Design&realization Of Fax Over IP In Voice Gateway

With the rapid development of Internet, more and more services are provided in IP network, Fax over IP(FoIP) is one of the applications, it merges the legacy communication technic and IP technic. Currently, the Fax is delivered in PSTN network, it is still belong to data communication over telephone network. This method has some disadvantages, such as higher charge rate, less capability, lower efficiency. Otherwise, Fax over IP has many advantages, such as real time, similar operation with legacy Fax, low charge rate. It is very useful technique. Because the interface is very complex and so many parameters are included, it should be debugged many times to make sure it works well. This kind of effort makes it hard to design and practice.This thesis provides a solution about how to practice Fax over IP in Gateway, a kind of network commutations equipment. Analyzes Procedures fo Document Facsimile Transmission in the General Switched Telephone Network (T.30); Procedures for Real-Time Group 3 Facsimile Communication over IP Networks(T.38);Process of FoIP setup based on H.323 protocol. Then based on above items, it provides the architecture and solution of fax over IP. According to application of practical application, it analyzes how DSP support IP Fax, divides FoIP solution into several modules, and introduces the design and how to realize.According to the test result, If Fax over IP is used, it is more efficient to network resource. The charge rate is much lower. It extends the capability of voice interface card in voice gateway. It makes our product more competitive in market.There are so complex interfaces, so broad basic knowledge and so many parameters related with fax over IP.The author only focuses on how to design and practice Fax over IP in FXS voice interface board. The successive research work will focus on some related characters, security feature and Fax over SIP protocol.