764 research outputs found

    Service management for multi-domain Active Networks

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    The Internet is an example of a multi-agent system. In our context, an agent is synonymous with network operators, Internet service providers (ISPs) and content providers. ISPs mutually interact for connectivity's sake, but the fact remains that two peering agents are inevitably self-interested. Egoistic behaviour manifests itself in two ways. Firstly, the ISPs are able to act in an environment where different ISPs would have different spheres of influence, in the sense that they will have control and management responsibilities over different parts of the environment. On the other hand, contention occurs when an ISP intends to sell resources to another, which gives rise to at least two of its customers sharing (hence contending for) a common transport medium. The multi-agent interaction was analysed by simulating a game theoretic approach and the alignment of dominant strategies adopted by agents with evolving traits were abstracted. In particular, the contention for network resources is arbitrated such that a self-policing environment may emerge from a congested bottleneck. Over the past 5 years, larger ISPs have simply peddled as fast as they could to meet the growing demand for bandwidth by throwing bandwidth at congestion problems. Today, the dire financial positions of Worldcom and Global Crossing illustrate, to a certain degree, the fallacies of over-provisioning network resources. The proposed framework in this thesis enables subscribers of an ISP to monitor and police each other's traffic in order to establish a well-behaved norm in utilising limited resources. This framework can be expanded to other inter-domain bottlenecks within the Internet. One of the main objectives of this thesis is also to investigate the impact on multi-domain service management in the future Internet, where active nodes could potentially be located amongst traditional passive routers. The advent of Active Networking technology necessitates node-level computational resource allocations, in addition to prevailing resource reservation approaches for communication bandwidth. Our motivation is to ensure that a service negotiation protocol takes account of these resources so that the response to a specific service deployment request from the end-user is consistent and predictable. To promote the acceleration of service deployment by means of Active Networking technology, a pricing model is also evaluated for computational resources (e.g., CPU time and memory). Previous work in these areas of research only concentrate on bandwidth (i.e., communication) - related resources. Our pricing approach takes account of both guaranteed and best-effort service by adapting the arbitrage theorem from financial theory. The central tenet for our approach is to synthesise insights from different disciplines to address problems in data networks. The greater parts of research experience have been obtained during direct and indirect participation in the 1ST-10561 project known as FAIN (Future Active IP Networks) and ACTS-AC338 project called MIAMI (Mobile Intelligent Agent for Managing the Information Infrastructure). The Inter-domain Manager (IDM) component was integrated as an integral part of the FAIN policy-based network management systems (PBNM). Its monitoring component (developed during the MIAMI project) learns about routing changes that occur within a domain so that the management system and the managed nodes have the same topological view of the network. This enabled our reservation mechanism to reserve resources along the existing route set up by whichever underlying routing protocol is in place

    A Flexible IP Active Networks Architecture

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    Education Licensure Candidates During the Time of COVID-19: University Supervisors’ Reflections About the Forgotten Few

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    Education at K–12 through university levels has faced extraordinary upheaval in the time of COVID-19. As universities and K–12 school systems struggled independently to adapt to rapidly changing demands, teacher and administrator licensure candidates were confronted with unprecedented challenges in both worlds simultaneously. The licensure candidates were the forgotten few, stuck between higher education and K–12 education, while struggling to keep up with the demands of their personal lives and professional futures. With limited guidance from their universities and school systems, licensure candidates turned to their university field placement supervisors for direction. In response, supervisors became adaptive leaders and flexible problem solvers with compassionate hearts focused on supporting candidates’ success against all odds. Through the reflections of university supervisors, this scholarly essay provides a window into the unique experiences of education licensure candidates and their university supervisors as they navigate the worlds of higher education and K–12 education

    Security Protocol for Active Networks.

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    Automating embedded analysis capabilities and managing software complexity in multiphysics simulation part I: template-based generic programming

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    An approach for incorporating embedded simulation and analysis capabilities in complex simulation codes through template-based generic programming is presented. This approach relies on templating and operator overloading within the C++ language to transform a given calculation into one that can compute a variety of additional quantities that are necessary for many state-of-the-art simulation and analysis algorithms. An approach for incorporating these ideas into complex simulation codes through general graph-based assembly is also presented. These ideas have been implemented within a set of packages in the Trilinos framework and are demonstrated on a simple problem from chemical engineering

    Network architecture for large-scale distributed virtual environments

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    Distributed Virtual Environments (DVEs) provide 3D graphical computer generated environments with stereo sound, supporting real-time collaboration between potentially large numbers of users distributed around the world. Early DVEs has been used over local area networks (LANs). Recently with the Internet's development into the most common embedding for DVEs these distributed applications have been moved towards an exploiting IP networks. This has brought the scalability challenges into the DVEs evolution. The network bandwidth resource is the more limited resource of the DVE system and to improve the DVE's scalability it is necessary to manage carefully this resource. To achieve the saving in the network bandwidth the different types of the network traffic that is produced by the DVEs have to be considered. DVE applications demand· exchange of the data that forms different types of traffic such as a computer data type, video and audio, and a 3D data type to keep the consistency of the application's state. The problem is that the meeting of the QoS requirements of both control and continuous media traffic already have been covered by the existing research. But QoS for transfer of the 3D information has not really been considered. The 3D DVE geometry traffic is very bursty in nature and places a high demands on the network for short intervals of time due to the quite large size of the 3D models and the DVE application requirements to transmit a 3D data as quick as possible. The main motivation in carrying out the work presented in this thesis is to find a solution to improve the scalability of the DVE applications by a consideration the QoS requirements of the 3D DVE geometrical data type. In this work we are investigating the possibility to decrease the network bandwidth utilization by the 3D DVE traffic using the level of detail (LOD) concept and the active networking approach. The background work of the thesis surveys the DVE applications and the scalability requirements of the DVE systems. It also discusses the active networks and multiresolution representation and progressive transmission of the 3D data. The new active networking approach to the transmission of the 3D geometry data within the DVE systems is proposed in this thesis. This approach enhances the currently applied peer-to-peer DVE architecture by adding to the peer-to-peer multicast neny_ork layer filtering of the 3D flows an application level filtering on the active intermediate nodes. The active router keeps the application level information about the placements of users. This information is used by active routers to prune more detailed 3D data flows (higher LODs) in the multicast tree arches that are linked to the distance DVE participants. The exploration of possible benefits of exploiting the proposed active approach through the comparison with the non-active approach is carried out using the simulation­based performance modelling approach. Complex interactions between participants in DVE application and a large number of analyzed variables indicate that flexible simulation is more appropriate than mathematical modelling. To build a test bed will not be feasible. Results from the evaluation demonstrate that the proposed active approach shows potential benefits to the improvement of the DVE's scalability but the degree of improvement depends on the users' movement pattern. Therefore, other active networking methods to support the 3D DVE geometry transmission may also be required

    Efficient security management for active networks.

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    Due to the dynamic nature and dynamic routing capability of active packets, security in active networks should be hop-by-hop based. This thesis discusses the identified drawbacks of existing approaches. These drawbacks are: the high performance overhead generated by per-hop Security Association (SA) negotiation prior to secured active packet transmission the high complexity in SA negotiation handshake process active packet can only be securely transmitted after SA negotiations the shared key set generated for protecting active packets may not have Perfect Forward Secrecy (PFS) lack of confidentiality protection on exchanged symmetric keys and active packets lack of SA negotiation power and scalability issues. This thesis presents a novel hop-by-hop active network security management approach known as Security Protocol for Active Networks (SPAN). SPAN is designed to enable secure active packet transmission during a series of hop-by-hop SPAN SA negotiation along a new execution path, instead of after. The design of SPAN has taken into consideration the factors of security, efficiency, flexibility, scalability, and applicability. SPAN is resistant to replay, man-in-the-middle, impersonate attacks. SPAN is designed to detect DoS attacks much more efficiently. Furthermore, SPAN is uniquely designed to enhance the robustness and efficiency of underlying active networking systems
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