/mcpIf you configure both levels of authorization for SIP trunk presence requests, the BLF presence group for the SIP trunk gets used only when no BLF presence group is identified in the incoming request for the application. Before you begin Configure BLF Presence Groups, on page 532 Procedure Step 1 From Cisco Unified CM Administration, choose Device > Trunk, and click Add New. Step 2 From the Trunk Type drop-down list, select the type of phone that you want to associate BLF presence group. The value in the Device Protocol drop-down list populates automatically. Step 3 Click Next. Step 4 Configure the fields in the Trunk Configuration window. See the online help for information about the fields and their configuration options. Note To authorize the Unified CM system to accept incoming BLF presence requests from the SIP trunk, check the Accept Presence Subscription check box in the SIP Trunk Security Profile Configuration window. To block incoming presence requests on a SIP trunk, uncheck the check box. When you allow SIP trunk BLF presence requests, Unified CM accepts requests from the SIP user agent (SIP proxy server or external BLF presence server) that connects to the trunk. Consider digest authentication as optional when Unified CM is configured to accept BLF presence requests from a SIP trunk. Step 5 Click Save. What to do next Associate BLF presence group with devices and users by performing the following subtasks: • Associate BLF Presence Groups with Phone, on page 534 • Associate BLF Presence Groups with End User, on page 536 • Associate BLF Presence Groups with Application User, on page 537 Associate BLF Presence Groups with End User An administrator associates BLF presence groups with end user for user directories and call lists and to configure extension mobility settings. Before you begin Configure BLF Presence Groups, on page 532 Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 536 Presence and Privacy Features Associate BLF Presence Groups with End User