When using a VoIP phone with the SBR-AC1750, the SIP Passthrough option in the SBR-AC1750 may need to be enabled in order for that phone to have full functionality. Â In other situations, it may be recommended by the VoIP phone manufacturer to disable SIP Passthrough. Â By default, SIP Passthrough is enabled. Â This document describes how to enable SIP Passthrough in the SBR1750.
NOTE: If it is not known if SIP Passthrough should be enabled or disabled, please contact the VoIP phone manufacturer.Â
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To Enable SIP Passthrough
- Launch a web browser, such as Internet Explorer, Firefox, or Safari. Â Enter http://192.168.0.1 into the address box and press the Enter key. Â The Login page appears.
NOTE: By default the LAN IP address is 192.168.0.1. Â If the default address has been changed, enter the custom address in the address box.
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 - On the Login page:
a. Â Enter password in the Password field.
b. Â Click the Login button. Â The Home page appears.
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 - Move the mouse-cursor over the Firewall tab and select the ALG sub-link.  The Firewall - Application Layer Gateway Settings page appears.
- On the Firewall - Application Layer Gateway Settings page:
a. Â SIP - Check mark the box.Â
b.  Click the Apply button.
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