The SkyLink device has 2 incoming Iridium phone lines. It is possible that you are not receiving call notifications because the SIP extension you are using is not configured to receive incoming calls from the Iridium line you are calling.
In the SkyLink Web Interface:
- Navigate to the Voice Extensions screen
- Click ‘Edit’ on your extension
- Ensure that both boxes in the Inbound Line(s) field are ticked, then click ‘Save.’