PSTN Phone Line Troubleshooting - Quality and Noise Issues

The most common cause of issues on PSTN lines is local cabling, either coming from the socket or within the building.
Note on Scope of Liability for PSTN Faults
Please note that internal wiring within the building is the customers responsibility.  Telstra's responsibility for the lines starts at the street level only.
For this reason, it is critical that internal wiring be checked and tested before a fault is escalated for Exchange and street-level investigation.  In the event that a fault is escalated and the cause is found to be within the customers premises (including wiring within the building) the technician may be unable to resolve the problem and a call out charge will apply.
Troubleshooting steps:
  1. Confirm that a dial tone is present and an outbound call can be made.  If calls cannot be made, please see the appropriate knowledge base article for this issue.
  2. Perform an isolation test by disconnecting all other devices, such as extra phones, faxes, extension cords, modems, security systems and cabling, double adaptors and Foxtel Digital units on the phone line.
  3. If there is a back to base burglar alarm there is a requirement that this be isolated by a central filter to be placed before the back to base alarm which must be on the end user side of the filter.
  4. Confirm there are no issues with the local equipment such as the phone or modem in use
  5. Confirm the end user premises wiring is cabled to specification (including inline and central filters)
  6. Ensure extension cables and third party double adapters are removed and the phone or modem is plugged in directly (without a filter) into the first socket
  7. Ensure that the end user is using a phone or modem approved by Telstra for interfacing with the Telstra phone or  DSL network (“Approved Device”).
  8. Disconnect the phone or modem for a minimum of 30 seconds and test again



If the above troubleshooting steps have been performed and you are confident that the issue is outside of the premises, please send an e-mail to requesting escalation of the fault.  Please be sure to include the following details:

  • Confirmation of troubleshooting steps performed
  • The site address and faulting phone number
  • Business hours onsite contact and phone number



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