Service control in IMS architecture is delegated to the Service Capability Interaction Manager. The SCIM coordinates the diverse capabilities from different service domains using SIP as the control protocol in the signaling layer. The SCIM can be likened to a SIP-based AS that performs the functionality of runtime orchestration of interactions between capabilities in the converged network. Such interactions can occur between SIP features and legacy signaling features such as SS7, between components that are wholly implemented as SIP proxies or user agents, or even with external business capabilities that are exposed using Web services.