Installation Guide for the Model FE104 and Model FE108 Fast Ethernet Hubs
Fast Ethernet and Cabling Guidelines
C-3
Cable Lengths
Category 5 distributed cable that meets ANSI/EIA/TIA-568-A building wiring standards can be a
maximum of 328 feet (100 m) in length, divided as follows:
•
20 feet (6 m) between the hub and the patch panel (if used)
•
295 feet (90 m) from the wiring closet to the wall outlet
•
10 feet (3 m) from the wall outlet to the desktop device
The patch panel and other connecting hardware must meet the requirements for 100 Mbps
operation (Category 5). Workmanship quality is a must. Only 0.5 inch (1.5 cm) of untwist in the
wire pair is allowed at any termination point.
Cable Specifications
Table C-1 lists the electrical requirements of the Category 5 cable.
Table C-1.
Electrical requirements of Category 5 cable
Specification
Requirements
Number of pairs
Two or Four
Impedance
100
Ω
±
15%
Mutual capacitance at 1 KHz
5.6 nF per 100 m
Maximum attenuation
(dB per 100 m, at 20
°
C)
at 16 MHz: 8.2
at 31 MHz: 11.7
at 100 MHz: 22
NEXT loss (dB minimum)
at 16 MHz: 44
at 31 MHz: 39
at 100 MHz: 32
