Which two signaling protocols does Cisco Unified Communication Manager support for the Cisco IP phones? (Choose two)

Cisco Unified Communication Manager (CUCM) supports two primary signaling protocols for its IP phone endpoints. The first is the Skinny Client Control Protocol (SCCP), a lightweight, Cisco-proprietary protocol originally developed for Cisco IP phones. The second is the Session Initiation Protocol (SIP), an open-standard IETF protocol that has become the industry standard for VoIP signaling. CUCM can register and manage Cisco IP phones running either SCCP or SIP firmware, allowing administrators to choose the protocol that best fits their network and feature requirements.

B. H.323: H.323 is a signaling protocol suite primarily used by CUCM for communication with gateways and for trunks to other IP-PBX systems, not for IP phone registration.
C. MGCP: Media Gateway Control Protocol (MGCP) is used by CUCM to control and manage media gateways, such as analog voice gateways, not for IP phone signaling.
D. RTP: Real-time Transport Protocol (RTP) is a transport protocol used to carry the actual voice and video media streams, not a signaling protocol for call setup or control.

1. Cisco Collaboration System 12.x Solution Reference Network Design (SRND)

Reference: Chapter: "Unified CM Endpoints", Section: "Endpoint Protocols"

Content: "Cisco Unified CM supports a wide variety of endpoint types, including Session Initiation Protocol (SIP), Skinny Client Control Protocol (SCCP), and Java/XML and HTML-based applications. Most Cisco endpoints are available with either SIP or SCCP firmware loads." This directly confirms that SIP and SCCP are the supported protocols for endpoints (phones).

2. System Configuration Guide for Cisco Unified Communications Manager, Release 14

Reference: Chapter: "Cisco Unified IP Phone Configuration", Section: "Phone Configuration Checklist"

Content: The guide details the configuration steps for adding new phones to CUCM. In the "Phone Configuration" window, a mandatory field is "Phone Button Template," which is associated with a specific protocol (SCCP or SIP). Furthermore, the "Device Protocol" field for many phone models explicitly allows the selection of either SIP or SCCP, confirming both are supported.

3. Cisco Unified Communications Manager Administration Guide, Release 12.5(1)SU1

Reference: Chapter: "Device Settings", Section: "Phone Button Template Configuration"

Content: "Phone button templates are associated with a specific phone model and protocol (SCCP or SIP). Cisco Unified Communications Manager comes with a default set of phone button templates for each phone model and protocol." This statement from the official administration guide confirms that CUCM manages phones based on either the SCCP or SIP protocol.