English

Structured Cabling: Backbone Cabling vs Horizontal Cabling

Updated on Dec 22, 2021 by
72.1k

Structured cabling is the backbone of modern business infrastructure, enabling seamless communication and data transfer. It is a standardized architecture that provides a comprehensive telecommunications infrastructure, consisting of backbone cabling and horizontal cabling. In this article, we will explore the differences between backbone cabling and horizontal cabling, and how to choose the right cabling solution for your business.

Structured Cabling System Basics

To understand backbone cabling and horizontal cabling, let’s understand the five subsystems of structured cabling first. These five subsystems are often found throughout a building and are connected so that various types of data can be transmitted consistently and securely (shown in the figure below).

Structured Cabling
  • Equipment Room: A room with equipment that serves the users inside the building.

  • Telecommunications Room: This room contains the telecommunications equipment that connects the backbone and horizontal cabling subsystems.

  • Backbone Cabling: A system of cabling that connects the equipment rooms and telecommunications rooms.

  • Horizontal Cabling: The system of cabling that connects telecommunications rooms to individual outlets or work areas on the floor.

  • Work Area Components: These connect end-user equipment to outlets of the horizontal cabling system.

Backbone Cabling

Backbone cabling, also known as vertical cabling, is the inter-building and intra-building cable connections in a structured cabling system. It typically connects telecommunications rooms, equipment rooms, and entrance facilities. Backbone cabling provides the main route for data between different buildings, floors, and equipment rooms within a building. It carries the bulk of the data between the main distribution frame (MDF) and intermediate distribution frames (IDFs).

The components of backbone cabling include high-capacity cables, such as fiber optic or high-pair-count copper cable, and connecting hardware like patch panels, connectors, and cable management systems.

Backbone Cabling

Fiber optic cables are the optimal selection for backbone cabling due to their superior bandwidth capabilities compared to conventional Cat5, Cat6, or even Cat7 twisted pair copper cables. Additionally, fibers can cover significantly longer distances than copper cables, making them particularly appealing for backbone cabling structures.

Horizontal Cabling

Horizontal cabling is the cabling that connects telecommunications rooms (TRs) to individual work area outlets or devices (e.g., computers, phones) within a building or on a floor. Horizontal cabling provides the connection between the telecommunications room and the end-user devices (as shown below). It is the final link in the structured cabling system and is responsible for delivering data, voice, and video services to the user's work area.

The components of horizontal cabling typically consist of twisted-pair copper cable (e.g., Cat5e, Cat6, Cat6a) or fiber optic cables, patch panels, wall outlets, and patch cords.

Horizontal Cabling

Both Ethernet and fiber optic cables are suitable for horizontal cabling. For voice applications, a four-pair 100-ohm unshielded twisted-pair (UTP) cable, such as Cat5e cable, Cat6 cable, or Cat6a cable, is typically recommended. For data transmission, fiber optic cables, such as two-fiber 62.5/125-micron or 50/125-micron multimode cables, or those with a higher fiber count, are commonly used.

To adhere to EIA/TIA wiring standards, individual cables should not exceed 90 meters in length between the work area outlet and the telecommunications room's patch panels. Patch cords used to connect the patch panel to hubs and switches in the telecommunications room should not exceed a total distance of 6 meters. Cables connecting users' computers to outlets should be limited to 3 meters in length.

Backbone Cabling vs Horizontal Cabling

Backbone cabling serves as the primary pathway for data transmission between buildings, floors, and equipment rooms, while horizontal cabling connects telecommunications rooms to individual work area outlets. The key differences between backbone cabling and horizontal cabling lie in their purposes, locations, cable types, and distance limitations.

Structured Cabling Backbone Cabling Horizontal Cabling
Purpose It carries the bulk of data traffic between the main distribution frame (MDF) and intermediate distribution frames (IDFs). It is the final link in the structured cabling system and delivers data, voice, and video services to the user's work area.
Location Typically run vertically, connecting different floors or buildings within a campus or complex. Run horizontally, connecting TRs to work area outlets within a building or on a floor.
Cable Types High-capacity cables, such as fiber optic or high-pair-count copper cables. Twisted-pair copper cables (e.g., Cat5e cable, Cat6 cable, Cat6a cable) or fiber optic cables.
Distance Limitations Span longer distances than horizontal cabling. Limited to 90 meters (295 feet) from the TRs to the work area outlet.

Conclusion

Backbone cabling and horizontal cabling are both essential components of a structured cabling system, each serving distinct purposes within a network infrastructure. Both have their advantages and considerations, and the right choice depends on the specific requirements of the network and the building or campus layout. By understanding the differences between backbone and horizontal cabling, businesses can make informed decisions to ensure reliable and efficient communication and data transfer within their infrastructure.

You might be interested in

Knowledge
See profile for Margaret.
Margaret
Data Center Cabling Guide
May 19, 2023
30.9k
Knowledge
Knowledge
Knowledge
See profile for Sheldon.
Sheldon
Decoding OLT, ONU, ONT, and ODN in PON Network
Mar 14, 2023
381.5k
Knowledge
See profile for Irving.
Irving
What's the Difference? Hub vs Switch vs Router
Dec 17, 2021
365.6k
Knowledge
See profile for Sheldon.
Sheldon
What Is SFP Port of Gigabit Switch?
Jan 6, 2023
331.2k
Knowledge
See profile for Migelle.
Migelle
PoE vs PoE+ vs PoE++ Switch: How to Choose?
Mar 16, 2023
417.8k
Knowledge
Knowledge
Knowledge