- Skinny Call Control Protocol
SCCP (Skinny Call Control Protocol) 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 CiscoCallManager . Examples of skinny clients include the Cisco 7900 series of IP phone such as theCisco 7960 ,Cisco 7940 ,Cisco IP Communicator softphone and the802.11b wireless Cisco 7920, along withCisco Unity voicemail server. Skinny is a lightweight protocol which allows for efficient communication with CiscoCallManager . [ [http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a0080624977.shtml Call states sent to SCCP endpoints by Cisco CallManager] ] CallManager acts as a signaling proxy for call events initiated over other common protocols such asH.323 , SIP,ISDN and/orMGCP .A skinny client uses
TCP/IP to and from one or more Call Managers in a cluster. RTP/UDP/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 1998. [ [http://newsroom.cisco.com/dlls/fspnisapi6d14.html Cisco Systems acquisition of Selsius Systems] ] 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 andSocketIP have implemented this protocol inVoIP Terminal s (phones) andMedia Gateway Controller s orSoftswitch es. Open Source implementations of SCCP/Skinny exist and are now part of theAsterisk (PBX) system.A company named [http://www.ipblue.com/ IPBlue] has created a software phone (
soft phone ) which uses SCCP for signaling, too. This phone in fact appears to the CiscoCallManager server as a 7960 hardware phone.In addition, Cisco has come out with its own version of a skinny softphone called Cisco IP Communicator as well as SIP-based softphone called Cisco Unified Personal Communicator. Previously, Cisco had a JTAPI/CTI version of a softphone called Cisco IP Softphone.
References
External links
[http://www.cisco.com/en/US/tech/tk652/tk701/tk589/tsd_technology_support_sub-protocol_home.html Skinny Call Control Protocol (SCCP) - Cisco Systems]
[http://hisown.com/Talks/VoIP%20-%20Excerpt%20(SCCP).pdf Skinny Call Control Protocol (SCCP) - Fragment of a VoIP course dealing with SCCP, with sample captures]
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