I have made these cords up before, this cord only uses 2 conductors so a length of Cat3 (station wire) 3 pair or less would be more than enough. Looking straight at the jack end with the tab facing down the pins are numbered from right to left, starting at 1 from the right to 4 or 8 depending on whether it is RJ11 or RJ45. On the RJ11 end pin 2 is red and pin 3 is white,on the RJ45 end pin 1 is red and pin 2 is white. That's it all you need is a crimper and the ends.