Networking in a house

My question here is not directly related to the networking problem of a computer. My friend has 2 computer connected to a router with cables as both of them are in 2 rooms just next door. Now he is moving to a new townhouse of 3 -4 years old in which the computers are placed on different levels. He is thinking whether it is possible to maintain wired networking instead of using wireless for security reasons.

I help him to determine whether wired networking is possible. In the new house I house the spots where he wants to put the computers have RJ45 wall jacks with a 5e mark on them. Also, I found outlets in other rooms. Outlets in the house have 2 color, white and blue. The spot he would put the cable modem and router has 2 jacks on the same outlet together with the TV outlet as well. I tapped my network tester, the remote in one of them and looking for some connected signals. But I found the connection #4 is ON and even brighter than if it is connected with my master unit. I did the same test and found all jacks have the same situation. I open one of the wall outlets and found that the 5e cables also have 2 colors corresponding to the color of the jacks. But I I could not find where are the other ends of these cables in the house.

Outside the townhouse, I found a box labelled "telecommunications". I did not open it but thinking whether all the other ends of networking cables are there. My questions are why these cables carry some power? Are the other end of all cables are in the box outside?

Probably
http://www.swhowto.com/

Power over Ethernet maybe? You'll definitely need to trce the other end of the cables.

http://en.wikipedia.org/wiki/Power_over_Ethernet

Another thought occurred to me, that those cables may have been for a home security system, which is why they appear to terminate in that box. If that is the case, they probably are Power over Ethernet, and would have been used to both power and transfer data from security cameras.

SuperSparks, this is a townhouse vacant for a while. I don't think it has monitored security right now. My friend told me that the cable tech will come on 28th to connect the cable and Internet and I'll wait to see any new developments. Thanks.

Even though it may not have security in place right now, there may still be equipment connected that is supplying power to the connections. You should use a voltmeter to check for any voltages on the connectors before connecting any new network equipment. After that, you may want to invest in a cable tracer tool to find out which wires go where.