Can I use Cat5/Cat6 instead of phone cables

I wonder if I can replace the phone cable that connects my DSL router to the box outside the building with a Cat5/6 cable.

The phone cable in use has only two wires inside it. So, I was wondering if I can use two wires from the Cat5/6 cable for carrying out the signal from the box to the router. I heard using Cat5e and Cat6 cables is more beneficial than the ordinary phone cable because Cat5e/6 cables handle interference better.

Also, are there any benefits to using Cat6 over Cat5 in this case? If what I said is possible, which two wires inside the Cat cables should I use? From my understanding I will use two of the wires on the Cat cable and connect them directly to the box outside after stripping them. Then, on the other side I will put an RJ11 connector and put those two wires that I used on the box to the middle pins of the connector.

Is that right? Also, will I need to cut any of the other six wires off? Which other wires should be inside?

Solution 1:

Blue and Blue white are center pair too. If you punch everything down into an RJ 45 jack (ehternet jack) then an RJ 11 (phone jack 2 pair) can plug into an RJ 45 jack and use center 2 pair. Lines up perfectly. Then the line can be used for RJ 45 or RJ 11 purposes. Good Luck!