What Is Cat 4 Cable Used For? A Complete Guide to This Legacy Networking Standard

If you’ve ever researched network cables like Cat5e, Cat6, or Cat7, you might have come across something called Cat 4 cable. While it’s rarely used in modern networking, understanding what Cat 4 cable is and how it was once used helps you see how far data cabling technology has evolved.

Let’s break down what Cat 4 Ethernet cable is, what it was used for, and why it’s no longer common in today’s installations.

What Is Cat 4 Cable?

Cat 4, short for Category 4 cable, is a type of twisted pair network cabling that was widely used in the early days of computer networking. It’s part of the same family as Cat3, Cat5, and newer versions like Cat6 and Cat7.

Cat 4 cables typically support data transfer speeds of up to 16 Mbps (megabits per second) and a maximum distance of 100 meters (328 feet). They use four twisted pairs of copper wire, which help reduce electrical interference and signal loss.

When it was first introduced, Cat 4 was considered an improvement over Cat3, offering faster speeds and better performance for growing business networks in the 1990s.

What Was Cat 4 Cable Used For?

Cat 4 cables were mainly used in Token Ring networks and 10Base-T Ethernet systems, both common before today’s high-speed LANs became standard.

Here are some of its main uses:

Office networks – Used to connect computers, printers, and servers in small to mid-sized businesses.
Telephone systems – Supported analog and early digital voice transmission.
Token Ring networks – One of the primary systems Cat 4 was designed for, especially in IBM networking setups.
Early Ethernet connections – Served as a bridge between slower Cat3 systems and the more advanced Cat5 standard.

While it worked well for early networking applications, it quickly became outdated as demand for higher bandwidth grew.

Why Cat 4 Cable Is Obsolete Today

As technology advanced, Cat 5 and later Cat 5e and Cat 6 cables replaced Cat 4 due to their higher performance and compatibility with faster Ethernet standards.

Here’s why Cat 4 is no longer in use:

Limited speed – 16 Mbps is far below modern requirements (today’s standard Cat6 supports up to 10 Gbps).
Incompatibility – Not suitable for modern Ethernet networks like 100Base-TX or Gigabit Ethernet.
No certification – Cat 4 was never officially standardized under current ANSI/TIA cabling standards.
Lack of availability – Most manufacturers have stopped producing Cat 4 cable.

If you still find Cat 4 in older buildings, it’s typically part of a legacy system that hasn’t been upgraded yet. Replacing it with Cat6 or Cat6a is highly recommended to ensure better performance and future-proofing.

Modern Alternatives to Cat 4 Cable

If you’re updating an old network or installing new cabling, here are the recommended modern replacements:

Cat 5e – Supports up to 1 Gbps speeds and is common in residential networks.
Cat 6 – Handles up to 10 Gbps over short distances and is ideal for most businesses.
Cat 6a – Provides even better performance with improved shielding against interference.
Fiber optic cable – Best for high-speed backbones or long-distance data transmission.

These options provide higher bandwidth, better performance, and compliance with current structured cabling standards.

Should You Replace Cat 4 Cable?

Yes — if your building or office still has Cat 4 cabling, it’s time to upgrade. Outdated cables can limit your network speed, reduce reliability, and prevent you from using modern technologies that require higher bandwidth.

Professional installers can help design and implement a structured cabling system that meets current performance and safety standards.

Key Takeaways

Cat 4 cable was used mainly in Token Ring and early Ethernet networks.
It supports speeds up to 16 Mbps, which is far below modern standards.
It’s considered obsolete and has been replaced by Cat 5e, Cat 6, and newer types.
Upgrading ensures faster speeds, stronger signals, and better compatibility with modern systems.

If you’re unsure what type of cabling your property uses, a professional inspection can help determine whether you need an upgrade.