Research On Key Techniques Of Network Aware Peer-to-Peer Overlay Network

Recently, peer-to-peer network applications play an important role in todays Internet. While the peer-to-peer technologies are widely used, the peer-to-peer applications occupied a large part of the Internet traffics according to the statistics. After further researching, it was found that one of the reason that caused those traffics is the non-optimization of the routing in peer-to-peer network. And this is because of that the overlay network is not match to the physical network underneath. That is to say the overlay network is not network-aware. This dissertation focused on some of the key technologies that make the peer-to-peer overlay network network-aware. Main contributions and creative points of this dissertation are as following.1. Considering the fact that there is an high relative error in computing the distance to near peers in Vivaldi while the average relative error remains low, a repaired Vivaldi is proposed. In the repaired Vivaldi, the relative error in computing the distance to near peers is decreased. The experiments show that the ability of choosing the nearest peer among neighbors is also improved in repaired Vivaldi with only little expense in the average relative error and relative rank loss rate. The reason why we dig into network coordinates system firstly is that most of the algorithms in this dissertation were make use of the network coordinates system. With the help of network coordinates system, any peer can aware of its relative position in Internet and can estimate the network latency to the other peer without probing.2. A new particle swarm based network nodes clustering algorithm is proposed in this dissertation. One of the difficulties of clustering the network nodes is how to cluster them distributively. The particle swarm algorithm solve the problem easily as the particles in network space exploring and exploiting the space independently. While particles flying they communicate and exchange the best fitness they found. So the particle swarm can find a better fitness quickly. The proposed algorithm is based on the facts that the network clustering algorithm is a algorithm that each node find a better cluster they belong to. So applying the particle swarm algorithm in network node clustering problem, we can cluster the network distributively.3. For structured peer-to-peer network overlay, reorganize the well organized nodes into a network-aware overlay is too difficult. In this dissertation, we propose a dual direction routing algorithm for Chord and a network proximity aware routing table protocol for more optimal routing. The dual direction routing algorithm for Chord can route the message in clockwise direction and counter clockwise direction too. Thus the average path length reduced to half of the original. Additionally, due to each of the step can be chosen from two candidate nodes, the expected forward latency reduced too. This paper also investigates the proximity routing table construction in a XOR metric based overlay network. In this overlay network, Nodes in the overlay network can be viewed as leafs, items in a routing table can be viewed as the pointers to the trees non-overlapped. So the routing table entries can be pointed to any node in the corresponding tree. Thus there are more candidate for the entry. The routing table entry can be optimized by choose one of the nearest node.