This guide is for troubleshooting some common issues with ISDN services.
Before trying to troubleshoot your equipment, we recommend checking our Service Status page. This will show you whether your service is impacted by an unplanned or planned outage and provide details on when you can expect your service to be restored.
Do you have ISDN?
You may have ISDN if you have a phone system (or PABX) at your premises. To be certain check your Telstra bill for a monthly ISDN rental charge. You can also identify ISDN by the presence of one or more Telstra branded devices between incoming lines and your phone system. The Telstra devices may be labelled as NT1 or Network Termination, with a phone number recorded on them.
Do your phone handsets have power?
If you find one or more phone handsets without power this indicates an issue with the handset, your phone system or cabling between them. Check the connection from your handset to the wall socket. Check your phone system has power. Contact a local phone system maintainer for further assistance.
Can you call internally between handsets?
If calling within your office is failing, this indicates a local issue with your phone system, rather than the ISDN line(s) into your building. Check the phone system has power, try turning it off for a minute and then on again. Contact a local phone system maintainer if the problem continues.
Are you having difficulty with handset features or system configuration?
The installer or manufacturer of your phone system should be able to provide guidance on system or handset features and operation.
Can’t find a local phone system installer/maintainer?
Telstra Business Systems may be able to help.
Are you having problems with external calls?
If calls in to and out from your business are affected you should contact Telstra ISDN support. If possible determine which phone numbers are affected and how to replicate the issue, as this will aid further investigation. Contact Telstra ISDN support anytime on 13 22 55 to raise a support request. We can assist with diverting incoming calls to another service, then perform line diagnostics and contact you back with the next steps required to resolve the issue.