Allied Telesis AT-MR820TR - Manual (Page 56)

Technical Specifications
34
Straight-through Wiring
If the twisted-pair link segment is to join two ports on a switch, and
only one of the ports has an internal crossover, the two pairs of wires
must be straight-through, as shown in Table 4.
Table 4: Straight-through RJ45 Pin Assignments
Crossover Wiring
Two AT-MR420TR/AT-MR820TR Micro Repeaters can communicate
only if the transmitter on one unit is connected to the receiver on the
other unit. This reversal, or crossover function, can be implemented
either in the wiring or in the device itself using the MDI/MDI-X switch.
When connecting AT-MR420TR/AT-MR820TR Micro Repeaters, a
crossover must be used in the wiring when using any port other than
4/8. See Table 5 for crossover pin assignments.
Table 5: Crossover RJ45 Pin Assignments
Hub Device
1 (TX+) 1 (TX+)
2 (TX-) 2 (TX-)
3 (RX+) 3 (RX+)
6 (RX-) 6 (RX-)
AT-MR420TR/MR820TR AT-MR420TR/MR820TR
1 (TX+) 3 (RX+)
2 (TX-) 6 (RX-)
3 (RX+) 1 (TX+)
6 (RX-) 2 (TX-)
MRx20TR(STP/UTP)_BookA Page 34 Thursday, April 3, 1997 5:24 PM