All these methods require the Message Waiting notification to be configured as SIP or SIP+PMS.
From Mailbox Administration→Templates→Notifications.
Set both the MWI On and MWI Off template to use SIP or SIP + PMS if you prefer.
Often if the PBX doesn't supply forwarding of message waiting to a phone or is blocked because it has it's own voicemail the DuVoice can send a SIP notify directly to the phone or gateway.
Care should be taken to ensure the PBX never sends a SIP Notify to the extension otherwise the light may not be in the correct state.
Edit a mailbox, choose Address List, and configure one or more of the MWI addresses for the SIP address you wish to send the notification.
When using a SIP gateway to connect analog phones, many support the ability to address an extension directly allowing the DuVoice system to send a SIP notify to the gateway.
Some Gateways only use use the gateway IP address for each port while others like the Grandstream GXW4224V2 use the IP address and a port number for each jack. In the case of the Grandstream
Only the extension @ gateway IP address is required **Example** 3101@192.168.100.243