Skinny Client Control Protocol SCCP is a proprietary terminal control protocol originally developed by Selsius Corporation . It is now owned and defined by Cisco Systems , Inc. as a messaging set between a skinny client and the Cisco CallManager . Examples of skinny clients include the Cisco 7900 series of IP phone such as the Cisco 7960 , Cisco 7940 and the 802.11b wireless Cisco 7920 . Skinny is a lightweight protocol which allows for efficient communication with Cisco Call Manager . Call Manager acts as a signalling proxy for call events initiated over other common protocols such as H.323 , SIP , ISDN and/or MGCP . A skinny client uses TCP/IP to and from one or more Call Managers in a cluster . RTP / UDP / [ [ Internet Protocol ] |IP ] is used to and from a similar skinny client or H.323 terminal for the bearer traffic ( real-time audio stream ) . SCCP is a stimulus-based protocol and is designed as a communications protocol for hardware endpoints and other embedded systems , with significant CPU and memory constraints . Cisco acquired SCCP technology when it acquired Selsius Corporation in the late 1990's . As a remnant of the Selsius origin of the current Cisco IP phones , the default device name format for registered Cisco phones with CallManager is SEP -- as in Selsius Ethernet Phone -- followed by the MAC address . Other companies like Symbol Technologies and SocketIP have implemented this protocol in VoIP Terminals ( phones ) and Media Gateway Controllers or Softswitches . A company named IPBlue has created a software phone ( soft phone ) which uses SCCP for signaling , too . This phone in fact appears to the Cisco CallManager server as a 7960 hardware phone . In addition , Cisco has come out with its own version of a skinny softphone called Cisco Unified IP Communicator . Previously , Cisco had a JTAPI/CTI version of a softphone called Cisco IP Softphone . Categories : VoIP protocols | Cisco protocols In other languages : Deutsch | Français | Română 