/mcpDescription Setting This field allows you to choose the authentication method that the phone uses during the CAPF certificate operation. From the drop-down list box, choose one of the following options: • By Authentication String—Installs or upgrades, deletes, or troubleshoots a locally significant certificate only when the user enters the CAPF authentication string on the phone. • By Null String—Installs or upgrades, deletes, or troubleshoots a locally significant certificate without the user intervention. This option provides no security. We recommend that you choose this option only for closed, secure environments. • By Existing Certificate (Precedence to LSC)—Installs or upgrades, deletes, or troubleshoots a locally significant certificate if a manufacture-installed certificate (MIC) or locally significant certificate (LSC) exists in the phone. If an LSC exists in the phone, authentication occurs through the LSC, regardless whether a MIC exists in the phone. If a MIC and an LSC exist in the phone, authentication occurs through the LSC. If an LSC does not exist in the phone, but a MIC exists, authentication occurs through the MIC. Before you choose this option, verify that a certificate exists in the phone. If you choose this option and no certificate exists in the phone, the operation fails. At any time, the phone uses only one certificate to authenticate to CAPF although a MIC and an LSC can exist in the phone at the same time. If the primary certificate, which takes precedence, becomes compromised for any reason, or, if you want to authenticate through the other certificate, you must update the authentication mode. • By Existing Certificate (Precedence to MIC)—Installs or upgrades, deletes, or troubleshoots a locally significant certificate if an LSC or MIC exists in the phone. If a MIC exists in the phone, authentication occurs through the MIC, regardless whether an LSC exists in the phone. If an LSC exists in the phone, but a MIC does not exist, authentication occurs through the LSC. Before you choose this option, verify that a certificate exists in the phone. If you choose this option and no certificate exists in the phone, the operation fails. Note The CAPF settings that are configured in the Phone Security Profile window interact with the CAPF parameters that are configured in the Phone Configuration window. Authentication Mode Security Guide for Cisco Unified Communications Manager, Release 15 and SUs 144 Basic System Security Phone Security Profile Settings