The ethernet network connectors don't work too well, I have tried a few and none worked. Get a longer cable, they are not expensive if you get it online.
I agree, which is why I recommended a longer cable. Most couplers have loose fittings which can cause you to lose the connection even though the cables still look attached to the coupler properly. The ones I used worked, but I only used them until I could get a longer run in place.