If you're unable to make calls inbound or outbound try rebooting your phone system by removing the power cable or switching it off at the power point, wait 10 seconds and power back up.
The arrows below are an example of the power cord locations, for an eMG80 phone system the power cord is on the left hand side of the unit, for an iPECS or UCP phone system there is a small power cord located on the front of the unit here, or a larger power cord is located on the back. The unit to reboot will have written on it either UCP100, MFIM50A, MFIM50B, MFIM100 or something similar.
If you're having issues with just one handset try swapping the handset with another of the same model to determine if it is the handset or the data socket that is faulty. If you have no audio or it is crackly try swapping the curly cord and handpiece with another handset to see if this resolves the issue. For user guides and more information click here.
Internet - NBN/ADSL
If you can't browse the internet or connect to your WIFI the first step is to reboot router, for most routers there is a small power switch located on the back, press this and wait about 10 seconds then press again to power on. if you have a 4G dongle for failover and you have an NBN fault you may need to manually reboot your router to connect to the 4G service.
4G failover dongle