Research And Implementation On PPP Header Compression And Decompression Algorithm

PPP is one of the most widely used data link protocols in network communication. PPP header compression protocol is a standard which compresses redundant information in PPP header. The thesis discusses and implements the PPP header compression and decompression algorithm.First, by analyzing the encapsulation mode of PPP and the negotiation process of LCP and NCP, combined with the encapsulation format of LCP and NCP data package and their switching processes, LCP and NCP negotiation process is classified in detail.Second, Multilink PPP and PPP header compression protocol are analyzed. Then, the thesis analyzes PPP's frame structure, negotiation process and working theory, and mainly analyzes several PPP header compression protocols, such as Full Header, Compressed_TCP, Compressed_RTP and Compressed_Non_TCP.Third, the fundamental principle of PPP header compression and decompression is analyzed, and the algorithm that reconstructs PPP multilink data is raised. Based on that, a common decompression algorithm available for all kinds of PPP header compression signals is designed. Through data processing practice, the multilink reconstruction strategy and header compression decompression algorithm are verified.Finally, through the above analysis and research, the thesis designs and implements a universal decompression process platform which is applicable for all types of compression data we found. The platform is a real time process system which works well in actual task and is reliable for a long time.