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Jack PC Hardware User Manual - Training Department
Version 0506
6 WIRING CONFIGURATIONS
6.1 LAN wiring basics
Some facts about the LAN cabling:
• The wires inside LAN cables are made of 4 x twisted pairs marked with similar color
(i.e. Orange and White-Orange).
• For the 10/100 LAN function to work – only 4 wires (2 pairs) are needed as minimum:
two RX lines and two TX lines (1 and 2, 3 and 5).
• Giga LAN uses all 8 wires in the cable + the shielding.
• 4 unused wires (4,6,7,8) are optional and typically unused in 100 Base-T networks
although sometimes these 4 wires are used for analog telephony.
• Shield may be needed (connected) to reduce noise and enable full cable length (100
meters). In CAT 5 and higher the shielding is mandatory.
• Power from PoE enabled switch can pass thorough the same same minimal RX and
TX lines although it is preferred to have all 8 wires wired.
• Power from Midspan power injector can not pass thorugh the minimal 4 wires as it is
using the additional unused 4 to deliver power to the powered device.
• Cable should be straight (pin to pin) altough it may also work in crossed configuration
as the Jack-PC supports MDIIIX functionality.
• LAN cabling is typicaly limited in range to 100 meter (328 feet).
Figure 6.1 - Non-shielded LAN cable
