D-Link DPH-128MS User Manual page 86

Section  - Installation
• UPnP Setting
UPnP: Enable or disable the UPnP function.
• NAT Keep Alive Time Settings
Always Send Keep
Enable or disable the function to send the lightweight packets for keeping the tunnel that is established by NAT
Alive Packet:
router for SIP signaling.
Keep Alive Time:
The time period that the VoIP phone sends out the lightweight packets for keeping the tunnel alive.
Click Submit to save and activate the changes, or Reset to restore the configurations.
D-Link DPH-18MS User Manual 8