Appendix C: Cables

EIA/TIA 568B RJ-45 Wiring Standard, 10/100BASE-TX Straight-through Cable

End A

1

1

End B

2

2

 

3

3

 

 

4

4

 

 

5

5

 

 

6

6

 

 

7

7

 

 

8

8

 

Figure C-2. Straight-through Wiring

C.4 Crossover Wiring

If the twisted-pair cable is to join two ports, and 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 autonegotiation is enabled for any RJ-45 port on this switch, you can use either straight-through or crossover cable to connect to any device type.)

You must connect all four wire pairs as shown in Figure C-3 to support Gigabit Ethernet.

EIA/TIA 568B RJ-45 Wiring Standard, 10/100BASE-TX Crossover Cable

 

1

1

End B

End A

2

2

 

3

3

 

 

4

 

 

4

 

 

5

5

 

 

6

6

 

 

7

7

 

8

8

 

Figure C-3. Crossover wiring.

C.5 1000BASE-T Pin Assignments

All 1000BASE-T ports support automatic MDI/MDI-X operation, so you can use straight-through cables for all network connections to PCs or servers, or to other switches or hubs.

Table C-2 shows the 1000BASE-T MDI and MDI-X port pinouts. These ports require that all four pairs of wires be connected.

NOTE: For 1000BASE-T operation, all four pairs of wires are used for both transmit and receive.

Use 100-ohm Category 5, 5e, or 6 unshielded twisted-pair (UTP) or shielded twisted-pair (STP) cable for 1000BASE-T connections. Also be sure that the length of any twisted-pair connection does not exceed 328 feet (100 m).

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LGB5028A User‘s Manual

 

 

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Black Box 24 + or 48 + 4-Port Gigabit Managed Switch with SFP+ 10G, LGB5052A Crossover Wiring, 1000BASE-T Pin Assignments