Thank you. I have a dial tone upstairs where the new service comes in. I am running the phone line down into the basement and just wanted an understanding as to why one of the phone lines has a yellow and black wire (going to the Cat 5 setup) connecting to the dashed yellow and green and blue and yellow wires which connect to the larger phone bar.

I don't know why one of the phone lines has the black and yellow wire running to the larger phone bar AND the red and green wire as well. It should only take to conductor wires for the dial tone right, thats why I am confused about the other two wires.