Create new services, in a faster way and at lower costs in order to attract new customers, keep existing ones and increase revenue, is the great target for telecom operators. This is possible with concepts like Next Generation Networks (NGNs), Service Delivery Platforms (SDPs) and Service Oriented Architecture (SOA), due to they enable the integration of the Telecommunications and Information Technologies (IT) domains. However, the telecom operators of non-developing countries have a limited knowledge about the technologies that adapt better to their needs, and how they can be used and integrated into their networks for Value-Added Services (VAS) provisioning. Therefore, a set of technical criteria that supports telecom operators in non-developing countries for VAS creation, execution and deployment, is proposed in this paper. In the same way, a general scheme for the establishment, description and definition of technical criteria is proposed under the context of NGN telecom operators with Softswitch in the control layer (without IP Multimedia Subsystem (IMS) control layer). Then, the Color/Caller Ring Back Tone (CRBT) as VAS, is developed for testing the general scheme and the technical requirements proposed. For this matter, Rhino Service Logic Execution Environment (SLEE) (Java Application Programming Interface (API) for Integrated Networks (JAIN) SLEE 1.1 specification compliance) was used. Furthermore, the results of CRBT integration into a real environment (NGN of EMCALI Colombian telecom operator) are presented. Finally, some conclusions are presented.