CHAPTER 5 Cabling the Device
Mediant 800 Gateway & E-SBC | Hardware Installation Manual
Figure 5-14: Cabling E1/T1 Ports
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 that are received
from the Tel side (e.g., PBX) directly to the PSTN (instead of to the IP network).
Support for PSTN fallback:
■
Mediant 800B:
PSTN Fallback is supported only when using a module with dual E1/T1 ports.
In the event of a PSTN fallback, the module's metallic relay switch automatically connects
Port #1 with Port #2 to route calls between the Tel and PSTN side.
■
Mediant 800C:
In the event of a PSTN fallback, the module's metallic relay switch
automatically connects Port #1 with Port #2 (and Port #3 with Port #4 for the four E1/T1 port
module) to route calls between the Tel and PSTN side. These ports must be on the same
module.
●
PRI port cabling must be routed only indoors and must not exit the building.
●
To protect against electrical shock and fire, use a 26 AWG min. wire to connect the
PRI ports to the PSTN.
●
To comply with EMC rules and regulations, use shielded twisted pair (STP) cables
for E1 interfaces.
Cable specifications:
■
Cable: STP cable of 26 AWG min.
■
Connector Type: RJ-48c
■
Connector Pinouts:
Figure 5-15: RJ-48c Connector Pinouts for E1/T1 PSTN Fallback
➢
To connect the PRI ports for PSTN Fallback:
1.
Connect one of the PRI ports to the PBX.
2.
Connect the second PRI port to the PSTN.
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