Which protocoldoes Jabber use to communicate with the Cisco IM and Presence server when instant messages are sent and received?

MSNP is Microsoft's proprietary network protocol used historically by Windows Live Messenger and is not used by Cisco Jabber or IM and Presence.

SIMPLE (SIP for Instant Messaging and Presence Leveraging Extensions) is a SIP-based IM protocol not used for Jabber-to-IM&P communication, though IM&P can federate with SIMPLE-based systems.

XMPP is the open-standard protocol natively used by Cisco IM and Presence Service and Jabber for real-time instant messaging and presence updates; Jabber establishes an XMPP connection to the IM and Presence server on TCP port 5222 to exchange messages and subscription state.

OSCAR is AOL's proprietary instant messaging protocol used by AIM and ICQ and has no role in Cisco UC architecture.