User's Manual

115
Twisted-Pair Cable and Pin Assignments
B
Crossover Wiring
If the twisted-pair cable is to join two ports and either both ports are labeled with an
“X” (MDI-X) or neither port is labeled with an “X” (MDI), a crossover must be
implemented in the wiring. (When auto-negotiation is enabled for the RJ-45 port on
the Gateway, you can use either straight-through or crossover cable to connect to
any device type.)
Figure B-3 Crossover Wiring
Cable Testing for Existing Category 5 Cable
Installed Category 5 cabling must pass tests for Attenuation, Near-End Crosstalk
(NEXT), and Far-End Crosstalk (FEXT). This cable testing information is specified in
the ANSI/TIA/EIA-TSB-67 standard. Additionally, cables must also pass test
parameters for Return Loss and Equal-Level Far-End Crosstalk (ELFEXT). These
tests are specified in the ANSI/TIA/EIA-TSB-95 Bulletin, “The Additional
Transmission Performance Guidelines for 100 Ohm 4-Pair Category 5 Cabling.”
Note that when testing your cable installation, be sure to include all patch cables
between switches and end devices.
White/Orange Stripe
Orange
White/Green Stripe
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
EIA/TIA 568B RJ-45 Wiring Standard
10/100BASE-TX Crossover Cable
End A
End B
Green
Blue
White/Blue Stripe
Brown
White/Brown Stripe