This topic describes how to troubleshoot a call fails that occurs on the SS7 trunk.
Symptom
The following faults often occur on the SS7 trunk:
- A busy tone is heard when an incomplete called number is dialed.
- A busy tone is heard when a complete called number is dialed.
Possible Causes
The possible causes are as follows:
- The clock source is not configured.
- The intra-office and outgoing prefixes are not configured.
- The board status is abnormal.
- The trunk circuit is faulty.
- The trunk link status is faulty.
Procedure
- See E1/T1 Trunk Exception to check the clock source is configured.
- See Step 3 and Step 4 in Call Fails on the PRA Trunk to check whether the intra-office and outgoing prefixes are configured and whether the board status is normal.
- See Logging In to the unified gateway Using the LMT to run the show tkc by office no officeno command check trunk circuit status (the value of State field).
- If the status is ISOLATET, run the config cancelisolate board slot slotcommand to cancel board isolation.
- If the status is FAULT, see Configuring Signaling Data to check whether the trunk data is correct.
- If the status is IDLE, go to the next step.
- Run the show mtplink command to check the trunk link status (the value of State field).
- If the status is FAULT, seeConfiguring Signaling Data to check whether the trunk data is correct.
- If the status is OK, go to the next step.
- If the fault still persists, collect detailed fault information and related logs by referring to Collecting and Reporting Fault Information and send them to the service provider.
