In 1973, Xerox PARC researcher Bob Metcalfe invented a high-speed networking system called Ethernet to allow computer workstations, servers and printers to share data and resources. Today, Ethernet connects hundreds of millions of devices in homes and businesses. In this article, we explain the Ethernet cable types that form the basis of many wired networks.
If you are buying Ethernet cable for the first time, focus on these four features and you'll make a good decision. Other factors are worth considering in certain circumstances so if in doubt, read on.
We know you have many brands to choose from. On the surface, they may all seem alike. It's what you don't see that makes the difference. With Tripp Lite, you get solid engineering, proven reliability and exceptional customer service. All our products undergo rigorous quality control before they are offered for sale, and independent testing agencies verify our products meet or exceed the latest safety and performance standards. Our commitment to quality allows us to back our products with industry-leading warranties and responsive customer service. It's the Tripp Lite difference. Ethernet Cable CategoriesThe "Cat" in Cat5e, Cat6, etc. is short for "Category." Network cables are divided into categories based mainly on bandwidth (measured in MHz), maximum data rate (measured in megabits per second) and shielding.
Bandwidth vs. Data Rate Data Rate and Bandwidth are related terms but they are not the same. Higher frequencies carry more 1s and 0s, allowing more bits of data to be transmitted per second. Cat5 cables have a one-to-one relationship between bandwidth and data rate: 100 MHz cable can transmit 100 Mb per second. Higher Category cables such as Cat8 encode the data so more bits can be transmitted in the same amount of time. Frequency (and therefore data rate) can be increased by increasing the gauge of the conductor wires, adding more twists to the conductors, or adding shielding to each pair of conductors.
What type of Ethernet cable should I buy for my home network?
The further a signal has to travel along a cable, the more it will degrade (a process known as attenuation) until it reaches the point where it can no longer be detected, or is too distorted to be interpreted by the receiving device. Attenuation can also be caused by noise due to electrical currents and radio frequencies. Cables with shielding to minimize noise will work reliably over greater distances.
The maximum length of a Cat5e or Cat6 Ethernet cable is about 295 ft. (90 m), plus up to 16 ft. (5 m) of patch cable on either end, for a total of 328 feet or 100 meters. Beyond this, the signal begins to degrade, reducing the speed and reliability of the connection. Good quality cable can support runs in excess of 100 meters but data transmission speed may be reduced. Higher data rates can also be achieved over shorter distances.
Ethernet cables made from four twisted pairs are terminated using an 8-pin RJ45 connector. Older telephone cable based on two twisted pairs typically use RJ11 connectors. The terms 8p8c (Eight Position, Eight Contact) and RJ45 are often used interchangeably but 8p8c actually refers to a category of connectors of which RJ45 is one. The modern RJ45 Ethernet connector is the most common example of an 8p8c connector. GG45 (GigaGate 45) or ARJ45 (Augmented RJ45) is a connector originally developed by French cable company Nexans for use with Cat7 cable. GG45 connectors have 12 pins in total, 8 providing backwards compatibility with Cat6, and an additional 4 pins providing support for frequencies of up to 600MHz.
M12 coded connectors are found on Ethernet cords designed for industrial applications. These cables are often exposed to vibration, extreme temperatures and moisture. The threaded connectors are designed to provide a waterproof and secure connection.
Why is an Ethernet cable connector called RJ45? Connector Styles
Molded connectors are permanently attached to a cable using a manufacturing process called over-molding. The connector and cable are covered with a thermoplastic or silicon material to form one solid piece called a boot, making the cable more durable and able to withstanding a high number of insertion cycles.
Snagless connectors have a modified boot that protects the connector's lock from being accidentally snapped off. Snagless cables are typically used in situations where the cable is frequently connected and disconnected, such as a laptop-to-wall network connection.
Cable Styles
Slim and Ultra-Slim Cables
Flat Cables A flat cable is a good choice if you need to carry an Ethernet patch cable around in your laptop bag. It is strong, light and will not tangle easily. Its flat shape makes it ideal for cable runs under carpet and behind baseboard.
Solid Core Cables In situations where a cable is repeatedly flexed or connected and disconnected, choose a stranded cable. For horizontal cable runs not subject to repeated movement, or for Power-over-Ethernet (PoE) and outdoor applications, use solid core cable. Armored Cable
What is a Crossover Cable?
Cables with T568A wiring on one end and T568B on the other are known as "crossover" cables. You can identify a crossover cable by comparing the order of wires on each end. If the wires are the same on each end (regardless of which pin configuration is used), it is a "straight-through" cable. If they are different, it is a crossover cable. Nowadays, most Ethernet switches and routers have a feature called auto-MDIX, which can detect which type of port or cable (crossover or straight-through) is connected and swap the transmit and receive pins accordingly, removing the need for crossover wiring.
One of the factors limiting the length and data rate of Ethernet cable is the size of its conductors. Electrical current encounters greater resistance when transmitted over thinner wire. The larger the conductor, the easier it is for the electrons to pass through it resulting in lower resistance, lower signal loss and greater transmission distance. The diameter or gauge of a cable's conductor is referred to using American Wire Gauge (AWG) standard sizes. For example, a 24 AWG solid conductor is 0.0201 inches in diameter. A 28 AWG conductor is 0.0126 inches in diameter, almost half the size. That's right, the smaller the AWG gauge, the bigger the conductor diameter.
Conductor gauge affects a cable's performance but is typically not the most important factor. Shielding and twist rate have more impact on signal strength and quality.
Ever wondered why an Ethernet cable uses twisted pairs of conductor wires? Early telephone lines were susceptible to interference from electrical wires that often shared the same utility poles. Engineers discovered that by swapping the position of the telephone wires every few poles (i.e. the left line became the right and the right became the left), they could reduce distortion. This technique of wire transposition was the first use of twisting, albeit with a very loose twist rate of about six turns per mile. In 1881, Scotsman and AT&T co-founder Alexander Graham Bell used the same technique to create the first twisted pair. By the turn of the 20th century, twisted pair cable was widely used for transmission of signals on voice telephone lines.
Today, twisting conductor pairs is a common way to minimize signal interference and crosstalk, and increase cable performance. The twist rate or "pitch" is usually measured as the number of twists per inch or centimeter. Twist Rate is not specified in the IEEE or TIA category cable standards and is left to the manufacturer to decide. Cat5e typically has a twist rate of 4-5 twists per inch whereas Cat6 cables have a twist rate of 5 or more twists per inch. To further reduce crosstalk, not all conductor pairs in a cable will have the same twist rate.
Jackets protect the cable's conductors from physical damage, moisture and ultraviolet light. When installing cable in walls, ceilings and under floors, it is important to use cables that meet the local code requirements (usually based on the NFPA's National Electric Code). The three basic ratings for both cable types are general purpose, riser and plenum-rated.
PoE allows both power and data to be delivered over a single, solid core category cable. This makes it ideal for networking IP devices like security cameras, access control readers, wireless access points (WAPs), sensors and lighting that require DC power and a data network connection. PoE gives you the flexibility to install devices where you need them without having to worry about access to AC power. Further Reading
UL has developed a Limited Power Certification for Power-over-Ethernet (PoE) applications. The LP designation, first introduced in 2015, indicates that a cable has been tested under "reasonable worst case installation scenarios" and is capable of carrying the stated current without exceeding the temperature rating of the cable. The LP designation is particularly important in PoE++ applications where power exceeds 60 watts. Outdoor CableExterior-grade CMX Ethernet cable is waterproof and resistant to drying and cracking after long-term exposure to the sun. It can also be buried in the ground without a conduit. Also consider cable and hooded connectors with an IP68 rating. Plenum Spaces and RisersPlenum is the space above or below a room that provides a way for air to return to a building's HVAC system. A riser is a vertical shaft between floors for electrical wiring, water pipes, and voice or data cabling. In the event of a fire, it's critical that cabling in these areas does not promote the spread of smoke and toxic fumes. When selecting cable to run through plenum or risers, look for products with a jacket rating of CMP (plenum) or CMR (riser). These cables have a higher degree of fire resistance and emit fewer toxic fumes compared to general purpose CM or CMG rated cables. In the US, the NFPA's National Electrical Code (NEC) guidelines requires CMP or CMR cabling for plenum or risers and compliance may be a contractual or legal requirement. Because CMP cables have a higher fire resistance, you can use CMP in risers but you cannot use CMR cable in plenum spaces. Anti-Bacterial CablesThe jacket on these cables is constructed using an antibacterial material that is 99.9% effective in inhibiting Escherichia coli (E. coli) and Staphylococcus aureus (staph). This added protection makes these cables an ideal solution for high-touch applications and in environments where bacterial infection is of particular concern, such as medical facilities, schools, process manufacturing and restaurants/kitchens.
What is the difference between Cat5 and Cat6? Should I upgrade from Cat5e to Cat6? Are Cat8 cables worth the extra money? Can you mix Cat5 and Cat6 cable in a network? Are all Cat6 cables the same? Do cheap cables work just as well?
We know you have many brands to choose from. On the surface, they may all seem alike. It's what you don't see that makes the difference. With Tripp Lite by Eaton, you get solid engineering, proven reliability and exceptional customer service. All our products undergo rigorous quality control before they are offered for sale, and independent testing agencies verify our products meet or exceed the latest safety and performance standards. Our commitment to quality allows us to back our products with industry-leading warranties and responsive customer service. It's the Tripp Lite by Eaton difference. |