How does an IP phone maintain its connection with the primary and secondary Cisco Unified Communications Manager servers in the cluster?

88
Cisco 642-447 Exam

A.
Cisco IP phones register with their primary server. When idle, the IP phones and Cisco Unified Communications Manager exchange the signaling application keepalives. In addition, Cisco IP phones establish a UDP session with their secondary server and exchange UDP keepalives.

B.
Cisco IP phones register with their primary server. When idle, the IP phones and Cisco Unified Communications Manager exchange the signaling application keepalives. In addition, Cisco IP phones establish a TCP session with their secondary server and exchange TCP keepalives.

C.
Cisco IP phones register with their primary and secondary servers. When idle, the IP phones and Cisco Unified Communications Manager exchange the signaling application keepalives with both servers using UDP keepalives.

D.
Cisco IP phones register with their primary and secondary servers. When idle, the IP phones and Cisco Unified Communications Manager exchange the signaling application keepalives. In addition, Cisco IP phones establish a TCP session with their secondary server and exchange TCP keepalives.

Explanation:
Incorrect answer : ACD
Link : http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/port/8_5_1/portlist851.html Explanation : To connect with DB CUCM 8.5 use TCP
Reference : Cisco Unified Communications Manager System Guide Release 8.5(1), page-562.