Your local building codes might have a.
How to run cat5 cable from one floor to another.
How to run a second ethernet jack in another room.
The one shown here is a cat 5e keystone jack.
Then to the opposite action have one person feed the cables down through the hole to the destination while another person pulls the cable out from the wall.
The other module plugs into an ac outlet in the room where you want to add an internet port.
Run the wires through the holes above their respective rooms.
Using a coat hanger i was able to thread the ethernet cable through the space and over to another small hole in the ceiling where i was able to continue the path down the far wall.
Most of the hard work is done.
You can pay more for in wall rated cables including plenum cables encased in a fire retardant jacket.
When you ve run all the wires up to the attic then bring each one to the hole that it has to feed down through.
All you need to do now is to install the box into the wall and feed the wire to it.
If you have another floor to go you can follow the same steps in the same order.
Most homes feature a single centrally located point for connecting to the internet usually in the form of a wall plate.
Pull the e thernet cable to its destination and you re set.