That cable is only 6 strand not eight strand as ethernet cable. It is also corroded.
You can use the old cable as a guide to help pull new cable.
Drop the DVR and the cameras in the garage can.
start planning on a new system.
Please read the
IP Cam Talk Cliff Notes and other items in the
IP Cam Talk Wiki. (read on a real computer, not a phone). The
wiki is in the blue bar at the top of the page.
Read,study,plan before spending money ..... plan plan plan
Doing it right the first time will save you money.
Test do not guess