Which of the following ports can UCM use to communicate with an IP phone if the phone supports only SIP for
call signaling? (Select the best answer.)
A.
TCP port 2000
B.
UDP port 2427
C.
TCP or UDP port 5060
D.
TCP port 6970
E.
UCM will be unable to communicate with the IP phone.
Explanation:
Cisco Unified Communications Manager (UCM) can use Transmission Control Protocol (TCP) port 5060 or
User Datagram Protocol (UDP) port 5060 to communicate with an IP phone if the phone supports only Session
Initiation Protocol (SIP) for call signaling. The signaling conversation between UCM and an IP phone controls
many of the IP phone’s functions, such as call initiation, call termination, and call waiting notification. UCM can
have multiple, simultaneous signaling conversations with IP phones using different protocols. For example,
UCM can use SIP to communicate with one IP phone and use Skinny Client Control Protocol (SCCP) to
communicate with another IP phone on the same network. SCCP uses TCP port 2000.
UCM does not use UDP port 2427 or TCP port 6970 to communicate with an IP phone for call signaling. Media
Gateway Control Protocol (MGCP) uses UDP port 2427 for gateway control messages. IP phones can use TCP
port 6970 to download firmware and configuration files from UCM.https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/port/9_1_1/CUCM_BK_T2CA6EDE_00_tcp-portusage-guide-91/CUCM_BK_T2CA6EDE_00_tcp-port-usage-guide-
91_chapter_01.html#CUCM_TP_P019EF1A_00