Digium and Sangoma:
On TDM4xxP and TE1xxP cards, the LED's don't light up until the kernel module has been loaded. If you see it turned off even if the system is fully started please contact Skip2PBX technical support.

Digium TDM, Sangoma A2xx cards:
LED's will light up when FXO/FXS modules are plugged. They should be lighed up even if no cable is connected.

Digium TE cards, Sangoma A1xx cards:
By default, without a connected cable you should see a solid red light.

If you correctly configured your PBX, your Skip2PBX and you have plugged a cable you should see a solid green light.

If your LED is blinking between red and green light it means you have a configuration error (usually related to timing source).

PLEASE NOTE:
E1 and T1 ISDN/PRI cards need a special crossed cable:

PBX side	Signal	Description	Direction	Signal	Skip2PBX side
Shield	Ground	Shell/Braid		Ground	Shield
J1-1	RX Tip	Twisted Pair #1	<—	TX Tip	J2-4
J1-2	RX Ring	Twisted Pair #1	<—	TX Ring	J2-5
J1-3	RX Shield	Twisted Pair #3		TX Shield	J2-6
J1-4	TX Tip	Twisted Pair #2	—>	RX Tip	J2-1
J1-5	TX Ring	Twisted Pair #2	—>	RX Ring	J2-2
J1-6	TX Shield	Twisted Pair #4		RX Shield	J2-3