RJ45 Network Cable 1-to-2 Female-Female Spliter Coupler

The ascii art picture given in the description is actually wrong -- you should never use this unmodified as a branch to two PCs and then also have one branching to two switch ports on the other end, because the two switch ports will interfere with each other and you'll get no connection at all.

In standard form, you can just use it to connect two computers, only one of which will be turned on at any one point.

There is something you can usefully *modify* this product to, though, which will allow you to have two full 100M ethernet connections running over a single 8-pair cat5. You'll need two of this product (and a couple extra just in case you screw one up), a pair of small scissors, and an ethernet cable.

First, open up the outside case. Then, remove the innards of all three connectors (pry them upwards by the cabling until it unlocks, then insert an RJ45 to get them out if the wires are still hooked inside). Use the scissors to cut off one of the 'branch' connectors, so you're left with just a cable that's straight through from one to the other connector. Now bend the pins on the removed connector up and over so you can pull all the wires out from the plastic bit and discard the wires. Then, carefully bend and remove the wires for pins 4,5,7,8 (on your ethernet cable, the side that has the orange wires is the one where you start counting from pin one) from one of the connectors, and put them back in the empty plastic shell at positions 2,1,3,6 respectively. Reassemble with the two connectors with 1/2/3/6 connected in the double part and the one with all 8 connected in the single part.

Make two of these, put one at either end of a long cable, and you've got two separate network connections. At one end plug both into a switch, at the other, both into a PC, ie:

two switch ports ====>------------<=== two PCs

If you want to test the pinning of the modded splitters, use 4 previously tested short cables to connect to an RJ45 connection tester (also available on this site cheaply) like so:

tester ----<======>---- tester remote

If you match up the ports in the middle correctly, you should see an unbroken cable on the tester.


Pinning of what you should end up with:

Main A B
1 1
2 2
3 3
4 2
5 1
6 6
7 3
8 6

I also intend to modify one of these to a power-over-ethernet injector. Free bonus suggestion.