To disable SIP inspection in the ASA, you need to navigate to “Configuration” then “Firewall” then highlight “Service Policy Rules.”
Once in “Service Policy Rules” you highlight the default inspection policy by left clicking on it and then choose the “Edit” button at the top. This will open a new window. At the top, click on the “Rule Actions” tab. Scroll down until you see “SIP” option and then UN-CHECK the option and hit “Ok” then click the “Apply” button at the bottom.