Internet Fax Communications Research

Facsimile communication is a branch of still image communication, which has wide applications and fast development. The rapid development of the Internet and the low cost of IP communication, have made Facsimile over IP(FoIP) an inevitable trend.Combining IP technology and facsimile communication, FoIP fall into real-time FoIP and store-and-forward FoIP,which have respective advantages and shortcomings under different circumstances. Real-time FoIP is more attractive to users because of its short transmission delay and its traditional opteration mode. So it has better prospect. Up to now, there are far mature real-time FoIP technologies and products. Real-time FoIP is an advanced project and also has wide application.The paper focuses on real-time FoIP communication on the Internet .The facsimile gateway is key equipment of FoIP communication, so it is an important component of the project. The author regards the design of the gateway in real-time FoIP experimental system as the clue, and does research on the protocols concerning to real-time FoIP and their implementation. Including mainly: the functional architecture designs of the real-time FoIP gateway; the research and implementation of communication procedures based on the recommendation T.30 between the facsimile terminal and the gateway; the research and implementation of communication procedures based on the recommendation T.38 between gateways and the design of practical, concrete frame structure of IFP and UDPTL packets; The research and implementation of call establishment procedures between gateways. In course of implementation of the real-time FoIP experimental system, involved the research and application of serial communication technology , MODEM communication technology -. network programming technology and multithreading programming technology, etc. On the basis of this, according to Object Oriented idea, The author have programmed high-efficiency facsimile communication class and network facsimile communication class with event-driven mechanisms. overlapped I/O operation and multithreading programming technology. At last, this paper analyses the transmission delay of real-time FoIP,...