When Cisco Unity Express is integrated with Cisco CallManager, which protocol handles Message Waiting Indication?

SIP handles call signaling and session setup between endpoints but is not the protocol CUE uses to trigger MWI events on phones registered to Cisco CallManager.

VPIM (Voice Profile for Internet Mail) is a standard for exchanging voice messages between disparate voicemail systems over IP networks, not for signaling MWI status.

JTAPI (Java Telephony Application Programming Interface) is the CTI protocol that Cisco Unity Express uses to communicate with Cisco CallManager to turn the MWI lamp on and off on subscriber phones. CUE uses a dedicated JTAPI user account configured on CallManager to send MWI on and off notifications whenever a voicemail is deposited or retrieved from a mailbox.

MIME (Multipurpose Internet Mail Extensions) is an email format standard used to encode message attachments and body types, with no role in MWI signaling.

VoIP is a broad umbrella term for voice-over-IP technology and does not identify a specific protocol responsible for MWI in a CUE-CallManager integration.

IMAP is an email retrieval protocol used by clients to access messages on a mail server and plays no part in MWI signaling between CUE and CallManager.