The Acronym Soup of Twisted-Pair Copper Cabling

The Acronym Soup of Twisted-Pair Copper Cabling

The Acronym Soup of Twisted-Pair Copper Cabling

Balanced twisted-pair copper cabling systems comprise a significant portion of today’s LAN infrastructure, providing the means to connect end devices throughout facilities – from computers, phones and wireless access points to surveillance cameras, to access control, digital displays and even LED lights. These cables also deliver power to devices via power over Ethernet (PoE) technology that can deliver up to 90 Watts over the same twisted pairs that transmit data, eliminating the expense of deploying separate AC power circuits.

While twisted-pair copper cables have come a long way over the past few decades, they all come in a variety of categories and different ratings that are represented by a range of industry acronyms. Let’s take a look at the various categories and explain some of the more common acronyms to help you identify the right cable for your project.

More than One Way to Skin a Cat

Twisted-pair copper cabling categories define various performance levels. The first official standard-based category was Category 3, which was ratified in 1991 by the Telecommunications Industry Association (TIA) and supported 10 Megabits per second (Mb/s) transmission to 100 meters at an operating frequency of just 16 megahertz (MHz). Since that time, twisted-pair cabling has advanced to reduce crosstalk and operate at higher frequencies to support faster transmission speeds.

Category 5e was ratified in 2001 to support 1000 Mb/s at 100 MHz, which was followed by Category 6 just a year later with more headroom and an operating frequency of 250 MHz. With proper verification, some higher-quality Category 5e and Category 6 cabling systems can support higher speeds of 2.5 or 5 Gigabits per second (Gb/s) to 100 meters, with the potential to support 10 Gb/s to shorter distances of about 50 meters or less.

Ratified in 2009, Category 6A is the highest performing twisted-pair copper cabling for use in the LAN, supporting 10 Gb/s to 100 meters at an operating frequency of 500 MHz. While Category 6A has been around for more than a decade and is recommended by industry cabling standards for all new installations, it is still gaining market share. Category 3 has pretty much gone by the wayside, but Category 5e and 6 are still installed for some LAN applications where 10 Gb/s speeds are not necessary. However, Category 5e and Category 6 are losing market share as drivers such as IoT, high-throughput Wi-Fi and high-resolution video require and increase adoption of Category 6A.

Know Your Cable Jacket Ratings

Twisted-pair copper cables are also designated by a variety of acronyms that define cable jacket ratings specified by codes such as the National Electric Code (NEC) and certified by safety certification companies such as Underwriters Laboratories (UL). Cable jacket ratings are primarily used to distinguish the ability of a cable to resist fire or limit the release of smoke or toxic fumes that can occur when jacketing materials such as polyvinyl chloride (PVC) burn. The most common cable jacket ratings for twisted-pair copper cables are described below.

  • CM—Communications Multipurpose cables are general-use cable for environments that do not require a specific fire rating, such as for patch cables used for equipment connections.
  • CMR—Communications Multipurpose Riser cables, or riser-rated cables, have a flame rating that prevents the spread of fire in risers that traverse from one floor to another. Riser-rated cables are therefore deployed in pathways or shafts that extend vertically through a building.
  • CMP—Communications Multipurpose Plenum cables, or plenum-rated cables, feature low-smoke PVC jacketing materials that restrict flame propagation to more than 5 feet and limit smoke emissions. Plenum-rated cables are required in air-handling spaces such as above a dropped ceiling or in a raised floor.
  • LSZH—Low Smoke Zero Halogen cables, sometimes designated as LS0H, have a high flame retardance and resistance and are typically required for use in plenum spaces outside of North America but may be required in certain harsh and industrial environments such as nuclear power plants.
  • LP—Limited Power cables can be CM, CMR, CMP or LSZH rated. Typically designated as an “-LP” suffix, such as CMP-LP, these cables have been certified by UL to indicate that the cable can carry it’s specified power current rating in worst-case scenario installations without exceeding its temperature rating. LP-rated cables are primarily designed for use in higher-power PoE (above 60 W) applications that can cause heat rise in larger bundles where cables can’t effectively dissipate heat. Using an LP-rated cable in these applications can prevent needing to limit bundle sizes as required by the NEC.

Unlike the category of a twisted-pair copper cable that defines the performance level and is typically specified by design engineers based on application requirements, cable jacket ratings are required by local building codes. Local codes are required by law and authorities having jurisdiction (AHJs) inspect cabling to ensure compliance. Not meeting the code requirement for cable jacket rating can put people and property at risk, prevent a building from receiving a certification or occupancy, and require cables to be replaced. Failure to comply with the code can even result in fines and legal ramifications. It’s therefore important to understand the local code requirements for every installation.

In an Industry Full of Acronyms, Vextra is Here to Help

In addition to acronyms that describe cable jacket fire ratings, the information communications technology industry is one that is filled with acronyms—from acronyms that identify spaces, units of measure and professional certifications, to those that identify components, services, equipment and other common industry terms and technologies.

While many acronyms can cause confusion, especially for those new to the industry, there are resources to help get you up to speed. TIA cabling standards such as the TIA-568 series of technical standards for commercial building cabling include a list of acronyms and their definitions. Installation guidelines such as BICSI’s Information Technology Systems Installation Methods Manual (ITSIMM) also include a detailed and comprehensive glossary of industry acronyms.

The good news is that Vextra Technologies offers the cable ratings you need for your project. And even if you don’t know all your acronyms, Vextra’s excellent customer service will assist you through the ordering process to ensure you get the right cable for your specification and code compliance.



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