Cisco IM and Presence Protocol for Phone State Presence Information Exchange

C.

To provide interoperability between communications systems, SIP is the protocol leveraged.

Enterprise Presence solutions need to provide for a uniform definition of the main communication services such as IM, voice, video, e-mail, web calendaring, and so on, while SIP delivers the necessary features.

The protocol that is used between Cisco IM and Presence and Cisco Unified Communications Manager for the exchange of phone state presence information is the Session Initiation Protocol (SIP) and the SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE) protocol.

SIP is a signaling protocol used for establishing, modifying, and terminating real-time sessions that involve video, voice, messaging, and other communications applications and services. SIP is widely used in IP telephony, Voice over IP (VoIP), and Unified Communications (UC) solutions.

SIMPLE is a protocol that extends SIP to include presence and instant messaging capabilities. SIMPLE allows users to indicate their availability, status, and location information in real-time, enabling efficient communication and collaboration. SIMPLE also provides a mechanism for exchanging instant messages between users.

In the context of Cisco Unified Communications Manager and Cisco IM and Presence, SIP and SIMPLE are used to exchange phone state presence information. This information includes whether a user's phone is ringing, busy, idle, or in Do Not Disturb (DND) mode. The presence information is used by the Cisco IM and Presence system to determine the user's availability and status, which is then used by the system to route calls and messages appropriately.

In summary, the correct answer to the question is C. SIP/SIMPLE.