/mcpDescription Setting From the drop-down list, choose one of the following options: • Non Secure—No security features except image, file, and device authentication exist for the phone. A TCP connection opens to Unified Communications Manager. • Authenticated—Unified Communications Manager provides integrity and authentication for the phone. A TLS connection that uses NULL/SHA opens for signaling. • Encrypted—Unified Communications Manager provides integrity, authentication, and encryption for the phone. A TLS connection that uses AES128/SHA opens for signaling, and SRTP carries the media for all phone calls on all SRTP-capable hops. Note If the trunks are configured with Device Security Profile option selected as Authenticated, then Unified Communications Manager starts a TLS connection that uses NULL_SHA cipher (without data encryption). These trunks will not register or make calls if the destination devices do not support NULL_SHA cipher. For destination devices that do not support NULL_SHA cipher, the trunks should be configured with Device Security Profile option selected as Encrypted. With this device security profile, the trunks offer additional TLS ciphers that enables data encryption. Device Security Mode When Device Security Mode is Non Secure, choose one of the following options from the drop-down list (some options may not display): • TCP—Choose the Transmission Control Protocol to ensure that packets get received in the same order as the order in which they are sent. This protocol ensures that no packets get dropped, but the protocol does not provide any security. • UDP—Choose the User Datagram Protocol to ensure that packets are received quickly. This protocol, which can drop packets, does not ensure that packets are received in the order in which they are sent. This protocol does not provide any security. • TCP + UDP—Choose this option if you want to use a combination of TCP and UDP. This option does not provide any security. When Device Security Mode is Authenticated or Encrypted, TLS specifies the Transport Type. TLS provides signaling integrity, device authentication, and signaling encryption (encrypted mode only) for SIP phones. If Device Security Mode cannot be configured in the profile, the transport type specifies UDP. Transport Type Security Guide for Cisco Unified Communications Manager, Release 15 and SUs 146 Basic System Security Phone Security Profile Settings