Analysis And Application For The JXTA Protocols Of P2P

With the rapid development and popularization of Internet, P2P becomes a hot spot in the computer network technology. Compared with the traditional C/S pattern, it has lots of incomparable superiorities, such as:non-centralization, expansibility, robustness, high cost performance and load balancing. It makes the application core of network proliferate from the central server to the network edge terminal device. Being a very good supplement of C/S pattern,it has been applied unceasingly to file sharing, coordinated computation, information search, electronic commerce and network game etc. But the multitudinous P2P systems do their own way in their own field, they has formed a lot of isolated P2P island.This departed from the original P2P design intention--distributionalshare. Because of its characteristics such as interoperability, platform independence and ubiquity, JXTA becomes the ideal bridge to link these islands.This paper does research on JXTA protocols, aiming to build efficient, expansible and interoperable P2P application.Firstly, the thesis briefly introduces concepts and characteristics of P2P and compares three kinds of P2P models. By analyzing the shortcomings of existing P2P application, it introduces the JXTA platform;Secondly, it shows the construction layer, essential factor and protocol stack of JXTA and makes some thorough discussions of JXTAprotocols--PDP and PBP by instance. Based on this, a virtual classroomexamination prototype system is implemented and tested, to validate its feasibility and correctness;Finally, it discusses the key technology of JXTA. The JXTA discovery mechanism combines many discovery ways, with good performance in whole, but it also has the disadvantages on DHT Algorithm of SRDI, the response time of search, discovery way in subnet and superpeer mechanism. Traversing firewall and NAT are also raised in this paper. It compares exsisting P2P traversing technologies, expatiates traversing way of JXTA, and points out it combines relaying and connection reversal.The research of this paper provides useful information for developing efficient resources discovery mechanism in the future and also advances the research on P2P based on JXTA.