6 Things to Consider When Choosing CATx Ethernet Cables

While for most applications, CAT6A is currently the recommended standard, there may be some cases in which you could still benefit from choosing CAT5e or CAT6, or even CAT7 or CAT8. But, in most cases, CAT6A still wins hands down.

In this article, we first give you an overview of each type of CATx cable. Next, we cover six things you should consider when choosing your CATx cable: bandwidth, speed, crosstalk, maximum length, visual difference, and cost.

What is CAT5e Cable?

CAT5e, also known as Category 5e or Category 5 Enhanced, is a network cable standard ratified in 1999. CAT5e offers significantly improved performance over the old CAT5 standard, including up to 10 times faster speeds and a significantly greater ability to traverse distances without being impacted by crosstalk. CAT5e cables are typically 24-gauge twisted-pair wires, which can support Gigabit networks at segment distances up to 100 m.

What is CAT6 Cable?

CAT6, derived from Category 6, came out only a few years after CAT5e. CAT6 is a standardized twisted-pair cable for Ethernet that is backward-compatible with CAT5/5e cable standards.

Like CAT5e, CAT6 cables support Gigabit Ethernet segments up to 100 m, but they also allow for use in 10-Gigabit networks up to 55 m. At the beginning of this century, CAT5e typically ran to the workstations, whereas CAT6 was used as the backbone infrastructure from routers to switches.

What is CAT6A Cable?

CAT6A Ethernet cable offers 10 times the network speed of CAT6 and twice the bandwidth. In fact, it has enough bandwidth to accommodate automation, IoT, and artificial intelligence systems, which are becoming increasingly common in manufacturing and other sectors. CAT6A cabling supports 10-Gbps Ethernet runs at full 100 meters as well as NBASE-T multi-gig applications. It also offers improved thermal properties for Power over Ethernet (four-pair PoE is close to 100 watts).

What is CAT7 Cable?

CAT7 first appeared in 2010, and it supports a maximum bandwidth of 600 MHz by using more shielding. CAT6A and CAT7 shielded twisted-pair cable both support 10 Gbps, and, in practice, perform identically, although CAT7 supports more bandwidth. CAT6A costs less and is less bulky than CAT7, so it is easier to terminate. CAT7 is constructed of S/FTP (screened/foiled twisted pair) cable, which has four individually shielded pairs and an outer screen braid around all four pairs. While CAT6A is ANSI/TIA 568 recognized, CAT7 is not as of this writing. CAT7, however, complies with ISO/IEC 11801.

What is CAT8 Cable?

The next cable level is CAT8, which is currently available and TIA recognized. For the most demanding applications, such as in data centers, CAT8 cable supports speeds of 40 Gbps and bandwidth of 2 GHz at distances of up to 30 meters or 10 Gbps at distances of up to 100 meters. CAT8 also has enhanced shielding for faster data transmission with fewer errors. CAT8 wraps each twisted pair in foil to practically eliminate crosstalk and achieve higher transmission speeds.

Below is a comparison chart for currently available CATx cables.

To make this information easier to digest, listed next are six things to consider when choosing CATx cable.

1. Bandwidth

The main difference between CAT5e and CAT6 cable lies within the bandwidth the cable can support for data transfer. CAT6 cables are designed for operating frequencies up to 250 MHz, compared to 100 MHz for CAT5e. This means that a CAT6 cable can process more data at the same time. Think of it as the difference between a 2- and a 4-lane highway. On both, you can drive the same speed, but a 4-lane highway can handle much more traffic at the same time. CAT6A doubles this bandwidth to 500 MHz, similar to creating an 8-lane highway. CAT7 and CAT8 support even more bandwidth (600 MHz and 2000 MHz, respectively).

2. Speed

CAT5e and CAT6 can handle speeds of up to 1000 Mbps, or a Gigabit per second at distances up to 100 m. Because CAT6 cables perform up to 250 MHz, which is more than twice that of CAT5e cables (100 MHz), CAT6 can additionally support speeds up to 10 Gbps, but at a shorter maximum distance of 55 meters. However, as internet connections speeds increase to 10 Gbps and beyond at distances up to 100 meters, this is no longer sufficient for the emerging internet speeds. Looking to the future, it is wise to make sure your cable will support these upcoming speeds. CAT6A and CAT7 support speeds up to 10 Gbps, and CAT8 handles up to 40 Gbps, and are good choices for greater speed.

3. Crosstalk

All CATx cables are twisted-pair cables. They use copper wires, with typically 4 twisted pairs (8 wires) per cable. In the past, the 250 MHz performance provided by CAT6 was often achieved by using a nylon spline in the wiring, which isolated each of the four twisted pairs, making the cable rigid. Today’s CAT6 cables are more flexible, using other methods to reduce noise.

Regardless of whether a spline is used, CAT6 features more stringent specifications than CAT5e for crosstalk and system noise. Not only does CAT6 provide significantly lower interference or Near-End Crosstalk (NEXT) in the transmission compared to CAT5e, it also improves Equal-Level Far-End Crosstalk (ELFEXT), Return Loss (RL), and Insertion Loss (IL). The result is less system noise, fewer errors, and higher data transmission rates.

CAT6A takes this one step farther: it eliminates Alien Crosstalk (A-NEXT) completely. Why is keeping crosstalk to a minimum so important? Using good-quality cable prevents connected interfaces from dropping or connecting randomly, or experiencing sudden loss of connectivity. Superior cable also ensures consistent, good-quality traffic. If wire twists in a cable are inconsistent or inaccurately spaced, crosstalk and poor performance result. CAT7 and CAT8 allow even less crosstalk than CAT6A for superior performance.

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