U can see if the jack is ethernet or not buy plugging in a ethernet cable or phone cable. If the plug can't fit the ethernet cable then its a phone jack.
Ethernet power line may not always working depending on how the electrical system is hooked up in your house. I know some houses have the electrical system hooked up weird and the powerline system doesn't work.
Best way to just to run an ethernet cable to the router/switch if you find that the plug in your room isn't a ethernet jack.
RS meet at BoaTurbo's house
