T1 Crossover Cable, Loopback Plug

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Note: This is not included with the PBX.t1_crossover.png

The image displayed shows the cross-over cable pinout for a standard T1.  This cable should be plugged into your Smartjack (provided by the Carrier) and your PBXtra 's PRI card (Sangoma A10X model of cards).


Alternatively, Smartronix (example) sells T1/E1 or ISDN/PRI crossover adapters (same wiring, different colors - one is pale greenish-white or mint, the other is yellow).

If purchasing an adapter, make certain you get at least one crossover adapter.  Loopbacks are for testing.


A T1/PRI crossover cable is needed in certain situations where the transmit and receive pins are switched.  Not to be confused with an Ethernet crossover - the pinout is different.

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