Media5 Mediatrix C710, Hardware Installation Manual

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RJ-45 Cable Hardware Installation Guide
Mediatrix C7 Series – Digital Gateway 31
Crossover Cable
A RJ-45 crossover cable is used when only two systems are to be connected to each other, peer to peer, at
the Ethernet Cards by “crossing over” (reversing) their respective pin contacts. An example would be
connecting two computers together to create a network. The crossover eliminates the need for a hub when
connecting two computers. A crossover cable may also be required when connecting a hub to a hub, or a
transceiver to transceiver or repeater to repeater. When connecting a hub to a transceiver, a straight through
cable is always used.
A crossover cable is sometimes called a null modem. The coloured wires at either end are put into different
pin numbers, or crossed over.
Figure 8: Crossover Connectivity
Note:
This is not an IEEE supported configuration and should be used for test purposes only.
1- TX+
2- TX-
3- RC+
6- RC-
TX+ -1
TX- -2
RC+ -3
RC- -6