Step 1 Log in to the SoftCo and run the show subscriber command to verify that a number is assigned for the user in the corresponding POTS port.
Step 2 Run the show board command to check whether the MRU exists.
If no MRU exists, run the config add board slot <2-9> type mru command to add one.
If the MRU exists, check whether the MRU is in the OK state.
If the MRU is not in the OK state, check whether the MRU is inserted in the slot properly.
1. If no, insert the MRU properly.
2. If yes, change another MRU.
Step 3 If the fault persists, contact Huawei technical support engineers.