Copper cables

How do differentiate them ?

What does that letters even mean ?


Have you ever wondered what does U/UTP CAT 5e or S/FTP CAT 6a means, well I’m going to help you out with that matter.

So for starters there are currently 7 categories of copper cables (9 if you count the updated versions Cat5e and Cat6a) from which we use 4 on a daily basis in our homes and offices.

The main difference between the cables are their performance and if they are shielded or unshielded.

You can use unshielded twisted pair for short cables/patches between computer, tv and router. The shielded twisted pair has higher performance and it’s best for long run or where the cable passes through areas of high electrical noise.

It’s pretty easy to differentiate them because in most cases there are tags on every meter of the cable with the length,type and manufacturer !

But one thing is to recognize the cable and another to understand why to use this cable. Before I start to “unfoil” what every category is for let’s discover what are the letters before the category for.

-      U/UTP - Unshielded cable, unshielded twisted pairs

-      F/UTP - Foil shielded cable, unshielded twisted pairs

-      U/FTP - Unshielded cable, foil shielded twisted pairs

-      S/FTP - braided shielded cable, foil shielded twisted pairs

Where: TP = twisted pair, U = unshielded, F = foil shielded, S = braided shielding.

There are different methods that can be used for shielding Ethernet cables. The most common is to place a shield around each twisted pair. This not only provides shielding for the cable externally, but also reduces crosstalk between the internal twisted pairs as well. Manufacturers can further enhance the performance by placing shielding around all the wires in the cable just under the cable sheath.


Now that we know that we can continue to the categories:


-      Cat-1:     This is not recognised by the TIA/EIA. It is the form of wiring that is used for standard telephone (POTS) wiring, or for ISDN.

-      Cat-2:     This is not recognised by theTIA/EIA. It was the form of wiring that was used for 4Mbit/s token ring networks.

-      Cat-3:     This cable is defined in TIA/EIA-568-B. It is used for data networks employing frequencies up to 16 MHz. It was popular for use with 10 Mbps Ethernet networks (100Base-T), but has now been superseded by Cat-5 cable.

-      Cat-4:     This cable is not recognised by the TIA/EIA. However it can be used for networks carrying frequencies up to 20 MHz. It was often used on 16Mbps token ring networks.

-      Cat-5:     This is not recognised by the TIA/EIA. This is the network cable that is widely used for 100Base-T and 1000Base-T networks as it provides performance to allow data at 100 Mbps and slightly more (125 MHz for 1000Base-T) Ethernet. The Cat 5 cable superseded the Cat 3 version and for a number of years it became the standard for Ethernet cabling. Cat 5 cable is now obsolete and therefore it is not recommended for new installations.


-      Cat 5 cable uses twisted pairs to prevent internal crosstalk, XT and also crosstalk to external wires, AXT.


-      Although not standardised, the Cat 5 cable normally uses 1.5 - 2 twists per centimetre.

-      Cat-5e:     This form of cable is recognised by the TIA/EIA and is defined in TIA/EIA-568, being last revised in 2001. It has a slightly higher frequency specification that Cat-5 cable as the performance extends up to 125 Mbps.


-      Cat-5e can be used for 100Base-T and 1000Base-t (Gigabit Ethernet). Cat 5e standard for Cat 5 enhanced and it is a form of Cat 5 cable manufactured to higher specifications although physically the same as Cat 5. It is tested to a higher specification to ensure it can perform at the higher data speeds. The twisted pairs within the network cables tend to have the same level of twisting as the Cat 5 cables.

-      Cat-6:     This cable is defined in TIA/EIA-568-B provides a significant improvement in performance over Cat5 and Cat 5e. During manufacture Cat 6 cables are more tightly wound than either Cat 5 or Cat 5e and they often have an outer foil or braided shielding. The shielding protects the twisted pairs of wires inside the Ethernet cable, helping to prevent crosstalk and noise interference. Cat-6 cables can technically support speeds up to 10 Gbps, but can only do so for up to 55 metres - even so this makes them relatively long Ethernet cables.


-      The Cat 6 Ethernet cables generally have 2+ twists per cm and some may include a nylon spline to reduce crosstalk, although this is not actually required by the standard.

-      Cat-6a:     The “a” in Cat 6a stands for “Augmented” and the standard was revised in 2008. The Cat 6a cables are able to support twice the maximum bandwidth, and are capable of maintaining higher transmission speeds over longer network cable lengths. Cat 6a cables utilise shielded which is sufficient to all but eliminate crosstalk. However this makes them less flexible than Cat 6 cable.

-      Cat-7:     This is an informal number for ISO/IEC 11801 Class F cabling. It comprises four individually shielded pairs inside an overall shield. It is aimed at applications where transmission of frequencies up to 600 Mbps is required.

So to make everything clearer the newer the technology the higher performance and stability over long distances !

Here is a table showing accurate speeds and lenghts for all the categories: 

Cat 3Unshielded10 Mbps16 MHz
Cat 5Unshielded10/100 Mbps100 MHz
Cat 5eUnshielded1000 Mbps / 1 Gbps100 MHz
Cat 6Shielded or Unshielded1000 Mbps / 1 Gbps>250 MHz
Cat 6aShielded10000 Mbps / 10 Gbps500 MHz
Cat 7Shielded10000 Mbps / 10 Gbps600 MHz

10BaseTUnshielded Twisted Pair100 metres
10Base2Thin coaxial cable180 metres
10Base5Thick coaxial cable500 metres
10BaseFFibre optic cable2000 metres
100BaseTUnshielded twisted pair100 metres
100BaseTXUnshielded twisted pair220 metres

In conclusion the buyer is always going to choose what Is best for the money they want to spend ! But now knowing all the differences while choosing the right cable you can choose the best quality/performance and price !