CABLES
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 CPE, you can use either straight-through or crossover cable to connect to any device type.)
EIA/TIA 568B RJ-45 Wiring Standard
10/100BASE-TX Crossover Cable
| | White/Orange Stripe | | |
| | Orange | | |
| 1 | White/Green Stripe | 1 | |
End A | 2 | Blue | 2 | End B |
| 3 | 3 | |
| | |
| 4 | White/Blue Stripe | 4 | |
| 5 | 5 | |
| | |
| 6 | Green | 6 | |
| 7 | 7 | |
| | |
| 8 | White/Brown Stripe | 8 | |
| | | |
| | Brown | | |
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.