When using a VoIP phone with the SBG8300, the SIP Passthrough option may need to be enabled in order for that phone to have full functionality. In other situations, it may be recommended by the VoIP phone manufacturer to disable SIP Passthrough. By default, SIP Passthrough is enabled. If it is not known if SIP Passthrough should be enabled or disabled, please contact the VoIP phone manufacturer. This document describes how to disable SIP Passthrough in the SBG8300.
NOTE: The ALG sub-menu link is available on firmware version 01.02.078.04.NCS and later.Â
Disable SIP Passthrough
- Launch a web browser, such as Internet Explorer, Firefox, or Safari.  Enter http://192.168.0.1 into the address box, and press the Enter key.  The https:// Redirect page will appear.  Â
 - The SURFboard Web Manager is begin redirected to a more secure connection, click the Proceed button to continue.  The Gateway > Login page will appear.
 - A security or private risk alert may appear on the web browser advising users to proceed with caution when accessing the Web Manager. There is no risk in proceeding to the Web Manager. For instructions to by-pass the alert screen, refer to article # 18181 - Alert Message for Web Manager Access.
NOTE: The Home Network Wizard will appear if this is the first time accessing the Web Manager. For assistance with the wizard, refer to article # 17969 - SBG8300: Web Manager First Time Login.
 - Enter admin in the Username field and enter the custom password in the Password field.
NOTE: If the Login page prompts for email address and password. Log into the Web Manager with the email and password used when setting up the SURFboard Manager app with the SBG8300.
 - Click the Login button.  The Gateway > Summary page will appear.
 - On the Left-hand menu, click the Advanced link, then click the ALG sub-menu link.  The Advanced > ALG page will appear. Â
 - Uncheck the SIP box, then click the Save Settings button.
