| With the rapid development of computer and communication technology, the number and the kind of the service we need is growing as well, which made softswitch, the main technology of NGN, has been paid more attention. The essential feature of softswitch is the separation of services, control and transmission, which made softswitch can make use of previous resources, at the same time, the capability of softswitch network can get better and the service scalability is more powerful. These advantages has been made full use of by IP-PBX, which made the communication in corporation become more economical and convenient.At the beginning of this paper, we described the overview,technology features and trends in the future of softswitch, we analyzed the architecture of softswitch in detail, and do some further discussion about related references, such as H.323, SIP, etc. Next, we proposed the model of IP-PBX system, bring up the needs of IP-PBX, and researched the network composition. Further more, we elaborated the open source Asterisk specifically, which has good flexibility and scalability. In order to achieve the service expansion of IP-PBX, we should open appropriate architecture and interface, load and configure some related plugins and modules. After that, we analyzed the selection of software and hardware, designed a flexible IP-PBX. We focuses on control module and access module, studied the construction, process and implementation of those modules, researched how to transfer voice, data and multimedia between different protocols, and how to compile dialplan. Last, we designed test cases, and test the IP-PBX, which can transmit multimedia between two terminals successfully. |
PDF Full Text Request