Design And Implementation Of VoIP System Based On A Saftey Protocol

With the high development of the Internet,VoIP has become a special communicationtechnology,and it will be used more and more widely. Except service quality problems, theclients have a high requirements for the safety of VoIP, especially the clients that deal withsensitive information, include the banks,the governments and so on.They have faced somesevere threats,like wiretap and attack.So how to ensure the safety of both communicationhas become a important subject of VoIP field.Based on the problems above, we raise the secure calls based on SIP protocol andSRTP protocol to fulfil the safety of the VOICE section of the8048ROUTER.The wholesystem is based on linux environment and actualized in Comware V7platform.The Voicesystem is made up of CMC,DPL,SIP,MSC,LGS and so on.Analysis of the whole VoIPsystem,we need to implement the work above in MSC module and SIP module. SIPmodule use the SIP protocol to negotiate different kinds of SIP calls like basic call,securefallback call,trunk and so on.SIP message take the SDP message to negotiate all kinds ofmedia information to build session information. MSC module manages the transmission ofRTP,RTCP message, and based on SRTP protocol to implement the messages’encryption.The system is based on SIP protocol and SRTP protocol.We analyse the voiceprocess,except the basic secure calls,it will support a more comprehensive business.Weoptimizate the negotiation and the media transmittion,and support more cases about thesafty of the media stream,and in accordance with the unsecure call performanceconfiguration, the secure call performance meet the needs of the voice quality.