/mcpConfigure Prime Line Support for Devices Procedure Step 1 From Cisco Unified CM Administration, choose Device > Common Phone Profile. Step 2 From the Find and List window, choose the phone for which you want to change the Always Use Prime Line setting. The Phone Configuration window appears. Step 3 From the Always Use Prime Line drop-down list, choose one of the following options: • Off- When the phone is idle and receives a call on any line, the phone user answers the call from the line on which the call is received. • On- When the phone is idle (off hook) and receives a call on any line, the primary line is chosen for the call. Calls on other lines continue to ring, and the phone user must select those other lines to answer these calls. • Default- Unified Communications Manager uses the configuration from the Always Use Prime Line service parameter, which supports the Cisco CallManager service. Step 4 Click Save. Prime Line Support Interactions Interaction Feature If you select On for the Always Use Prime Line parameter in the Device Profile or Default Device Profile Configuration window, a Cisco Extension Mobility user can use this feature after logging in to the device that supports Cisco Extension Mobility. Always Use Prime Line When the phone already has a call on a line, Unified Communications Manager uses the configuration for the Maximum Number of Calls and Busy Trigger settings to determine how to route the call. Maximum Number of Calls and Busy Trigger Settings If you choose the Auto Answer with Headset option or Auto Answer with Speakerphone option from the Auto Answer drop-down list in Cisco Unified CM Administration, the Auto Answer configuration overrides the configuration for the Always Use Prime Line parameter. Auto Answer Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 325 Receiving Calls Configure Prime Line Support for Devices