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Q38: What is the difference between different wiring configuration?
A38:Twisted Pair cabling uses an 8-wire modular connector called the
RJ-45. The trick is in making sure that you connect the right colored
wire to the right pin in the RJ-45. 568A, 568B, 258A and USOC are all
standards describing which wire goes on which pin.
No matter which cabling wiring configuration is adopted, the pairs are
always colored the same. Pair 1 is always blue.
Pair
Color
Wires
1 Blue
Blue & Blue with white stripes
2 Orange
Orange & Orange with white stripes
3 Green
Green & Green with white stripes
4 Brown
Brown & Brown with white stripes
The blue wire and the blue wire with white stripes ("blue/white"
for short) are twisted together within the cable, and this makes them
suitable for carrying.data The various standards define which pair is
attached to which pins on the RJ-45.
When recalling the wiring configurations, here are some basic rules:
* The solid color wires and the striped wires always alternate * * Pin
1 is always a striped wire.
* Pair 1, Blue, is always in the middle on pins 4 & 5.
568B (AKA 258A)
The TIA 568A standard is always the preferred way of terminating cable.
It matches the method of terminating cable that Northern Telecom used
for ISDN. 568B (AKA 258A) Before the TIA ever met to adopt the 568A standard
for cable terminations, AT&T had a very similar standard for terminating
their cable, called 258A.258A works just as well as 568A. In fact, the
TIA committee decided to include AT&T's 258A standard, but they called
it the 568B standard. 258A and 568B are exactly the same. This is what
happens when committees try to make everyone happy.Further, the TIA cabling
standard states one may use either 568A or 568B but not both in one cabling
system. As long as the wiring configuration is consistent. the system
will work fine.
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