/mcpProcedure Purpose Command or Action (Optional). Configure the Prime Line Support feature for the Cisco CallManager service, which applies to the entire cluster. Configure Clusterwide Prime Line Support, on page 324 Step 1 (Optional). Configure the Prime Line Support feature for specific devices within the cluster, Configure Prime Line Support for Devices, on page 325 Step 2 if you do not want to enable the feature clusterwide. Note When you configure this parameter, going off-hook makes only the first line active on the phone, even when a call rings on another line on the phone. So the call does not get answered on the other line. Configure Clusterwide Prime Line Support Procedure Step 1 From Cisco Unified CM Administration, choose System > Service Parameters. Step 2 From the Server drop-down list, choose the server that is running the Cisco CallManager service. Step 3 From the Service drop-down list, choose Cisco CallManager. Step 4 From the Always Use Prime Line clusterwide service parameter, choose one of the following options from the drop-down list: • True- When a phone goes off-hook, the primary line gets chosen and becomes the active line. • False- When a phone goes off-hook, the IP phone automatically chooses an available line as the active line. The default value for this service parameter is False. Step 5 For this change to take effect on the SIP phones, click the ApplyConfig button in Cisco Unified CM Administration (for example, on the Device Configuration window, the Device Pool Configuration window, or any other window on which ApplyConfig is an option). Note If the new configuration is not applied on the SIP phones, the SIP Prime Line Support feature changes will not be implemented until the next reset of the Cisco CallManager service or reset of each affected device. Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 324 Receiving Calls Configure Clusterwide Prime Line Support