Cabling Infrastructure Design
Understand horizontal runs, backbone cabling, telecom rooms, consolidation points, MUTOAs, and work areas.
- State the maximum horizontal cabling distances for permanent link and channel
- Describe the role of telecom rooms and entrance facilities
- Explain the function of consolidation points and MUTOAs
- Identify work area design requirements and outlet placement options
Leçon 1
Horizontal & Backbone Cabling Models
The Two Cabling Subsystems
Structured cabling divides into two primary subsystems: horizontal cabling (connecting the telecom room to work area outlets on the same floor) and backbone cabling (connecting telecom rooms, equipment rooms, and entrance facilities between floors and buildings).
Horizontal Cabling Distance Rules
The most frequently tested distance rules in data cabling are the horizontal limits:
The permanent link is the fixed cabling from the patch panel in the telecom room to the outlet at the work area - a maximum of 90 meters. The channel includes the permanent link plus patch cords at both ends (in the TR and at the work area) - a maximum of 100 meters total.
Exam Tip
The exam tests both numbers. 90 m permanent link, 100 m channel - this is the single most important distance rule in structured cabling. The 10 m difference accounts for patch cords at both ends.
Backbone Cabling
Backbone cabling connects telecom rooms (TRs) and equipment rooms (ERs) between floors and buildings. It carries aggregated traffic from multiple horizontal connections.
Backbone links typically use:
- Multimode fiber for intra-building connections (up to 300 m for OM3/OM4)
- Singlemode fiber for inter-building connections (up to 3,000 m+)
- Copper backbone for shorter runs (limited to 90 m per TIA-568)
Horizontal Cabling
Direction: TR to work area (same floor)
Media: Typically Cat 6/6A copper
Max distance: 90 m permanent / 100 m channel
Topology: Star from TR
Backbone Cabling
Direction: Between TRs, ERs, EFs (between floors/buildings)
Media: Typically fiber optic
Max distance: Varies by fiber type and application
Topology: Star or hierarchical star
Horizontal cabling maximum is 90 m permanent link and 100 m channel. Backbone cabling connects TRs and ERs between floors and buildings, typically using fiber optic media.