Networking:The SoftCo connects to the carrier's network through the PRA trunk.
Description:The SoftCo5816 has run properly for a year. After a thunder day, the SoftCo user cannot make an outgoing call and the RFA indicators of all trunks blink. Other devices in the office run properly.
Step 1 Check the DTU board by replacing it with a new one. If the RFA indicators still blink, the DTU board is not damaged.
Step 2 Check the transmission line. If RFA indicators are off during the loopback test about receiving and sending status of the local end, the transmission at the local end is normal.
Step 3 Perform the loopback test about receiving and sending status of the E1 trunk from the carrier side. If the peer RFA indicators are off, the transmission at the peer end is normal.
Step 4 Connect the faulty SoftCo5861 to the SoftCo9500. If the E1 trunk status is normal, users can call each other after data configuration.
Step 5 Connect the carrier E1 trunk to the SoftCo9500. If the E1 trunk status is normal, users can call each other after data configuration.
Step 6 If the fault persists, connect the standby SoftCo9500 to the carrier devices to restore services.
Step 7 After restoring services, move SoftCo9500 onto the cabinet, and RFA indicators blink. Lift SoftCo9500 from the cabinet, and the indicators work properly.
Step 8 Check for the cabinet ground fault and rectify the ground bars to eliminate the fault.
The possible causes are as follows:
The DTU board is damaged.
The transmission line is faulty.
The Device is no effective grounding.
It is hard to locate the ground problem at the beginning because the devices have run properly for a year and the equipment room grounding is normal. Various tests have proved that the devices and transmission have no problem. This causes deadlock of fault location. Pay attention to the following points when processing a trunk connection problem:
Lightning strikes may damage the grounding system.
Poor ground may cause abnormal E1 trunk status. For example, RFA indicators blink.