Connecting PSTN Fallback for E1/T1 Trunks

The device supports PSTN Fallback for E1/T1 lines. If the device loses power, for example, due to a power outage or the unplugging of its power cable, it automatically routes calls from the Tel side to the PSTN (instead of the IP network). This guarantees call continuity.

PSTN Fallback is supported on E1/T1 ("TRUNKS") modules that provide two or four spans. In the event of a PSTN fallback, the module's metallic relay switch automatically connects trunk Port 1 (I) to Port 2 (II), and / or trunk Port 3 (III) to Port 4 (IIII) of the same module. For example, if a PBX trunk is connected to Port 1 and the PSTN network is connected to Port 2, when PSTN Fallback is activated, calls from the PBX are routed directly to the PSTN through Port 2.

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To connect digital trunk interfaces for 1+1 PSTN Fallback:

1.

Connect Trunk 1 to a PBX.

2.

On the same TRUNKS module, connect Trunk 2 to the PSTN.

Cabling (Ports 1 and 2) PSTN Fallback