I just checked, the jack that I have one the wall is a network jack and they use cat5e wire, however it'll work for phone jack as well, so it can be used as phone or internet, it is possible to use both over same wire however it is not recommanded as it'll have interferances to the network when the phone rings, and have possibility to damage your network card if you use phone and network over same wire. if you don't use phone, you could wire it for network using same wire and all you need to do is to have it wired correctly at the entertainment centre.
Even though it is cat5e cable, it is prewired to work with phone, not network. My bell internet currently is going over cat5e and without problem. If you use rogers internet, and don't have land line for phone, you could change them to use for network.
