services. Figure 2.1 shows an example of service implementation that automat- ically answers incoming calls and ends its execution when the caller hangs up. As depicted in Figure 2.2, several entities can appear in a CCXML session: Connection. It represents the endpoints of a communication Conference. It manages the mixing of audio video streams when there are several participants in a multiconference Voice Dialogs. They are associated with an existing Connection or Con- ference and they allow executing media actions in a media server, for example, music on hold, DTMF, IVR, Early Media, etc CCXML brings Web and XML advantages to call control and provides advan- ced call control features that VoiceXML lacks. It allows flexible development © 2009 by Taylor & Francis Group, LLC SIP: Advanced Media Integration CCXML session Conference Dialog Connection FIGURE 2.2 CCXML entities. of applications such as multi-party conferencing, call center integration, and follow me and find me services. Its main features are: Basic call control features such as answer, create call, disconnect, reject, and redirect JCC/JAIN-based call model Flexible asynchronous event model Multi-party conferencing IVR/Dialog integration (VoiceXML, SALT, among others) 2.2.1.2 MSCML The Media Server Control Markup Language (MSCML) is an IETF RFC proposal aimed at enabling enhanced conference control functions such as muting individual callers or legs in a multi-party conference call, the ability to increase or decrease the volume, and the capability of creating sub-conferences. MSCML also addresses other feature requirements for large-scale conferencing applications, such as sizing and resizing of a conference. MSCML implements a client server model to perform the media control server. 2.2.1.3 MSML The Media Session Markup Language (MSML) is an IETF Draft proposed as an extension to SIP that aims to control media servers with dialogs through a master-slave scheme. MSML makes use of XML content in the message bodies of SIP INVITE and INFO requests, wit