Enterprise Telephone Networks Base On NGN Technology

Next Generation Network(NGN) is packet-based network. It is capable of providing multiple services including traditional telecommunication network function. The key characters of NGN are: packet-based network, multiple services, open architecture, backward compatibility, layered service model and easy to manage. As the related technology become more and more mature, there have been commercial NGN networks deployed in Hong Kong as well as in China mainland. IP-PBX has existed for many years. But it always acts as a replacement of traditional PBX. The advantage of IP network, in which IP-PBX resides, easy to develop and deploy new features, is omitted. In this thesis, a deep study has been performed to discuss the feasibility of improving the existing IP-PBX system based on advanced NGN architecture - layered model and open application programming interface (API). The key point of the paper is dissertating how to design and make use of a set of open APIs to develop new supplementary services on existing IP-PBX. In this paper, the following area are touched:1. Introduction of NGN and IP-PBX. Introduces the background, concept and target of NGN, pointed out the source of this thesis' main theory and the arrangement of this thesis.2. Software realization. Introduces iExchange system (iExchange is a new Enterprise Switch) , brings forth the difficulty of defying open interface. Give a detailed introduction of software realization.3. Architecture of iExchange API signaling. The emphasis of this thesis is the study of iExchange API signaling. In this part thethesis detailed study the signaling header, signaling common data part and signaling private date part.4. Usage of iExchange API signaling for supplementary service. Detailed provide the signaling flow of intelligent call waiting and call transfer.Conclusion: The practice of iExchanged open API implementation has proved that it is feasible to improve existing IP-PBX with advanced NGN architecture. Introduction new NGN technology to IP-PBX development and improvement can simplify the IP-PBX implementation and provide great flexibility to develop and deploy new services.