What type of fiber optic cable is typically used in computer rooms

In computer rooms and data centers, multimode fiber (OM3 or OM4) with duplex configuration and LSZH or plenum-rated jackets is most commonly used for high-speed, short-distance networking.

Fiber Type

Multimode fiber (MMF) is the standard choice for indoor computer rooms because it supports high-speed data transmission over short distances, typically within a building or data center. Common grades include OM3 and OM4, which support 10Gbps to 100Gbps networks, with OM4 offering longer reach and better performance for larger setups. Single-mode fiber (SMF) is used less frequently indoors but is preferred for long-distance or backbone connections due to its small core and high bandwidth capabilities .

Fiber Count and Configuration

Fiber cables in computer rooms are usually duplex, containing two strands—one for transmitting and one for receiving—enabling full-duplex communication. Simplex cables with a single strand are used in specialized cases, such as bidirectional transceivers, but duplex is standard for most networking applications .

Cable Jacket Types

Indoor fiber cables are designed with safety and installation in mind. Common jacket types include:

• LSZH (Low Smoke Zero Halogen): Produces minimal smoke and no toxic gases in case of fire, ideal for data centers and office buildings.
• Plenum-rated: Suitable for air-handling spaces like ceilings or ducts, offering high fire resistance and low smoke emission.
• PVC: Flexible and cost-effective for general indoor use, though less fire-resistant than LSZH or plenum .

Connector Types

Fiber cables are terminated with standard connectors such as LC, SC, or MPO/MTP. LC connectors are widely used for high-density patch panels, while MPO/MTP connectors are common in high-speed, high-density data center environments. Connector polish types (PC, UPC, APC) affect signal quality and return loss, with APC providing the highest performance for sensitive applications .

Specialized Indoor Cables

For high-density or high-speed setups, breakout cables and ribbon fiber cables are used. Breakout cables allow individual fibers to be terminated separately, while ribbon cables support mass fusion splicing and high-density connections, making them ideal for modern data centers with 40G, 100G, or higher network speeds .

Summary

In computer rooms, the typical fiber optic setup includes duplex multimode fiber (OM3/OM4) with LSZH or plenum-rated jackets, terminated with LC or MPO/MTP connectors. This configuration balances high-speed performance, safety, and ease of installation, making it suitable for LANs, server connections, and data center backbones .