Structured cabling (UTP Cat 5): within a 100 m channel, what is the typical maximum length recommended for a work-area patch cable from the wall outlet to the PC?

Introduction / Context:
TIA/EIA-568 structured cabling guidelines define a 100 m maximum channel length for copper twisted-pair Ethernet (typically 90 m permanent link plus up to 10 m of patch cords). Within that budget, a common design practice is to allocate a short work-area patch from the outlet to the device, ensuring margin for the telecom room patch cords as well.

Given Data / Assumptions:

• Category: UTP Cat 5 (applies similarly to Cat 5e/6 concepts).
• Total Ethernet channel length target: 100 m.
• Permanent link: approximately 90 m from patch panel to outlet.
• Work-area patch cable: short length to the PC at the desk.

Concept / Approach:
A widely used rule-of-thumb assigns roughly 5 m total for patching (for example, 2 m in the telecom room and up to 3 m in the work area). Keeping the work-area patch around 3 m maintains compliance and preserves flexibility for moves/adds/changes without exceeding the 100 m channel maximum.

Step-by-Step Solution:

Verification / Alternative check:
Many enterprise cabling standards and vendor design guides present examples with 90 m permanent links and 3 m end-user cords to maintain channel performance.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing permanent link limits with patch cord allowances, or forgetting both ends’ patching must fit within the 10 m budget.

Final Answer:
3 meters.