The Design And Implementation Of Real-time Foip Based On PJSIP

With the development of the Internet, the traditional telecommunication servicesare being replaced by IP multimedia services. The network-based business influencespeople’s modern lives significantly. With the fusion with traditionaltelecommunication services and IP technology, FOIP (Fax over IP) attracts broadinterest and develops rapidly.FOIP, which allows to transmit traditional PSTN fax via the Internet, is graduallygetting popular because of the low cost associated with the Internet. This projectdeveloped and implemented the FOIP based on embedded platform and PJSIPprotocol by combining embedded technology with sip.This paper describes the history of facsimile technology and discusses in detailthe facsimile technology together with related protocols, such as T.30，T.38,SIP，SDPprotocol etc, emphasizing the technology and implementation regarding the T.38protocol of network facsimile. Based on this, a FOIP scheme is proposed. The maingoals of this project include:1. Analyze the design and implementation methodology of PJSIP by usingPJSIP protocol stack as the communication signaling protocol of FOIP networkfacsimile. Propose a scheme for real time network facsimile terminals based on thePJSIP protocol stack. Describe in detail the system architecture, hardware design andsoftware design.2. This project accomplished the embedded Linux system platform, which is based on AT91SAM9263, and use the Redboot underlying bootstrap program. Basedon this, a software design scheme which is based on embedded Linux is proposed.Describe PJSIP and porting Spandsp. Detailed description of SIP signaling controllermanagement and T.38communication module.3. Implement the transmission of binary files in the environment of networkfacsimile using PJSIP and T.434protocol. And describe in detail BFT coding anddecoding process. To establish the foundation for expanding network facsimile usageby transmission of binary files.4. Design the human-machine interface of the network facsimile usinguCGUI as the development kit for graphical user interfaces. Describe in detail thescheme of human-machine interface and communication protocol. accomplished thehuman-machine interface to the platform based on LPC2468hardware.The evaluation of this scheme shows that the proposed network facsimilescheme satisfies the design requirements. Currently, this real time network facsimilescheme has been applied in real products. The research and practice show that thisscheme has superior quality and is suitable for certain branches and fields.