A Complete Guide to Cat5 & Cat5e Cable

There are numerous categories of Ethernet cable sold online in the UK. When people ask, ‘what is Cat5 or Cat5e cable?’, they are usually asking what the difference is between the two, and how they relate to other widely used standards. In this guide, we will address this and other frequently asked questions about various wired internet, Ethernet, and network cable types.

We aim to provide clear and straightforward information about Cat5 and Cat5e cables. We will explain what these standards mean, give examples of their common uses, and talk about the various types, lengths, specifications, and prices.

By the end of the guide, you should have a clear understanding of Cat5 cable and Cat5e cable. You will also know about the various connectors, testers, speeds, cable lengths, and the colours associated with them, and be better placed to decide which type of Ethernet cable best suits your workplace needs.

Cat5 and Cat5e are two common classifications of Ethernet or network cabling. The Cat5e specification came into widespread use after 2001, before which Cat5 had been the latest standard.

Cat5 stands for Category 5 cable, while Cat5e stands for Category 5 Enhanced (or Enhanced Category 5). Cat5e specs offer a significant upgrade in terms of general performance and faster data transfer speeds than the earlier Cat5 versions.

However, basic Cat5 is often sufficient for those on mid-speed broadband connections, who do not need the fastest data transfer rates available.

Cat5 cable specifications dictate it should be able to handle data transfer over Ethernet networks at frequencies (also known as bandwidth, or data-carrying capacity) of up to 100 MHz. Cat5e offers superior performance and is rated for frequencies of up to 350 MHz. This is due in part to its stricter performance requirements for things like crosstalk (interference between individual wires), attenuation and return loss.

In day-to-day practical terms, most users will chiefly be interested in what internet speeds or data transfer speed each standard support.

Cat5 cable is designed to carry data over a wired network connection at speeds of 10 Mbps (Ethernet) or 100 Mbps (Fast Ethernet). You will often see this written as 10/100 Ethernet when shopping for Cat5 cable online. This means that if your local network or incoming internet connection runs at between 10-100 Mbps (also known as a 100BASE-T network), Cat5 Ethernet cable should be able to handle the required data throughput at full speed, with no loss or delay.

Cat5e cable spec dictates that it can carry data over a wired connection at speeds of either 10 Mbps, 100 Mbps, or 1000 Mbps (equal to 1 Gbps, and thus usually referred to as Gigabit Ethernet). You will often see this written as 10/100/1000 Ethernet. This means that if your local network (or incoming internet connection) runs at between 10-1000 Mbps/1 Gb (also known as a 1000BASE-T network), Cat5e Ethernet cable should be able to handle the required data throughput at full speed, with no loss or delay.

In short, for transfer speeds above 100 Mbps, or bandwidth requirements greater than 100 Mhz, you should upgrade from Cat5 to Cat5e cables or above. Note that all Cat5e cable is fully backwards compatible with any devices or ports (jacks) that support the use of a Cat5 wired Ethernet connection.

In basic construction terms, there are two main types of Cat5 and Cat5e cable, namely stranded core and solid core. These terms refer to how the data-carrying wires, or conductors, that make up the inner core of the cable are arranged.

Solid conductor (solid-core) Cat5/Cat5e Ethernet cable tends to be used where longer runs need to be set up to achieve a more reliable and stable permanent wired network. This is more common in office buildings and other professional setups. Applications that involve running outdoor Cat5 cable, or passing it through sections of wall, will often benefit from the use of solid-core wiring.

Stranded conductor (stranded core) Cat5/Cat5e Ethernet cable tends to be used for establishing shorter runs between temporary or easily movable wired networks. Small office networks, such as those linking computers to a router via a short Cat5e patch cable or similar will generally be fine using stranded Ethernet wiring. Most standard Ethernet patch cables at lengths of 50 feet or less will tend to have stranded conductors.

At first glance, you cannot necessarily tell whether a given length of Ethernet cable is stranded or solid without cutting through it to find out. However, stranded cable is usually a lot more flexible than solid core cable. Solid cables will often retain some degree of deflection for a while after being bent at a sharp angle.

Cat5e Cable Diagram

See to the right for a Cat5e cable diagram, showing the basic construction of different types of Cat5e Ethernet cables.

Note that they are typically manufactured as multi-twisted pair cables. They are usually constructed from four colour-coded pairs (so eight wires in total) per cable. Each pair consists of two wires twisted together to form a single strand, hence the term twisted pair wiring.

Shielded vs. Unshielded Ethernet Cable

In addition to the basic Ethernet cable standards and the stranded vs. solid designs, there are also other manufacturing specifications available for each type and category. These are commonly abbreviated as:

• U/UTP (Unshielded/Unshielded Twisted Pair): Neither the individual twisted pairs nor the cable has any additional shielding built-in. Only the basic protections - the standard insulation around each twisted wire, and the cable sheath itself - are present
• F/UTP (Foil/Unshielded Twisted Pair): While the individual twisted pairs do not have any additional shielding, the cable features an added layer of foil under the outer sheath
• U/FTP (Unshielded/Foil Twisted Pair): The individual twisted pairs each have their layer of additional foil shielding around them, but the cable only has the basic outer sheathing
• F/FTP (Foil/Foil Twisted Pair): Both the individual twisted pairs and the cable have an added layer of foil shielding around them

U/UTP is, therefore, the most susceptible to interference, signal noise, return loss, and attenuation, although the cable will be considerably cheaper to buy. F/FTP will offer the greatest protection against performance-limiting factors like crosstalk, but it will also be the most expensive type to buy.

The standard assembly for basic Cat5 cable is often U/UTP, while many high-quality Cat5e Ethernet cables are manufactured with at least some form of additional shielding built-in. This shielding helps to protect the carried signal from several forms of interference, minimising the risk of data corruption or network connection loss.

A shielded network cable is typically recommended over longer runs, for outdoor use, or where the wiring passes through walls where there is likely to be a good deal of other electrical connections nearby. An unshielded network cable is often sufficient over short indoor runs where there is less potential for crosstalk.

Cat5 and Cat5e cables are available in a wide variety of different lengths. In most cases, Cat5 patch cables tend to be chosen for reasonably short runs (100ft or less), especially if they are stranded core wires.

However, there are valid use cases for choosing longer runs of Cat5e wiring, in which case you can easily buy reels in lengths of 1000ft or more. Common pre-cut lengths you will see on sale at UK suppliers include 30cm/300mm, 50cm/500mm, 1m, 2m, 3m, 5m, 10m, 30m, 100m, 152m, and 305m.

In terms of widely available Cat5 and Cat5e cable colours, the most common are usually black, grey, or white. However, it is equally easy to find Ethernet cables in a much wider variety of colours including blue, green, orange, purple, red, and yellow.

Cat5 and Cat5e cable prices vary according to brand, quality, length, and materials, as well as the type and amount of any additional shielding included in the manufacture. The cheapest Ethernet cables in this category will generally be unshielded solid Cat5 varieties, while more expensive versions will usually be stranded and shielded Cat5e leads.

You can buy cables pre-made to certain lengths and fully terminated with an RJ45 connector at either end. However, it tends to be more expensive per foot (or per metre) to buy this way. For professional systems installers, it will often work out much cheaper to buy larger drums or reels of unterminated cable. You can then cut this to the required lengths and easily wire your connectors to the pinouts.