We are all familiar with Ethernet cables and what they look like, after years of working with computers and other wired devices in our homes and offices. The newer standard, Cat6 is capable of higher data transfer speeds and does a better job of protecting you against crosstalk and other interference.
Types of Ethernet cable
When replacing a cable, you ideally want to match the cable to the type of network (Cat5e or Cat6) already installed, although Cat6 cable is backwards-compatible with Cat5e.
That’s not the only distinction you’ll have to understand since Ethernet cabling is commonly labelled as “UTP,” “FTP” or “STP,” even newbies can now easily guess that “TP” stands for “twisted pairs.” But that still leaves the “U, “F” and “S” to decipher. Let’s see how easy we can make this.
Unshielded Ethernet Cable
Some environments are prone to greater-than-normal amounts of Electromagnetic Interference (EMI), so there are cables designed to provide protection against interference. The protection is called shielding,
Normal twisted-pair Ethernet cables will usually perform just fine without extra shielding when used in home and small office networks that don’t have lots of equipment that will cause EMI. Since it’s unshielded (“U”), it’s referred to as “unshielded twisted pair” cable (or UTP for short).
Shielded Ethernet Cable
We now consider FTP and STP, which are each shielded Ethernet cables. The terms can be a bit confusing because they’re often used interchangeably, and each has extra components inside the cable in order to protect signals from interference. However, there is a difference between them.
FTP cable specifically uses a foil (“F”) shield wrapped around the outside of the twisted pair package and does not protect the pairs individually.
STP cable normally covers each of the twisted pairs separately with either foil or tightly-braided wire, with another layer of foil or braided shielding covering the entire conductor package. That makes STP cable fully shielded (“S”).
FTP or STP Ethernet cable choice
So how do you choose between them? An environment with lots of heavy equipment, high-powered electrical motors and fluorescent lighting is likely to generate enough EMI to require the use of STP Ethernet cable.
Several commercial situations definitely call for FTP Ethernet cabling. When you need the fastest data transfer possible or when your cable must cover long distances, the premium performance of FTP cable will make an enormous difference. It not only eliminates most EMI but also prevents alien crosstalk that occurs at high speed between twisted pairs.
FTP cable is useful in keeping signals secure from “eavesdropping” because the extra shielding prevents the signals from escaping.
Finally, a little extra information for the sake of completeness. If you’re confronted with a choice between straight-through or crossover cables, you’ll almost always want the straight-through cable. Crossover cables have some of the conductor wires reversed at the connectors but are only used these days to connect to very old computers or network switches.
For more information contact Ryan Danvers at ABACON IT on 072 601 2858.
Author: Ryan Danvers/ABACON IT