Skinny Client Control Protocol

SCCP is a lightweight IP-based protocol for session signaling with Cisco Unified Communications Manager, formerly named CallManager.

The call agent product is Cisco CallManager, which also performs as a signaling proxy for call events initiated over other common protocols such as H.323, and Session Initiation Protocol (SIP) for voice over IP, or ISDN for the public switched telephone network.

Other companies, such as Symbol Technologies, SocketIP, and Digium, have implemented the protocol in VoIP terminals and IP phones, media gateway controllers, and softswitches.

An open source implementation of a call agent is available in the Asterisk and FreeSWITCH systems.

[5] Twinlights Software distributes a soft phone implementation for Android-based devices.