What Is the Most Common Type of Network Cable? Why Cat6 Twisted Pair Runs Most Business Networks

Look behind almost any desk, ceiling tile, or security camera and you will find the same thing: a round cable with a clear plastic plug on the end. So what is the most common type of network cable? It is unshielded twisted pair (UTP) Ethernet cable with an RJ45 connector, and in new commercial installations today, the most common category is Cat6.

That answer comes with some nuance. Older buildings are full of Cat5e, newer projects increasingly specify Cat6A, and fiber dominates backbones and data centers. This guide explains why twisted pair became the default, how the categories compare, and how to choose the right cable for a business network. Businesses looking for reliable network cabling services in Carson, CA can get professional guidance on selecting and installing the appropriate cabling for their network.

Table of contents

1. The short answer
2. What “most common” really means
3. Why twisted pair Ethernet dominates
4. Cat5e vs. Cat6 vs. Cat6A
5. Inside an Ethernet cable: pairs, RJ45 and wiring standards
6. Solid vs. stranded cable
7. Straight-through vs. crossover cables
8. Multigigabit Ethernet and Wi-Fi
9. Where fiber and coax fit
10. How to choose the right cable for your building
11. Common mistakes and misconceptions
12. Future trends
13. Key takeaways
14. FAQ

The Short Answer: The Most Common Type of Network Cable

The most common network cable is four-pair unshielded twisted pair copper cable, usually called an Ethernet cable. It connects computers, phones, printers, Wi-Fi access points, cameras, and switches in nearly every office, store, school, and home.

Within that family, Cat6 is the category most often installed today. Industry research describes Cat 6 as the most widely deployed category in the structured cabling market, anchored by its cost-effectiveness for 1G–2.5G office LANs. Another market report projects that the Cat 6 segment will hold the largest market share of 52.80% in 2026.

Key stat: Cat6 is projected to account for more than half of the structured cabling market by cable category in 2026, according to Fortune Business Insights. (Market research estimates vary between firms, so treat any single figure as an approximation.)

What “Most Common” Really Means

The answer depends on how you count. By number of connections, twisted pair copper wins easily, because every desk, phone, camera, and access point needs its own cable. By dollars spent, some reports put fiber ahead.

One research firm reports that fiber optic cabling solutions captured 68.5% of revenue in 2025, reflecting the copper-to-fiber migration across enterprise and data center verticals. Another estimates that copper cabling holds roughly 56% of the market. Those numbers conflict partly because firms define the market differently and partly because fiber projects, especially hyperscale data centers, involve expensive components in huge volumes.

For a typical business, the practical picture is consistent across sources. Copper remains dominant for horizontal cabling due to its cost efficiency and compatibility with PoE and Wi-Fi, while fiber handles backbone links. In other words, the cable reaching your devices is almost always twisted pair.

Why Twisted Pair Ethernet Dominates

Several advantages keep twisted pair at the center of business networks.

It is inexpensive and easy to terminate

Twisted pair costs less per foot than fiber, and the tools to terminate it are affordable. Jacks, patch panels, and patch cords are standardized and widely available.

It works with almost everything

The RJ45 port is nearly universal on network equipment. RJ45-style connectors are widely used with Ethernet cables such as Cat5e, Cat6 and Cat6a to connect network devices including computers, switches, routers and access points.

It carries power as well as data

Power over Ethernet (PoE) lets one cable run both data and power to cameras, phones, access points, and door hardware. That removes the need for a separate outlet at each device, which is a major reason copper remains the default at the network edge. Fiber cannot deliver PoE.

It follows a clear standard

Performance is defined by ANSI/TIA-568, which specifies official Ethernet cable categories such as CAT5e, CAT6, and CAT6A. The standard also sets the familiar distance limit: a 90-meter permanent link (horizontal cable in the walls and ceiling) plus up to 10 meters of patch cords at both ends combined.

It keeps getting faster on the same cable

Newer Ethernet standards have repeatedly squeezed more speed out of existing copper. That backward compatibility protects the money businesses already spent on cabling.

Cat5e vs. Cat6 vs. Cat6A: Which Is Most Common?

Each category is common in its own way. Cat5e has the largest legacy footprint, Cat6 leads current installs, and Cat6A is the fastest-growing choice for new commercial work. The complexity of an installation can vary depending on the building and cabling requirements, which is why businesses may wonder whether network cabling is hard to install correctly.

Cat5e: the legacy workhorse

CAT5E remains widely deployed in Gigabit networks and legacy commercial environments. Many buildings wired in the 2000s and early 2010s still run on it, and it still supports gigabit connections to full distance.

Cat6: today’s standard for most offices

Cat6 offers more bandwidth and better crosstalk performance than Cat5e. CAT6 cable is rated for a minimum bandwidth of 250 MHz according to the ANSI/TIA-568 standard. It supports gigabit to 100 meters and 10-gigabit on shorter runs. Its balance of cost and performance is why it dominates new office installs.

Cat6A: the growing choice for new commercial builds

Cat6A is increasingly specified for new construction and major upgrades. Enterprise campuses and healthcare facilities are systematically replacing aging Cat 5e runs with Cat 6A. It supports 10-gigabit at full distance and handles high-power PoE better than Cat6.

What about Cat7 and Cat8?

Higher numbers do not always mean better for an office. Cat7 uses non-standard connectors (GG45/TERA) and is not ANSI/TIA-recognized, making it impractical for modern RJ45-based networks. Cat8 has a narrow purpose. It is purpose-built for 25G and 40G short-reach data center cabling system links, not for running to desks across a building.

Category	Rated bandwidth	Typical top speed at 100 m	Where it’s common
Cat5e	100 MHz	1 Gbps (2.5 Gbps with 802.3bz)	Older offices and homes
Cat6	250 MHz	1 Gbps (5 Gbps with 802.3bz; 10 Gbps on shorter runs)	Most current office installs
Cat6A	500 MHz	10 Gbps	New commercial builds, Wi-Fi 6/7, high-power PoE
Cat8	2000 MHz	25/40 Gbps over short runs	Data centers only

For a deeper look at how copper compares to fiber and coax, see our guide to [the three main types of cabling](INTERNAL LINK).

Inside an Ethernet Cable: Pairs, RJ45 and Wiring Standards

Four twisted pairs

A standard Ethernet cable contains eight copper conductors arranged as four color-coded pairs: blue, orange, green, and brown. Each pair is twisted at its own rate to reduce interference from neighboring pairs and outside noise.

The RJ45 connector (technically 8P8C)

The plug on the end is almost always called RJ45, but that is a shorthand. Technically, the modular connector fitted to Ethernet cables is an eight-position, eight-contact connector, commonly described as 8P8C. Nevertheless, RJ45 remains the term most installers, network technicians and equipment suppliers use.

T568A and T568B

The order of the wires inside the connector follows one of two TIA schemes. From a practical standpoint, they perform and function identically in a modern data network. What matters is consistency. As one manufacturer puts it, it doesn’t matter which standard you choose, but it matters enormously that you use the same one consistently.

T568B is the more common choice in U.S. commercial installations, and one connector manufacturer describes it as the overwhelming standard in commercial deployments. If a building already uses one scheme, match it.

Solid vs. Stranded Cable

Ethernet cable comes in two conductor types, and each has a specific job.

• Solid copper is used for the permanent runs inside walls and ceilings. Permanent wiring used in structured cabling is solid.
• Stranded copper is used for patch cords. It is more flexible and withstands more bending without breaking.

Stranded cable has slightly higher resistance and more attenuation per unit length than solid, which is acceptable for the short patch cord lengths (1–5 meters) where it is used. That is one reason the standard caps patch cords at a small share of the 100-meter channel.

Straight-Through vs. Crossover Cables

Nearly every Ethernet cable in use today is a straight-through cable, with the same wiring scheme on both ends. Crossover cables, which swap pairs so two similar devices can connect directly, are mostly a thing of the past. Understanding what 3-core cables are used for can provide additional context when comparing cable designs and their intended applications.

That change came from a feature called Auto MDI-X. Introduced in 1998, this made the distinction between uplink and normal ports and manual selector switches on older hubs and switches obsolete. Today, most modern Ethernet equipment supports automatic medium-dependent interface crossover, commonly called auto MDI-X. Consequently, purpose-built crossover cables are far less common today.

Multigigabit Ethernet and Wi-Fi

Faster Wi-Fi changed what businesses expect from their cabling. Modern access points can exceed 1 Gbps, which created a bottleneck on older gigabit links.

The industry answered with IEEE 802.3bz, known as multigigabit or NBASE-T. The new IEEE 802.3bz standard adopted much of the baseline technology of the NBASE-T specification and was approved in September 2016. It allows 2.5GBASE-T and 5GBASE-T to be deployed at a cable length of up to 100 m on Cat 5e or better cables.

That means many existing Cat5e and Cat6 runs can deliver more speed with only a switch upgrade. But there are limits. Newer access points draw more power, and traditional Cat 5e and Cat 6 cables generate more heat than Cat 6A. When used in large bundles, the cable’s temperature could increase enough to significantly impact performance.

For new work, the TIA guidance points to Cat6A. TIA TSB-162-B, Telecommunications Cabling Guidelines for Wireless Access Points, recommends installing Cat 6A for horizontal cabling to WAPs. TSB-162-B also recommends using a grid-based zone cabling architecture, with at least two Cat 6A cable runs to each WAP in the grid.

Key point: Existing Cat5e or Cat6 may support multigig speeds today. New cabling for Wi-Fi 6E and Wi-Fi 7 access points should generally be Cat6A.

Where Fiber and Coax Fit

Twisted pair is the most common network cable, but it is not the only one in a commercial building.

Fiber optic cable handles the long, high-bandwidth links between telecom rooms, floors, and buildings. Market research consistently shows fiber growing fastest in backbones and data centers.

Coaxial cable is still used for cable TV, carrier broadband service entry, and some legacy analog cameras. It is rarely used for internal business networks today.

A typical modern building combines them: fiber for the backbone, twisted pair to every device, and coax only where a carrier or TV system requires it.

How to Choose the Right Network Cable for Your Building

Use these steps to decide which cable belongs in your project.

1. List every connected device. Count workstations, phones, printers, Wi-Fi access points, cameras, door readers, displays, and POS terminals.
2. Identify power needs. Note which devices use PoE and how much power they draw. High-power devices favor Cat6A and smaller bundles.
3. Measure run lengths. Keep horizontal runs within 90 meters. Longer distances between rooms or buildings call for fiber.
4. Set speed targets. Gigabit desks are well served by Cat6. Multigig access points and 10-gigabit links point to Cat6A.
5. Check the environment. Heavy electrical noise may call for shielded cable. Air-handling spaces require plenum-rated jackets.
6. Plan for the life of the cable. Cabling usually outlasts several generations of switches and access points. Spending a bit more on Cat6A for new construction often costs less than recabling later.
7. Insist on certification testing. Ask for saved test reports on every run so you know the cable performs as rated.

If you are planning a project in Carson, Long Beach, or the greater Los Angeles area, our [Network Cabling Company Carson CA](INTERNAL LINK) and [Commercial Network Cabling Company in Carson, CA](INTERNAL LINK) pages explain how we scope and install these systems.

Common Mistakes and Misconceptions

Buying cheap copper-clad aluminum (CCA) cable. CCA looks like copper but uses an aluminum core. The Category 5 specification requires conductors to be pure copper. There has been a rise in counterfeit cables, especially of the copper-clad aluminum (CCA) variety. According to Fluke Networks, cables made with CCA conductors do not have a valid safety listing per the National Electrical Code (NEC), and can’t be legally installed into areas of buildings that require CM, CMG, CMX, CMR or CMP rated cables. For PoE devices, the problem gets worse. Its higher resistance compared to equivalent-gauge pure copper results in more voltage drop and more heat under PoE load.

Mixing T568A and T568B in one system. Both work, but mixing them on opposite ends of a cable creates an accidental crossover and makes troubleshooting harder.

Assuming Cat7 or Cat8 is better for an office. Neither is designed for typical office horizontal cabling. Cat6 or Cat6A with RJ45 connectivity is the right fit.

Using stranded cable for permanent runs. Stranded cable belongs in patch cords. Solid copper belongs in walls and ceilings.

Trusting the jacket print alone. Category markings on a box or jacket do not guarantee performance. Buy from reputable manufacturers and certify every installed link.

Assuming all old cable must be replaced. Thanks to 802.3bz, existing Cat5e and Cat6 can often support 2.5 or 5 Gbps. A site assessment can show whether a switch upgrade is enough.

Future Trends for Network Cabling

A few trends will shape which cable is “most common” over the next several years:

• Cat6A becoming the new baseline. As Wi-Fi 7 and higher-power PoE spread, more new commercial projects are specifying Cat6A from the start.
• More fiber in backbones. Data center growth and higher uplink speeds keep pushing fiber deeper into buildings.
• Multigig at the edge. 2.5 and 5 Gbps switch ports extend the life of existing Cat5e and Cat6.
• More devices on PoE. Lighting, sensors, and building systems are increasingly powered over Ethernet, which puts more focus on cable quality, bundle size, and heat.

Even with those shifts, twisted pair copper is likely to remain the most common cable at the device level, because nothing else combines low cost, RJ45 compatibility, and power delivery.

Key Takeaways

• The most common type of network cable is four-pair unshielded twisted pair Ethernet with RJ45 connectors.
• Cat6 leads current installations, Cat5e has the largest legacy footprint, and Cat6A is growing fastest in new commercial work.
• Fiber may lead some market reports by revenue, but copper still connects most devices.
• T568A and T568B perform the same; consistency is what matters.
• Crossover cables are largely obsolete thanks to Auto MDI-X.
• Avoid copper-clad aluminum cable, especially for PoE.
• For new Wi-Fi 6E and Wi-Fi 7 access points, TIA guidance recommends Cat6A.

Frequently Asked Questions

What is the most common type of network cable?
The most common network cable is unshielded twisted pair (UTP) Ethernet cable with RJ45 connectors. Cat6 is the most widely installed category in new business networks today.

What is the most common Ethernet cable category?
Cat6 leads current installations. Cat5e is still very common in older buildings, and Cat6A is increasingly chosen for new commercial projects that need 10-gigabit speeds or high-power PoE.

Is Cat5e still good enough?
Cat5e supports gigabit Ethernet to 100 meters and can carry 2.5 Gbps with multigigabit switches. For new installations, Cat6 or Cat6A is the better long-term choice.

Should I use Cat6 or Cat6A?
Cat6 works well for standard office connections. Cat6A is recommended for Wi-Fi access points, 10-gigabit links, high-power PoE devices, and new construction meant to last many years.

What is the difference between RJ45 and 8P8C?
They refer to the same connector in everyday networking. 8P8C is the technical name for the eight-position, eight-contact modular connector, while RJ45 is the common industry term.

Do I need a crossover cable?
Usually not. Most modern network equipment supports Auto MDI-X, which adjusts automatically so standard straight-through cables work between any two devices.

Is fiber replacing Ethernet cable?
Fiber is replacing copper in backbones and data centers, but twisted pair remains the standard for connecting devices because it is less expensive and can deliver Power over Ethernet.

How can I tell if a cable is copper-clad aluminum?
CCA often looks identical to pure copper. Check the manufacturer’s specifications, buy from reputable suppliers, avoid unusually cheap bulk cable, and have installed runs certified.