Session Initiated Protocol (SIP) Application Level Gateway (ALG) is enabled by default on a D-Link router. This feature allows automatic response to VoIP connection and opens appropriate application ports. This is useful for outgoing VoIP calls.
This article will guide you on how to disable this feature on a D-Link router.
IMPORTANT: Changing your router's configuration is critical. For more information in configuring your router's settings, contact your router manufacturer for advanced support.
Accessing the router interface
Enter the router's IP address in the address bar of your web browser.
NOTE: To check your router's IP address on a Windows computer, follow the steps below:
Access the command prompt by pressing the Windows key + R.
Enter "cmd" then press [Enter].
Type in IPCONFIG then find the Default Gateway.
Type in the Administrator’s Username and Password in the authentication screen.
NOTE: The default username and password for a D-Link router is:
Username: admin or Admin
Configuring the router
Click Firewall Settings.
Uncheck the box for Enable SPI.
Switch the radio button on NAT Endpoint Filtering
to Endpoint Independent
for both UDP
Uncheck the SIP box for Application Level Gateway (ALG) Configuration.
Click Save to save settings.