to me like you already have a network switch.

Does this picture help?

Ethernet splitters are easy to find. Just do a google search.

[BATcher]

You want a switch at the far end, into which you connect the long ethernet cable and the two ethernet patch cables from your two PCs. Here's a cheap but good 10/100 Mbps one. Of course all the data goes up and down the single ethernet wire, but unless you are streaming data on both PCs you probably won't notice this. (I must say that I've never come across an "ethernet splitter"!)

Although this doesn't directly answer your question you could think about binning the long ethernet cable and using Homeplug devices instead, which use your mains wiring instead of the ethernet cable to transfer the data. You need one at the router end, and one per PC at the far end (so a total of three in your case). These ones don't need any additional power sockets, since they plug into the wall socket, and (one of) the PC's mains cables can plug into them.

[ruirib]

I have never used splitters, I would simply use a switch, as I recommended above.

[dg1261]

I don't disagree with the suggestions to add a second network switch, and in fact that's what I do in my own home office. (OTOH, I need more than just two connections so a splitter wouldn't be a solution.)

The OP specifically asked about ethernet splitters, so the other replies didn't answer his question. They do work. The caveat is that if the OP eventually wants a third connection in that far location, he would have been better off getting a second switch anyway.

[Paul T]

A cheap switch is cheaper then splitters and easier.

cheers, Paul

[kenredman]

It is (technically) possible to use just two of the four pairs in a Cat-5 cable to transmit 100Mbps Ethernet - hence you can get two independent Ethernet signals down a single cable. You have two RJ45 sockets connected to one end and two RJ45 plugs at the other.

Normally, 10/100 Mbps Ethernet uses only the Orange and Green pairs.

RJ45-pinout.gif
















The above image shows a 'normal' Ethernet connection

2 ethernet in single cable.gif

The above shows splitting the cable pairs between two separate RJ45 sockets. The wiring of the plug ends must match.

However, it's messy and unreliable. Buy yourself a cheap Ethernet switch/hub.

[scaisson]

kenredman is correct re using a single Cat wire for two separate networkings.
There does exist 'Y splitter" for Cat5 cable. It looks a lot like telephone 1-to-2 splitter. They are only made in Asia area.
Essentially, as kenredman already mentioned, only 2 pairs, out of 4 pairs, are being used in 10/100Mbps networking. You can use the 2 unused pair for another network.
Caution: For 1Gbps networking, all 4 pairs are used. Hence, no more spare wires.
Another caution: Some off the wall applications may use the spare wire(s) for other connections, such as telephone signal, audio, etc. If you do use an already installed Cat 5 wire, do check it out fully, in case you want to make modifications.

[chasrome]

dg 1261 answered my question nicely with the link (picture) he provided and scaisson provided new and good info on WHY one would prefer using a switch instead of a splitter. This is just what I needed to proceed with my project. Many thanks.