 taken in the layout of the network architecture, several functions have been identified as being necessary for a SCIM. Before the SCIM can control any service interactions or AS, it needs to have some form of knowl- edge about these services. It also needs to have some mechanism to cope with the detected conflicts. Almost all the approaches covered here use the standard diameter interface with the HSS to download user information (the user's IMS profile). However, we are more interested in how these systems handle the information about each service. Service Orchestration in the IP Multimedia Subsystem Gouya et al. [12] propose using a "formal model of all the services [the SCIM] may trigger. This formal model would [make] explicit the decomposition of a ser- vice into service capabilities and the interactions needed between service capabili- ties and the end-users." This would be classed as an offline conflict detection mechanism, and while it has a high level of control over the service interactions, it is not ideal because as the number of services increase this model would need to be updated. The extension of this system to perform in a dynamic way has been identi- fied by Gouya et al. [12] as an area requiring future work. They state that "increased diversity in the domain of next generation services" demands that the "extension of the service capability interaction rules must be performed in a dynamic way to facilitate the introduction of new services" [12]. Nakajima et al. [13] make a distinction between two main types of services to make detecting and resolving conflicts easier. The separating factor between these two groups is the amount of call control that the service exhibits. Where there is a large amount of call control the services are classed as "Connection Control Applications." An example of a Connection Control Application would be a "Click- to-Dial" application. This is where the end user visits some mechanism, for example a Web page that allows him to establish a voice call. He would click on