Will Fiber Optic Cables Replace Copper Ethernet Cables?

As cloud computing, big data, 5G, and other new technologies emerge, data centres continue to expand in scale, making their architecture and cabling increasingly complex. The lightweight and reduced cost of fibre optics has made it increasingly popular for backbone networks, with fibre optics accounting for over 70% of the cabling in large data centres, far exceeding copper. Many copper cable practitioners worry that copper cables will be completely replaced by fibre optics.

network cable
network cable

However, recent research into the latest international standards ISO11801-1:2017 and ANSI/TIA-568.2-D suggests that Cat. 8 40G can fill the gap for copper twisted pair cables in 40G transmission applications.

Advantages of Fiber Optics over Copper Ethernet Cables

Fibre optics has higher transmission rates and bandwidth, making it ideal for high-bandwidth applications such as backbone networks.

Advantages of Copper Ethernet Cables over Fiber Optics

Copper cables use electrical pulses to transmit data and support voice signals. This makes them suitable for voice transmission, unlike fibre optics.

Copper cables can also conduct electricity while transmitting data, making them suitable for wireless access, POE power supply systems, and LED-based electrical systems.

Role of Copper Ethernet Cables in Data Centers

TIA standard TIA 568.2-D describes the essential applications of copper cables in data centres:

  • Cat8-rated 25GBase-T and 40GBase-T applications.
  • Coaxial balanced electrical cables (DACs) for 100GBase-CR2, 100GBase-CR4, and 200GBase-CR4 applications.
  • Main trunk fibre optic technology upgrades, including 200G/400G receivers and transceivers based on IEEE802.3bs and IEEE802.3cm, as well as the latest OM5 fibre technology.
  • The latest IEEE802.3bt POE standard for smart systems in data centre buildings.
  • Attenuation requirements for single-mode and multi-mode fibre in SAN networks.
  • Redundant connectivity models for different network scales and architectures (EOR, TOR).
  • Analysis of advantages and disadvantages of different network architectures (tree, spine-leaf, full-mesh).
  • Recommended network and cabling architectures for enterprise data centres, IDCs, micro-modules, and EDGE data centres.

Modular Plug Terminated Links (MPTLs)

The inclusion of MPTLs as an option for connecting devices in TIA-568.2-D is likely to drive the growth of RJ45 copper cable applications, especially in surveillance systems using IP cameras. The standard’s appendix also includes 28AWG network patch cables, which will improve airflow and space utilization in high-density applications.

Types of Copper Ethernet Cables

Copper cables come in various types, each with its application:

  • Cat5e Network Patch Cables: Bandwidth of 100MHz, maximum transmission rate of 1000Mb/s, suitable for home networks and indoor cabling
  • Cat6 Network Patch Cables: Bandwidth of 250MHz, maximum transmission rate of 10Gb/s, improved performance over Cat5e, typically limited to 55 meters
  • Cat6a Network Patch Cables: Bandwidth of 500MHz, the maximum transmission rate of 10Gb/s, supports distances up to 100 meters, thicker conductors make it suitable for industrial environments
  • Cat7 Network Patch Cables: Bandwidth of 600MHz, supports 10Gbps transmission rates at distances of 100 meters, strong shielding reduces attenuation, supports transmission rates of up to 40Gbps at 50 meters and 100Gbps at 15 meters
  • Cat8 Network Patch Cables: Bandwidth of 2000MHz, maximum transmission rate of 40Gb/s, limited to 30 meters, specifically designed for 25GBASE-T and 40GBASE-T applications


Copper cables continue to play a vital role in voice transmission, indoor networks, horizontal cabling, POE systems, and other applications. They will not be completely replaced by fiber optics. Copper technology is still under development, with Cat. 8 and Cat. 9 offering the potential to meet future connectivity demands.