A Study About MP2P Based On Kademiia

Along with development of the wireless communication technology andimprovement of the wireless terminal technology, mobile Internet technology hasdeveloped rapidly. Peer to Peer is a self-organizing, scalable, fault-tolerant,robust,distributed network, in the past decade, The P2P technology has made substantialcontribution to the rapid growth and popularization of Internet. it has stimulated thedevelopment of broadband Multimedia service and so on, and improved theparticipation of the users on the Internet. If the P2P technology is applied to mobileInternet,i.e. building a mobile P2P network,this will improve greatly the developmentof mobile Internet and enthusiasm of users to participate in Internet.This paper willfirst discuss the characteristics of the mobile environment,and then solve the relatedquestions to construct a P2P network in a mobile environment.The structured P2P overlays based on distributed hash tables (DHTs) solve thescalability problem of unstructured P2P，and guarantee the efficiency of query，sothey develop rapidly and have a broad range of applications.Such as Kademlia,whichhas been used in eMule and BitComet network,has a good performance and has beenwidely used in search engines, resource sharing and distributed storage.in the sametime, it has the potenty to be applied in the mobile environment for it’s goodfault-tolerant performance.The P2P network in mobile environment is characterized by frequent changes innetwork topology,more serious topological inconsistency，the mobile node’s ownresource-constrained, larger latency,poor security. Among these issues, the problemsof frequent changes of the topology and more serious topological inconsistency aremost critical in an environment with highly dynamic participants,which is calledchurn.In this paper,the Kademlia protocol is applied to build a P2P network in themobile environment. The focus of this article is to address the routing performanceand topology inconsistencies of MP2P under strong churn. The main contents of thispaper include:1.The general schemes to deal with churn in the P2P network are researched atfirst to find a appropriate solution that can be used to overcome the churn. Thescheme of recursive routing with an acknowledgement mechanism is found suitablefor strong churn, and it can both provide a low bandwidth and low latency and avoid effectively the network connectivity problems which are caused by NAT or firewall.2.The paper introduces the common methods to solve the problem of topologicalinconsistency，and finds that the proximity routing scheme which is based on thelatency and the prefix metric of the nodeID is fit for kademlia to solve the problem oftopological inconsistency under strong churn， which can further enhance theperformance of the system.3.In this paper, a adaptation for Kademlia protocol is provided to fit for mobileenvironment. The scheme utilizes recursive overlay routing instead of iterativelookups of keys, and an intermediate node will send an message containing theaddresses of the next hop to the originator. In case of failure, the originator canreinitiate another lookup according to the address in the latest message. In order tosolve the problem of inconsistency of the logical network and physical network, theRTT of physical network is applied to reorder the next hop of the logical layer, and theentries that are closest to the destination node in the logical layer and physical layerare selected as the next hop, the routing performance is further improved.4.This paper studies the characteristics of the user behavior of the Kad networkand the mobile environment, the simulation environment settings are determined. andin the end，the key parameters of the Kademlia adaptation is evaluated in the overlayframework OverSim,and the results are presented and discussed.This paper presents the Kademlia optimization, which is effective to the churnproblem in a mobile environment, at the same time,to the real network connectionproblems caused by NAT or firewall; the proximity routing scheme which is based onthe latency and the prefix metric of the nodeID can solve partially the problem oftopology inconsistencies and gives further enhance the performance of the system.andit has a certain practical significance.