7,935 research outputs found

    Multi-layer virtual transport network management

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    Nowadays there is an increasing need for a general paradigm which can simplify network management and further enable network innovations. Software Defined Networking (SDN) is an efficient way to make the network programmable and reduce management complexity, however it is plagued with limitations inherited from the legacy Internet (TCP/IP) architecture. In this paper, in response to limitations of current Software Defined Networking (SDN) management solutions, we propose a recursive approach to enterprise network management, where network management is done through managing various Virtual Transport Networks (VTNs) over different scopes (i.e., regions of operation). Different from the traditional virtual network model which mainly focuses on routing/tunneling, our VTN provides communication service with explicit Quality-of-Service (QoS) support for applications via transport flows, and it involves all mechanisms (e.g., addressing, routing, error and flow control, resource allocation) needed to support such transport flows. Based on this approach, we design and implement a management architecture, which recurses the same VTN-based management mechanism for enterprise network management. Our experimental results show that our management architecture achieves better performance.National Science Foundation awards: CNS-0963974 and CNS-1346688

    Frameworks for Protocol Implementation

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    This paper reports on the development of a catalogue of frameworks for protocol implementation. Frameworks are software structures developed for a specific application domain, which can be re-used in the implementation of various different concrete systems in this domain. By using frameworks we aim at increasing the effectiveness of the protocol implementation process. We assume that whenever protocols are directly implemented from their specifications one may be able to increase the correctness and the speed of the implementation process, and the maintainability of the resulting system. We argue that frameworks should match the concepts underlying the techniques used for specifying protocols. Consequently, we couple the development of frameworks for protocol implementation to the investigation of the different alternative design models for protocol specification. This paper presents the approach we have been using to develop frameworks, and illustrates this approach with an example of framework

    TINA as a virtual market place for telecommunication and information services: the VITAL experiment

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    The VITAL (Validation of Integrated Telecommunication Architectures for the Long-Term) project has defined, implemented and demonstrated an open distributed telecommunication architecture (ODTA) for deploying, managing and using a set of heterogeneous multimedia, multi-party, and mobility services. The architecture was based on the latest specifications released by TINA-C. The architecture was challenged in a set of trials by means of a heterogeneous set of applications. Some of the applications were developed within the project from scratch, while some others focused on integrating commercially available applications. The applications were selected in such a way as to assure full coverage of the architecture implementation and reflect a realistic use of it. The VITAL experience of refining and implementing TINA specifications and challenging the resulting platform by a heterogeneous set of services has proven the openness, flexibility and reusability of TINA. This paper describes the VITAL approach when choosing the different services and how they challenge and interact with the architecture, focusing especially on the service architecture and the Ret reference point definitions. The VITAL adjustments and enhancements to the TINA architecture are described. This paper contributes to proving that the TINA-based VITAL ODTA allows for easy and cost-effective development and deployment of advanced end-user and operator services, and can indeed act as the basis for a virtual market place for telecommunications service

    Service and device discovery of nodes in a wireless sensor network

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    Emerging wireless communication standards and more capable sensors and actuators have pushed further development of wireless sensor networks. Deploying a large number of sensor\ud nodes requires a high-level framework enabling the devices to present themselves and the resources they hold. The device and the resources can be described as services, and in this paper, we review a number of well-known service discovery protocols. Bonjour stands out with its auto-configuration, distributed architecture, and sharing of resources. We also present a lightweight implementation in order to demonstrate that an emerging standards-based device and service discovery protocol can actually be deployed on small wireless sensor nodes

    Using the Java Media Framework to build Adaptive Groupware Applications

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    Realtime audio and video conferencing has not yet been satisfactorily integrated into web-based groupware environments. Conferencing tools are at best only loosely linked to other parts of a shared working environment, and this is in part due to their implications for resource allocation and management. The Java Media Framework offers a promising means of redressing this situation. This paper describes an architecture for integrating the management of video and audio conferences into the resource allocation mechanism of an existing web-based groupware framework. The issue of adaptation is discussed and a means of initialising multimedia session parameters based on predicted QoS is described

    MENU: multicast emulation using netlets and unicast

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    High-end networking applications such as Internet TV and software distribution have generated a demand for multicast protocols as an integral part of the network. This will allow such applications to support data dissemination to large groups of users in a scalable and reliable manner. Existing IP multicast protocols lack these features and also require state storage in the core of the network which is costly to implement. In this paper, we present a new multicast protocol referred to as MENU. It realises a scalable and a reliable multicast protocol model by pushing the tree building complexity to the edges of the network, thereby eliminating processing and state storage in the core of the network. The MENU protocol builds multicast support in the network using mobile agent based active network services, Netlets, and unicast addresses. The multicast delivery tree in MENU is a two level hierarchical structure where users are partitioned into client communities based on geographical proximity. Each client community in the network is treated as a single virtual destination for traffic from the server. Netlet based services referred to as hot spot delegates (HSDs) are deployed by servers at "hot spots" close to each client community. They function as virtual traffic destinations for the traffic from the server and also act as virtual source nodes for all users in the community. The source node feeds data to these distributed HSDs which in turn forward data to all downstream users through a locally constructed traffic delivery tree. It is shown through simulations that the resulting system provides an efficient means to incrementally build a source customisable secured multicast protocol which is both scalable and reliable. Furthermore, results show that MENU employs minimal processing and reduced state information in networks when compared to existing IP multicast protocols

    Multicast broadcast services support in OFDMA-based WiMAX systems [Advances in mobile multimedia]

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    Multimedia stream service provided by broadband wireless networks has emerged as an important technology and has attracted much attention. An all-IP network architecture with reliable high-throughput air interface makes orthogonal frequency division multiplexing access (OFDMA)-based mobile worldwide interoperability for microwave access (mobile WiMAX) a viable technology for wireless multimedia services, such as voice over IP (VoIP), mobile TV, and so on. One of the main features in a WiMAX MAC layer is that it can provide'differentiated services among different traffic categories with individual QoS requirements. In this article, we first give an overview of the key aspects of WiMAX and describe multimedia broadcast multicast service (MBMS) architecture of the 3GPP. Then, we propose a multicast and broadcast service (MBS) architecture for WiMAX that is based on MBMS. Moreover, we enhance the MBS architecture for mobile WiMAX to overcome the shortcoming of limited video broadcast performance over the baseline MBS model. We also give examples to demonstrate that the proposed architecture can support better mobility and offer higher power efficiency
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