Category 5 or 6 Ethernet Cable
You will need to purchase a Category 5 or 6 Ethernet cable to connect your Ethernet adapter to the wall jack. Use only a cable rated for Category 5 network use. Do not attempt to use a telephone cord or Category 3 cable with your Ethernet adapter.
The images below show the difference between Ethernet cables and phone cables. The plug of the Ethernet cable is about four millimeters (~ 1/8 of an inch) wider than the plug of a phone cable. An Ethernet cable also has eight wires while a phone cable only has four or sometimes two.