The Design And Realization Of SIP-based VoIP Security Terminal

With the rapid development of internet technology in the direction of digital, integrated. The Internet has deeply influenced the people’s daily life and work.Provide voice, fax, video, data and other multimedia services through IP network has become the development trend and target of real-time communication.This technology which provides real-time information communication through the network IP,has become the important means of communication with the further popularization of network application.However, as the medium of VoIP transmission, the IP network currently exists a lot of security risks. It is that IP data packets on the network is very likely being intercepted by hackers, resulting in a serious consequence that part of important information is lost or tapped.The target of design which presented in this thesis is to realiazean VoIP security terminal withSoCchip, and provide voice-call function for people based on the platform is realized. Provides protection for VoIP communication based on encryption of RTP message.The related technologies involved in VoIP were firstly analyesd and researched in the thesis.After that, it analyses several kinds of popular technologies in signaling control and Data encryption fields. SDP for media parameters negotiation, and RTP for voice data real-time transporting.VoIP security terminal is realiazedwith SIP for basic control protocol and AES for data encryption. Then carry out the research on SIP protocol, AES algorithm authentication mechanism and encoding rules based on the platform. Based on these researches, the design and realization of VoIP security terminal was achieved.The design tasks are composed of hardware design and software design. The software section includes transplantation of the SIP protocol stack, driver development, design and debugging of identity authentication mechanism. The hardware section includes the selection of SoC, design of principle block diagram and peripheral circuit, and the implementation of AES algorithm based on FPGA. This paper introduces in detail the design of the hardware circuit and software code, debugging process, and from the results, such as line caught way to achieve the terminal based on SIP protocol of VoIP security testing.Finally,we built a set of test network based onopen source SIP server.and access the test network with Sip-Based VoIP Security terminal.Inthe test network,we tested the call function of VoIP security terminal,andverfified the security of VoIP communication through network packet capture.