-
Check if you are using straight or crossover cable (you should use the straight one).
-
Check if jumpers on the PRI board are set correctly for the NT/TE mode (JP2 and JP3, see the picture below, you can also find more details in the manual).
-
Check the Master/Slave settings in the ISDN parameters menu.
-
Check settings of CRC of Layer 1 on PRI interface (see the section Gateway configuration>ISDN parameters: CRC in the PRI config tool).
