Call control is an important aspect of voice services that was introduced early in the development of telecommunication protocols such as Integrated Services Digital Network (ISDN), Signaling System 7 (SS7), and Session Initiation Protocol (SIP). Because these protocols provide similar call-control functions, it became desirable for a generic way of accessing them to be developed. Call Control Extensible Markup Language (CCXML) provides a generic scripting language that can performance several functions across different telecommunication protocols. CCXML enables the rapid development of new telecommunication applications that can establish communication between two or more users, and does so without requiring a developer to have a great amount of knowledge of the underlying protocols.
This paper describes the basics of CCXML as it pertains to call controls for media-based telephony applications and includes multiple examples, illustrating how CCXML can simplify inbound call handling, create outbound connections, conference multiple users, and communicate with external entities via events. This paper also provides an overview of NMS’s Vision VoiceXML Server, which allows voice application developers to rapidly develop and deploy voice- and video-based applications for converged networks.