/mcpSubscribe Devices to Extension Mobility Enable Extension Mobility on devices and subscribe to the service if you have not set up an enterprise subscription for all devices. Procedure Step 1 From From Cisco Unified CM Administration, choose Device > Phone. Step 2 Find the phone on which users can use Extension Mobility Cross Cluster. Step 3 For this device, check the Enable Extension Mobility check box in the Extension Information pane. Step 4 In the Phone Configuration window, choose the Subscribe/Unsubscribe Services option in the Related Links drop-down list. Step 5 Click Go. Step 6 In the popup window that opens, choose the Extension Mobility service in the Select a Service drop-down list. Step 7 Click Next. Step 8 Click Subscribe. Step 9 From the popup window, click Save, and then close the window. Step 10 In the Phone Configuration window, click Save. Step 11 Click OK if prompted. Configure Certificates for Extension Mobility Cross Cluster To configure the home and remote clusters properly, you must export certificates on each cluster to the same SFTP server and SFTP directory and consolidate them on one of the participating clusters. This procedure ensures that trust is established between the two clusters. Before you begin Configure Extension Mobility, on page 423 Procedure Purpose Command or Action Activate the Bulk Provisioning Service, on page 433 Step 1 Configure bulk certificate management in Cisco Unified OS Administration to export the Configure Bulk Certificate Management and Export Certificates, on page 433 Step 2 certificates from both the home and remote clusters. Consolidate certificates when all participating clusters have exported their certificates. This Consolidate the Certificates, on page 434 Step 3 Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 432 Receiving Calls Subscribe Devices to Extension Mobility