Research On Session Control Tochnology Based On Network Vritualization

With the popularization and development of IP network technology and mobile Internet,multimedia communication based on IP network has been rapidly developed.As the core media communication protocol of next-generation networks,the SIP protocol has been widely used in real-time voice,live video,and VoLTE.Therefore,SIP protocol research has quite high application value.Compared with the traditional Internet,it is characterized by virtualizing the network and separating control and forwarding,which can better meet the development needs of the future network.Researching and implementing the session system on the SDN platform do not have various limitations in the traditional network.It can use the new network technology in the SDN to solve the shortcomings of the traditional network session,and design a more flexible and efficient session system to provide users with better service.There are two research focuses in this paper.One is to solve two technical problems of VoIP systems in traditional networks,client plug-and-play and client network traversal.Among them,the client plug-and-play securely transmits the user's password to the server by modifying the SIP registration process and using RSA encryption and decryption.The server creates and saves the user's account so as to realize the automatic opening account through the client's account,simplifying the original complexity of adding new users to the SIP system.The client network traversal based on the establishment of the original SIP session packages and uses the ICE implementation of the PJNATH open source library,completing the function of the SIP client network traversal,and realizing the normal transmission of the media stream under the NAT environment.These two technical problems involve the modification of SIP registration and call flow,as well as the processing of SIP header fields and SDP,laying the foundation for subsequent session control research under the SDN environment.The second is to analyze the existing problems in the VoIP communication system in the traditional network,and to connect existing network virtualization and SDN technology to improve the network,designing a SDN-based VoIP communication system session control method.Through the session control and resource management of the SDN controller,the network resource query and reservation functions before establishing the session as well as the server relay transcoding function have been realized.Based on the above expansion of the system,the system's service quality and service capability are improved without modifying the client.This paper firstly introduces the relevant technical background of SIP protocol and network virtualization.And then two problems of the traditional VoIP system in the network are researched.Sequentially,the SDN-based VoIP communication system session control method is analyzed and designed.After setting up the test environment,this study tests the previous research and analyzes the results.Finally,a summary of this study would be drawn and suggestions for the future research is proposed.