I have a four conductor shielded cable that I have a question about. Basically the device I am using this cable with has five prongs it. Data "Tx + and -", data "Rx + and -", and "shield". Well the cable I am using has a fifth uninsulated conductor in it. But it's not made out of copper, I think it may be steel cable, but I am not sure. I am wondering if I should connect this fifth conductor to the "shield" prong on my device. Or is it for structural support? What is it designed for? Also, there are some yellow fibers in my cable, what are those for?