On Feb 28, 12:26, William S. wrote: Cat5 and Cat5e are UTP (unshielded). There is an equivalent shielded (STP) cable but it's a slightly different impedance so it's not Cat5 standard. No, there isn't an official colour code, though many sites have a local convention. Ours is to use black for serial, purple for crossovers, yellow for student network, pink or brown for telecomms, and other colours ad-hoc to distinguish various subnets in areas where more than one is in use. Where I worked before, the code was grey normal network purple crossed cable orange uplink cable, not crossed but connected to one that is yellow student network in a staff area (or vice versa) pink management network green telephone connection blue ISDN connection red temporary connection -- do not touch black serial connection -- Pete Peter Turnbull Network Manager University of York