Assuring virtual network reliability and resilience

A framework developed that uses reliability block diagrams and continuous-time Markov chains to model and analyse the reliability and availability of a Virtual Network Environment (VNE). In addition, to minimize the unpredicted failures and reduce the impact of failure on a virtual network, a dynamic solution proposed for detecting a failure before it occurs in the VNE. Moreover, to predict failure and establish a tolerable maintenance plan before failure occurs in the VNE, a failure prediction method for VNE can be used to minimise the unpredicted failures, reduce backup redundancy and maximise system performance.

Entropy-based collaborative detection of DDOS attacks on community networks

A community network often operates with the same Internet service provider domain or the virtual network of different entities who are cooperating with each other. In such a federated network environment, routers can work closely to raise early warning of DDoS attacks to void catastrophic damages. However, the attackers simulate the normal network behaviors, e.g. pumping the attack packages as poisson distribution, to disable detection algorithms. It is an open question: how to discriminate DDoS attacks from surge legitimate accessing. We noticed that the attackers use the same mathematical functions to control the speed of attack package pumping to the victim. Based on this observation, the different attack flows of a DDoS attack share the same regularities, which is different from the real surging accessing in a short time period. We apply information theory parameter, entropy rate, to discriminate the DDoS attack from the surge legitimate accessing. We proved the effectiveness of our method in theory, and the simulations are the work in the near future. We also point out the future directions that worth to explore in the future.

Multi-level virtual ring : a foundation network architecture to support peer-to-peer application in wireless sensor network

Two main problems prevent the deployment of peer-to-peer application in a wireless sensor network: the index table, which should be distributed stored rather than uses a central server as the director; the unique node identifier, which cannot use the global addresses. This paper presents a multi-level virtual ring (MVR) structure to solve these two problems.

The index table in MVR is distributed stored by using the DHT technique. MVR is constructed decentralized and runs on mobile nodes themselves, requiring no central server or interruption. Naming system in MVR uses natural names rather than global addresses to identify sensor nodes. The MVR can route directly on the name identifiers of the sensor nodes without being aware the location. Some sensor nodes are selected as the backbone nodes by the backbone selection algorithm and are placed on the different levels of the virtual rings. MVR hashes nodes’ identifiers on the virtual ring, and stores them at the backbone nodes. Furthermore, MVR adopts cross-level routing to improve the routing efficiency.

Experiments using ns2 simulator for up to 200 nodes show that the storage and bandwidth requirements of MVR grow slowly with the size of the network. Furthermore, MVR has demonstrated as self-administrating, fault-tolerant, and resilient under the different workloads.

Multi-level virtual ring : cross-level name routing with embedded identifier in sensor network

This paper presents the Multi-level Virtual Ring (MVR), a new name routing scheme for sensor networks. MVR uses selection algorithm to identify sensor nodes' virtual level and uses Distribution Hash Table (DHT) to map them to the MVR, The address routing performs well in wired network, but it's not true in sensor network. Because when nodes are moving, the address of the nodes must be changed Further, the address routing needs servers to allocate addresses to nodes. To solve this problem, the name routing is being introduced, such as Virtual Ring Routing (VRR). MVR is a new name routing scheme, which improves the routing performance significantly by introducing the multi-level virtual ring and cross-level routing. Experiments show this embedded name routing is workable and achieves better routing performance.

Virtual backbone content routing in wireless ad-hoc network

We developed a new content routing based on the virtual backbone structure, which groups wireless nodes and contents into a virtual architecture. Our approach is scalable, works with local information, and does not rely on address information. The naming system uses flat naming to identify nodes and contents, and organizes these identifiers together. Backbone nodes can be selected automatically or predefined to direct their associated normal nodes in a local area. The normal nodes are guided by the backbone nodes to full fill the searching and routing processes. With a virtual structure, the searching performance can be improved by using the DHT technique.

Experiments using ns2 simulator demonstrate that this virtual backbone routing architecture has the following significances: workable without being aware address in a mobile situation; scalable with the size of network; efficient in terms of the reduced hop counts and short end-to-end delay, and also resistant to the dead-end problem.

The social network virtual design studio : integrated design learning using blended learning environments

Online communications, multimedia, mobile computing and face-to-face learning create blended learning environments to which some Virtual Design Studios (VDS) have reacted to. Social Networks (SN), as instruments for communication, have provided a potentially fruitful operative base for VDS. These technologies transfer communication, leadership, democratic interaction, teamwork, social engagement and responsibility away from the design tutors to the participants. The implementation of Social Network VDS (SNVDS) moved the VDS beyond its conventional realm and enabled students to develop architectural design that is embedded into a community of learners and expertise both online and offline. Problem-based learning (PBL) becomes an iterative and reflexive process facilitating deep learning. The paper discusses details of the SNVDS, its pedagogical implications to PBL, and presents how the SNVDS is successful in enabling architectural students to collaborate and communicate design proposals that integrate a variety of skills, deep learning, knowledge and construction with a rich learning experience.

Multi-level virtual ring : an architecture for content routing in wireless sensor network

Two main problems prevent the deployment of content delivery in a wireless sensor network: the address, which is widely used in the Internet as the identifier, is meaningless in wireless network, and the routing efficiency is a big concern in wireless sensor network. This paper presents an embedded multi-level ring (MVR) structure to address those two problems. The MVR uses names rather than addresses to identify sensor nodes. The MVR routes packets on the name identifiers without being aware the location. Some sensor nodes are selected as the backbone nodes and are placed on the different levels of the virtual rings. MVR hashes nodes and contents identifiers, and stores them at the backbone nodes. MVR takes the cross-level routing to improve the routing efficiency. Further, MVR is constructed decentralized and runs on the mobile nodes themselves, requiring no central control. Experiments using ns2 simulator for up to 200 nodes show that the storage and bandwidth requirements of MVR grow slowly with the size of the network. Furthermore, MVR has demonstrated as self-administrating, fault-tolerant, and resilient under the different workloads. We also discuss alternative implementation options, and future work.

Virtual design studio within a blended social network

Online interactions, multimedia, mobile computing and face-to-face learning create blended learning environments to which some Virtual Design Studios (VDS) have reacted. Social Networks (SN), as instruments for communication, have provided a potentially fruitful operative base for VDS. These technologies transfer communication, leadership, democratic interaction, teamwork, social engagement and responsibility away from the design tutors to the participants. The implementation of a Social Network VDS (SNVDS) moved the VDS beyond its conventional realm and enabled students to develop architectural design that is embedded into a community of learners and their expertise both online and offline. Problem-based learning (PBL) becomes an iterative and reflexive process facilitating deep learning. The paper discusses details of the SNVDS, its pedagogical implications to PBL, and presents how the SNVDS is successful in empowering architectural students to collaborate and communicate design proposals that integrate a variety of skills, deep learning, knowledge and construction with a rich learning experience.

A virtual clinic : telemetric assessment and monitoring for rural and remote areas

This article reports the establishment of a pilot ‘virtual clinic’ in a rural region of Victoria, Australia. Using low-cost videophones that work across ordinary phone lines, together with off-the-shelf (mostly automatic) clinical tools, local volunteers have been trained to mediate a virtual consultation between simulated patients and local GPs. This system has the potential to save long trips into town by such patients since the traditional ‘home visit’ is not feasible, as well as to provide regular home monitoring for those with chronic conditions. This in turn should impact favourably on ambulance deployment, sometimes enabling patients to avoid going to hospital or allowing them to come home sooner than otherwise would be the case, and generally to offer a sense of medical security to those living in isolated regions.

Information navigation and knowledge discovery in virtual communities

Over the past decade, advances in the Internet and media technology have literally brought people closer than ever before. It is interesting to note that traditional sociological definitions of a community have been outmoded, for community has extended far beyond the geographical boundaries that were held by traditional definitions (Wellman & Gulia, 1999). Virtual or online community was defined in such a context to describe various forms of computer-mediated communication (CMC). Although virtual communities do not necessarily arise from the Internet, the overwhelming popularity of the Internet is one of the main reasons that virtual communities receive so much attention (Rheingold, 1999). The beginning of virtual communities is attributed to scientists who exchanged information and cooperatively conduct research during the 1970s. There are four needs of participants in a virtual community: member interest, social interaction, imagination, and transaction (Hagel & Armstrong, 1997). The first two focus more on the information exchange and knowledge discovery; the imagination is for entertainment; and the transaction is for commerce strategy. In this article, we investigate the function of information exchange and knowledge discovery in virtual communities. There are two important inherent properties embedded in virtual communities (Wellman, 2001):

Piggyback hunting-browsing the internet in Australia via unsecured wireless networks : virtual theft or acceptable behaviour in an online world?

In a world that is increasingly dominated by the Internet, there is a growing demand for low cost access at the users convenience. The expansion of wireless Internet networks, in particular unsecured wireless Internet networks, gives rise to novel challenges for the regulation of Internet access. The ability to access unsecured wireless Internet networks with ease and with very little impact upon the owner of the network suggests that such 'piggybacking' may be criminal behaviour or may amount to an actionable civil wrong. This paper will explore the legal ramifications of piggybacking an unsecured wireless network with knowledge that there is no entitlement to the use of the network and will consider what Australian authorities should do about this situation. This paper will look at the position in Australia and juxtapose this with that of the United Kingdom and the United States of America. In both the United Kingdom and the United States of America prosecutions have taken place of individuals who knowingly accessed unsecured wireless
networks for their own personal use.

The development of a generic framework for the implementation of a cheap, component-based virtual video-conferencing system

We address the problem of virtual-videoconferencing. The proposed solution is effected in terms of a generic framework based on an in-house Virtual Reality system. The framework is composed of a number of distinct components: model acquisition, head tracking, expression analysis, network transmission and avatar reconstruction. The framework promises to provide a unique, cheap, and fast system for avatar construction, transmission and animation. This approach affords a conversion from the traditional video stream approach to the management of an avatar remotely and consequently makes minimal demands on network resources.