Design And Implementation Of Doubango Framework Extension And Application Based On IOS Operating System

With the rapid development of mobile Internet,the popularity of intelligent terminal equipment and 4G licenses have been issued,VoIP business is facing huge business opportunities.Meanwhile,in the open network environment,the security of IP telephony and voice quality also put forward higher requirements,for the majority of developers will be a big challenge.In order to enable developers to easily develop a high safety,good voice quality of IP phone applications,this paper extension the design of third party SIP protocol stack Doubango open source frameworks,and realize the IP telephone function based on the iOS platform.This paper firstly study and research on several key technologies and protocols involved in VoIP.Then the protocol stack structure and the module composition of the Doubango open source framework are analyzed in detail.After that,for how to ensure the security of VoIP communication and combined with SIP common attacks,this paper proposes an improved scheme based on HTTP digest authentication mechanism,and add the end to end authentication to ensure the security of the Doubango framework.In addition,this paper proposes a packet loss compensation mechanism for the Doubango framework to guarantee the quality of speech.Using the software engineering method,combined with the requirements of the software,the overall design,architecture design and detailed design of the client are completed.In this paper,based on the idea of hierarchical structure design,UI layer and business layer separation,greatly reduce the program coupling,individual developers can directly carry out the development of the third party based on the middle of the service layer.This paper designed and implemented the client with user registration,voice calls,instant messages,contacts and call history,and other functions,and optimized under iOS8,having good user experience.