A Fast Joining Operation for Highly Dynamic Chord System |
Highly dynamic characteristic is one of the most important characteristics of P2P system in nature. Nodes may join in or leave the P2P system at any moment. Frequently joining or leaving must increase the maintenance overhead greatly in DHT system. To decrease the cost, we introduce a new join operation for Chord, named F-Join that is suitable for highly dynamic environments and can fast join in the system. F-Join builds finger table of node by the support of the fingers of the node's successor and predecessor. So, it decreases the lookup cost of building node's finger table and decreases the maintenance overheads finally. The theory and simulations show that F-Join can decrease the maintenance overheads greatly and improve the lookup performance. |
A Forwarding Model for Voronoi-based Overlay Network |
An approach to build highly scalable and robust networked virtual environments (NVEs) is using the peer-to-peer overlay networks. Voronoi-based Overlay Network (VON) has been proposed to maintain a highly overlay topology consistency in a bandwidth-efficient manner. However, the original proposal requires all nodes to connect directly with their relevant neighbors. This limits the number of neighbors should appear within the area of interest (AOI) of a given node. A new forwarding model for VON is proposed to solve this problem by connecting with only the nearest neighbors that is called the enclosing neighbors (EN), and propagate position updates information to other nodes by message forwarding. In this way, the AOI of a given node may be more flexibly expanded and different bandwidth capacities may be more efficiently utilized. |
A Peer-To-Peer Platform for Simulating Distributed Virtual Environments |
The current expansion of multi-player online games has
promoted the growth of large scale distributed virtual environments
(DVEs). In these systems, peer-to-peer architectures have been proved
as an efficient scheme for supporting massively multi-player
applications. In order to research on this type of architecture, it is
necessary to develop a distributed tool that allows to simulate
large-scale DVEs in an efficient way. In this paper, we propose a distributed platform for simulating Peer-To-Peer DVEs. This simulator is capable of providing the main performance metrics in distributed systems, and it contains all the elements involved in real DVE simulations like the awarenes method and the graphic interface. As a result, this tool can be used in real simulations of Peer-to-Peer DVEs, becoming an invaluable tool for capturing the behavior of this kind of systems. |
Secure random number agreement for peer-to-peer applications |
We propose a protocol for a group of peers in a peer-to-peer network to securely generate an agreed random value without the use of a central authority. We can vary the security parameters to maintain security (to a desired probability) in the presence of a high percentage of corrupt and colluding peers. We envision using this protocol to generate random content in a peer-to-peer game. It could also be used for generating input into peer-to-peer protocols that require random values, such as group selection. |
Scalable Networked Virtual Environments Using Unstructured Overlays |
Large-scale Networked Virtual Environments (NVEs) are used to
enable rich interactive experiences such as multiplayer games, military
and industrial training, and collaborative engineering systems. In
these applications, hosts must exchange data updates, in order to
maintain a consistent view of the virtual environment. In large-scale
environments, the volume of data places a heavy load on the networking
and computational resources available to each host. To improve
scalability, systems have employed a variety of techniques, including
data subscription, data segmentation, and multicast. In this paper, we describe a communication architecture for Networked Virtual Environments that takes advantage of unstructured peer-to-peer (P2P) overlay networks for message distribution. The overlay network design provides scalability while supporting easy deployment over today's Internet. The approach, when combined with data segmentation and data subscription, enables Internet deployment of large-scale NVEs. |
S/Kademlia: A Practicable Approach Towards Secure Key-Based Routing |
Security is a common problem in completely decentralized peer-to-peer systems. Although several suggestions exist on how to create a secure key-based routing protocol, a practicable approach is still unattended. In this paper we introduce a secure key-based routing protocol based on Kademlia that has a high resilience against common attacks by using parallel lookups over multiple disjoint paths, limiting free nodeId generation with crypto puzzles and introducing a reliable sibling broadcast. The latter is needed to store data in a safe replicated way. We evaluate the security of our proposed extensions to the Kademlia protocol analytically and simulate the effects of multiple disjoint paths on lookup success under the influence of adversarial nodes. |
ECHoP2P: Emergency Call Handling over Peer-to-Peer Overlays |
The impact of the peer-to-peer paradigm increases both in research and in industry. Still, serious applications for P2P-based systems are rare. On the other hand, Emergency Call Handling (ECH) is (or will be) a mandatory function for VoIP services. In this paper we investigate international legal and technical requirements of ECH and present ECHoP2P, a solution that fulfills these requirements. Based on Globase.KOM and HiPNOS.KOM, ECHoP2P provides the functionality to determine the closest and (geographically) responsible Emergency Station to a calling peer. Further, Emergency Calls are processed with highest priority in the overlay, so that quality of service guarantees are given. We evaluated ECHoP2P thoroughly and present the quality and costs analysis, identified tradeoffs and effects of optimization parameters. ECHoP2P provides a fully evaluated solution for Emergency Call Handling and for further location-aware applications. |
A Clustering Model for Memory Resource Sharing in Large Scale Distributed System |
As an innovative application of large scale distributed network computing system, RAM Grid try to solve the problem of memory resource sharing and utilization. Due to the special properties of memory, traditional resource information management approaches can not be adapted easily. This paper proposes a clustering based resource aggregating scheme under the background of RAM Grid, which can reduce the scale of resource information management efficiently. With analogy to the force field and potential energy theory in physics, the basic model, force field-potential energy model and corresponding distributed algorithms are proposed respectively. The models and algorithms are also evaluated by real network topologies based simulation. |
Delay Sensitive Identity Protection in Peer-to-Peer Online Gaming Environments |
Peer-to-peer computing overcomes communication bottleneck problems associated with centralized game servers and provides an alternative mechanism to support massively multi-player online gaming (MMOG) applications. A potential security problem associated with this approach relates to player identity. In an MMOG, users from different parts of the network interact with each other in a virtual world. In a peer-to-peer model, these interactions happen directly between the peers and this leads to the IP addresses of peers being available in the network packets. Malicious users can extract the IP addresses of their opponents and the information can be used to gain unfair advantage by compromising their opponents' computers. The well known approach to this problem is the use of anonymizing networks (onion routing and mixing), that anonymize the sender and the destination IP addresses from the peers along a path. However this approach introduces significant delays which are not desirable in MMOG applications. This paper proposes the use of a secret shared key to reduce computational delay and also provides a theoretical framework for trading off the strength of anonymity for reduced delay with respect to classes of interactions in the MMOG. The results suggest that appropriately low delays can be achieved with small reductions in anonymity strength. |
Effect of Unstable Routing in Location-Aware Mobile Ad Hoc Networks on a Geographic DHT Protocol |
Geographic distributed hash table (DHT) protocols assume that the set of <key, value> pairs, called indexes, should be distributed among nodes. In geographic DHT protocols, the overhead of index redistribution due to node mobility may be high enough to impact the normal lookup operation if each node contains a large number of indexes. In our previous work, we proposed an efficient lookup protocol, called Double Indirect Access (DIA), that dispenses with index redistribution to improve lookup performance. We also evaluated the performance of DIA by using our own simulator which could show only limited simulation results with the assumptions that all nodes are connected and the packets are transferred instantly without delay. In this paper, we implement DIA into the packet-level simulator ns2 in order to evaluate how DIA is affected by the underlying unstable routing in MANET. The metrics of the effectiveness are considered lookup success rate and bandwidth consumption, and the simulation results show that DIA performs better than a conventional geographic DHT protocol. |
Directions for Peer-to-Peer Based Mobile Pervasive Augmented Reality Gaming |
Pervasive Augmented Reality Gaming and Mobile P2P are both attracting significant focus and much progress has occurred recently. Augmented reality games extend reality with virtual elements to enhance game experience and mobile P2P networks provide autonomous, self-organizing, scalable and robust communication platforms. We review the technological challenges in both mobile P2P computing and AR domains by investigating some existing related works. Then we propose possible directions of the mobile AR collaborative gaming over p2p networks and show its advantages over other AR gaming and discuss the feasibility and future requirements regarding the support for this type of game. |
P2P-based Geometric Computation Method for Extracting ROI from Ubiquitous Video Camera |
This paper proposes a method for extracting the ROI using geometric computations, to obtain information of commonly-interested objects by multiple users. The authors use P2P Delaunay Network to share the regional information shot by cameras, and extract the most intersecting area of camera ranges as ROI. In P2P Delaunay Network, nodes and edges refer to as computers and their connections. This proposed method can construct P2P Delaunay Network using locations of mobile devices as GPS phones or PDAs equipped with a camera, and process computations distributively with these devices. Thereby, a P2P Delaunay network can be constituted, without using the computer resource of other settlements. The method first partitions the plane and assigns the partitions to nodes according to their locations using P2P Delaunay Network. Then, each camera sends its camera range information to nodes, and each node thus processes computation distributively. The node which has received multiple camera range information computes the intersecting area within its partition. Finally, the ROI can be determined, by computing the most intersecting area among all nodes. The authors examine the proposed method by evaluating the frequency of region partitioning and data transfer for each node through numerical simulation. |
A Comparative Study on Peer-to-Peer Failure Rate Estimation |
The robustness of Peer-to-Peer systems is challenged by its highly dynamic nature. Frequent peer failure and departure events introduce uncertainty for which is considered exceptional in traditional distributed systems. The difficulty of monitoring such large scale networks is further exacerbated because it has to be done in a completely decentralized way for both scalability and reliability concerns. Some methods for estimating peer failure rate have been applied in Peer-to-Peer systems, however their comparative performance has not yet been reported in the literature. We simulate three different failure rate estimation methods and compare their accuracy and response time with respect to sample size, stabilization interval and neighbour set size. We conclude that the Maximum Likelihood Method introduced is better than the Failure Frequency based Methods commonly used in current Peer-to-Peer systems. |
Peer-to-Peer AOI Voice Chatting for Massively Multiplayer Online Games |
In recent years, massively multiplayer online games MMOGs) have become more and more popular. Many techniques have been proposed to enhance the experience of using MMOGs, such as realistic graphics, vivid animations, and player communication tools, etc. However, in most MMOGs, communication between players is still based on text, which is unnatural and inconvenient. In this paper, we propose the concept of AOI voice chatting for MMOGs. The term AOI stands for the area of interest; a player in the MMOG only pays attention to his/her AOI. By AOI voice chatting, a player can easily chat by voice with other plays in the AOI. This improves the way players communicate with one another and provides a more realistic virtual environment. We also propose two peer-to-peer schemes, namely QuadCast and SectorCast, to achieve efficient AOI voice chatting for MMOGs. We perform simulation experiments to show that the proposed schemes have reasonable end-to-end delay and affordable bandwidth consumption. |
2007 International Workshop on Peer-to-Peer Networked Virtual Environments
(P2P-NVE 2007)
Last modified at 2007/11/08