and provisioning is a flexible service framework for implementation of value-added services using network capabilities. These capabilities are accessed via standard application interfaces. The NGN Release 1 supports the following classes of value-added service environments: IN-based service environment (INAP, CAMEL, WIN, ) IMS-based service environment Open service environments (OSA/Parlay, Parlay X, OSE) These new services either reside in the user's home network or in a third-party location. The ASs of the IMS-based service environment may influence and impact the SIP session controlled at the S-CSCF on behalf of the services supported by the operator's network, or may host and execute services. Hereby, the ASs can be SIP AS, which may host and execute services. OSA AS, which does not directly interact with the IMS network entities but through the OSA Service Capability Servers (SCSs). The OSA framework provides a standardized way for third-party access to the IM Subsystem. Enabling Service Delivery in Next-Generation Networks CAMEL IM-SSF whereby the CAMEL network feature enables the use of operator specific services by a subscriber even when roaming outside the home network. For details at the NGN service provisioning architecture governed via the IMS, please refer to the respective technical specification of the 3GPP TS23.002 [2]. 4.2.2.1 Third-Party Access via OSA/Parlay Value-added service creation via standardized APIs to network services is the commonly understood way to develop and deploy new services over network service architectures. The Parlay Group [3] is a consortium formed to develop open, technology-independent APIs that enable the development of applications that operate across converged networks. Parlay integrates Internet multimedia networks and intelligent networks (IN) with IT applications via a secure, measured, and billable interface and has been widely deployed in Telecoms networks globally. The goal of Parlay was to enable the creation of vast numbers of new applications in and around t