The Real Time Retrieval And Filtering System In The High-speed Networks

Internet has not only quickened the rate and broadened the route of information propagation, but also improved the economy, society and technology. With the rapid development of Internet and informatization, information security has become more and more significant. Besides security of information system, security of information content is also of great importance.The core of information retrieval is text information retrieval. Information filtering implies that identifying information on the network according to the character descriptions of information, and picking out pages which satisfy these characteristics. The progress of computer technology and the increment of information has made higher requirement, especially the appearance of network and multimedia technology have also urged the information retrieval and filtering. The latest trend of information retrieval and filtering technology should be intelligentized and personal.The traditional information retrieval and filtering approaches are implemented mostly by software. However, for real time receiving and processing signal in the gigabit network, we can't archive it only with software. The purpose of this thesis is designing the real time retrieval and filtering system in the high-speed networks. This system employs Dragon's hardware platform FIDS1200. Based on Intel'snetwork processor IXP1200 and IDT's fast stream classifier PP1200, the platform can develop applications and implement real time retrieval and filtering of text information.The thesis introduces the structure of FIDS 1200 and the working principle of entire system, describes the appearance and development of network processor, and also summarizes the features of IXP1200 and PP1200.Based on these contents, the thesis describes how to implement the text information retrieval and filtering system. This real-time system was divided into interface and process module. The interface module can implement I/O of gigabit network and the process of physical and link layer. Relying on the users' configurations, the process module can retrieve and filter packets, and dispense these packets according to the port number, IP address, characteristic string or the combination of them. Moreover, the development of the system also involves the knowledge of embedded real time operation system (ERTOS) and micro-code.At last, we analyze a number of experimental results and draw the following conclusion: the system follows the requirement of modular design, and users can configure it; because of applying the network processor and fast stream classifier, this system can implement real-time receiving and sending of gigabit network, text information retrieval and filtering.