Java-based Telephony Software Design

Voice over IP is a rising technology which has a wide future in application. We can achieve the integration of data network and voice network by Voice over IP. It makes possible to communication anytime and anywhere of integrated information as well as saving various precious resources.JAVA is a widely-used network programming language. It is a new computational concept with two points. For one, as a programming language, it is simple, object oriented, no machine-relied, transplantable, secure, and it also provide a concurrency mechanism which results in high power, and get rid of much unreasonable content. For another, JAVA provides abundant class libraries, such as JAVA Sound API, which make programmers construct their systems conveniently.In P2P network, every computer on the network was an equal: Each computer could access the resources of any other computer on the network while making its own resources available. Communication among hosts was also equal: No computer was seen as a client or component of another, and all computers shared more-or-less equal bandwidth access to one another. P2P technologies adopt a network-based computing style that neither excludes nor inherently depends on centralized control points.The technology of NAT implements multiple access of network addresses, however, it hides inner network address information and host computers in different NAT areas could not identify each other for direct exchanging of information. As a result, P2P networks have to deal with the problem of NAT traversing.NAT can realize the multiplex network address and hide the information of internal network address. Host computers in different NAT areas could not identify each other for directly exchanging information. As a result, P2P network has to deal with the problem of NAT traversal. I have offered a solution of using a register server on internet and TCP protocol to implement the peer-to-peer information exchanging between two computers of different NAT areas in P2P network.JXTA is an open source platform for P2P applications which lets developers build and deploy P2P solutions more quickly. The objectives of JXTA Technology are good interoperability, platform independence and ubiquity.This software could implement real-time peer-to-peer voice communication by applying the technologies above synthetically. We can solve the problem of PC access in the internal LAN as well. In addition, the data encryption techniques provide a security of the voice transmission. The design of the software includes User Interface design and the implementation of real-time voice transmission. The User Interface integrates the function of IP address input, encryption option, voice sampling and the configuration of code parameters. And the implementation of lower voice data transmission is the core of the whole software, which involves voice input and output, voice sampling and playback, signal encoding and decoding, signal compressing and...