/mcpDescription Setting Application-level authorization applies to applications that are connected through the SIP trunk. If you check this check box, you must also check the Enable Digest Authentication check box and configure digest authentication for the trunk. Unified Communications Manager authenticates a SIP application user before checking the allowed application methods. When application level authorization is enabled, trunk-level authorization occurs first, and application-level authorization then occurs, which means that Unified Communications Manager checks the methods that are authorized for the trunk (in this security profile) before the methods that are authorized for the SIP application user in the Application User Configuration window. Tip Consider using application-level authorization if you do not trust the identity of the application or if the application is not trusted on a particular trunk; that is, application requests may come from a different trunk than you expect. Enable Application Level Authorization If you want Unified Communications Manager to accept presence subscription requests that come via the SIP trunk, check this check box. If you checked the Enable Application Level Authorization check box, go to the Application User Configuration window and check the Accept Presence Subscription check box for any application users that are authorized for this feature. When application-level authorization is enabled, if you check the Accept Presence Subscription check box for the application user but not for the trunk, a 403 error message gets sent to the SIP user agent that is connected to the trunk. Accept Presence Subscription If you want Unified Communications Manager to accept incoming non-INVITE, Out-of-Dialog REFER requests that come via the SIP trunk, check this check box. If you checked the Enable Application Level Authorization check box, go to the Application User Configuration window and check the Accept Out-of-Dialog Refer check box for any application users that are authorized for this method. Accept Out-of-Dialog Refer If you want Unified Communications Manager to accept incoming non-INVITE, unsolicited notification messages that come via the SIP trunk, check this check box. If you checked the Enable Application Level Authorization check box, go to the Application User Configuration window and check the Accept Unsolicited Notification check box for any application users that are authorized for this method. Accept Unsolicited Notification Security Guide for Cisco Unified Communications Manager, Release 15 and SUs 190 Basic System Security SIP Trunk Security Profile Settings