Research And Improvement Of SIP Signaling Compression Algorithm Based On Pjsip

With the integration of Internet network and wireless communication network,a great number of of IP network protocol which originally used on the Internet,have been referenced to the wireless network.For example,SIP protocol has been widely used to provide IP multimedia services,and has achieved great success in the streaming media market.However,The SIP protocol has some drawbacks in the current scenarioof streaming media application.SIP is such a protocol which based on text,originally designed for a bandwidth-rich Internet network environment.So the length of message is not optimized well,which cause the length of SIP message ranging from hundreds to thousands of bytes.If the SIP protocol is used in mobile communications,the transmission delay will be very obvious and the time of establishing the session will extended obviously.In face of the problem of the length of transmitting text is too long,this paper proposes a method based on LZ77 compression algorithm to compress the SIP message lossless,which lead to shorten the time of setting session and reduce the transmission delay.The main work of this article is listed as follows:(1)First,we introduce the theoretical principle of SIP protocol,and elaborated its calling process;Then,the advantages and disadvantages of several common text compression algorithms are compared.Combined with the characteristics of SIP message itself,the LZ77 algorithm is selected becauseit is the most suitable for SIP signaling compression.Next,(2)Secondly,The concept and principle of the compression algorithm are introduced.Finally,a complete set of network communication experiment platform is built to achieve video Conversation between clients based on pjsip protocol stack After using the platform for a great number of testing,the data is collected and the results are analyzed and compared..it can be concluded that the compression algorithm performs well and the practicability of the scheme is validated.Through the calculation,using the compression algorithm,the time of setting session reduced by nearly 10% compared with the initial state,which can reach as much as 500ms.The practical value is certain.