When using a VoIP phone with the SBR-AC1200P, the SIP Passthrough option in the SBR-AC1200P 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. This document describes how to enable SIP Passthrough in the SBR-AC1200P.
NOTE:Â If it is not known if SIP Passthrough should be enabled or disabled, please contact the VoIP phone manufacturer.
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To Enable 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 Login page will appear.
 - On the Login page, enter admin in the Username field.
 - Enter password in the Password field.
 - Click the Login button.  The Home page will appear.
 
 - Move the mouse-cursor over Advanced on the main menu and click the Options link on the sub-menu.  The Advanced - Options page will appear.
 - On the Advanced Options page, under the NAT ALG Status section for SIP - Check Enable.
 - Click the Apply button.
