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Large-scale Virtualization in the Emulab Network Testbed
"... Network emulation is valuable largely because of its ability to study applications running on real hosts and “somewhat real ” networks. However, conservatively allocating a physical host or network link for each corresponding virtual entity is costly and limits scale. We present a system that can fa ..."
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Cited by 33 (3 self)
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Network emulation is valuable largely because of its ability to study applications running on real hosts and “somewhat real ” networks. However, conservatively allocating a physical host or network link for each corresponding virtual entity is costly and limits scale. We present a system that can faithfully emulate, on low-end PCs, virtual topologies over an order of magnitude larger than the physical hardware, when running typical classes of distributed applications that have modest resource requirements. This version of Emulab virtualizes hosts, routers, and networks, while retaining near-total application transparency, good performance fidelity, responsiveness suitable for interactive use, high system throughput, and efficient use of resources. Our key design techniques are to use the minimum degree of virtualization that provides transparency to applications, to exploit the hierarchy found in real computer networks, to perform optimistic automated resource allocation, and to use feedback to adaptively allocate resources. The entire system is highly automated, making it easy to use even when scaling to more than a thousand virtual nodes. This paper identifies the many problems posed in building a practical system, and describes the system’s motivation, design, and preliminary evaluation. 1
Virtualization Techniques in Network Emulation Systems
"... Abstract. The continuous increase of computational power has made viable the implementation of more and more sophisticated virtualization techniques. The use of virtualization in cluster environments to build ondemand computing infrastructures is a recent trend with a great potential. Cluster-based ..."
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Cited by 6 (1 self)
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Abstract. The continuous increase of computational power has made viable the implementation of more and more sophisticated virtualization techniques. The use of virtualization in cluster environments to build ondemand computing infrastructures is a recent trend with a great potential. Cluster-based network emulators are a specific class of cluster-based systems whose main purpose is to help researchers evaluate the effectiveness of new protocols and applications in realistic, synthetically generated network scenarios. Both large scale experimental testbeds (such as PlanetLab) and cluster-based network emulation systems (such as Emulab) use virtualization techniques at the basis of their resource management mechanisms to achieve isolation and concurrent experiments execution. In this paper, we compare different virtualization techniques already adopted in this kind of distributed systems and illustrate the peculiar virtualization requirements of a cluster-based network emulator. Furthermore, we show how Xen can be used to build a flexible and scalable network emulation system. 1
MM-ulator: Towards a Common Evaluation Platform for Mixed Mode Environments
, 2008
"... We investigate the interaction of mobile robots, relying on information provided by heterogeneous sensor nodes, to accomplish a mission. Cooperative, adaptive and responsive monitoring in Mixed-Mode Environments (MMEs) raises the need for multi-disciplinary research initiatives. To date, such resea ..."
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Cited by 2 (1 self)
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We investigate the interaction of mobile robots, relying on information provided by heterogeneous sensor nodes, to accomplish a mission. Cooperative, adaptive and responsive monitoring in Mixed-Mode Environments (MMEs) raises the need for multi-disciplinary research initiatives. To date, such research initiatives are limited since each discipline focusses on its domain specific simulation or testbed environment. Existing evaluation environments do not respect the interdependencies occurring in MMEs. As a consequence, holistic validation for development, debugging, and performance analysis requires an evaluation tool incorporating multi-disciplinary demands. In the context of MMEs, we discuss existing solutions and highlight the synergetic benefits of a common evaluation tool. Based on this analysis we present the concept of the MM-ulator: a novel architecture for an evaluation tool incorporating the necessary diversity for multi-agent hard-/software-in-the-loop simulation in a modular and scalable way.
Link Multiplexing in a Xen-based Network Emulation System
"... Abstract. Network emulation has gained wide interest in the community of network researchers to evaluate the effectiveness of new protocols and applications in controllable and realistic network scenarios. To ensure scalability, modern emulation systems rely on the use of virtualization techniques t ..."
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Abstract. Network emulation has gained wide interest in the community of network researchers to evaluate the effectiveness of new protocols and applications in controllable and realistic network scenarios. To ensure scalability, modern emulation systems rely on the use of virtualization techniques to create complex networked systems by means of the computational resources available in a cluster of computers. In the context of network emulation systems, link multiplexing is the problem of emulating multiple point-to-point connections on top of a single Ethernet link. In this paper we present how link multiplexing is implemented in NEP-TUNE, a Xen-based network emulation system developed at University of Napoli Federico II. We compare our technique with those adopted in other network emulation systems. We also present experimental results aimed at investigating the performance limits of our system and at providing researchers with useful insights into the faithfulness of emulated scenarios.
NETWORK EMULATION ON GLOBUS-BASED GRIDS: MECHANISMS AND CHALLENGES
"... Abstract In the last few years, many emulation systems have been developed to help researchers evaluate the effectiveness of new protocols and applications in realistic network scenarios. NEPTUNE (Network Emulation for Protocol TUNing and Evaluation) is a flexible and scalable system developed at Un ..."
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Abstract In the last few years, many emulation systems have been developed to help researchers evaluate the effectiveness of new protocols and applications in realistic network scenarios. NEPTUNE (Network Emulation for Protocol TUNing and Evaluation) is a flexible and scalable system developed at University of Napoli for the emulation of different network scenarios by means of a cluster of workstations. Setting up an emulation experiment in a cluster-based system requires, first, the ability to map virtual resources requested by an experimenter onto available physical resources and, second, the ability to exert a precise control over the allocated physical resources. These two requirements have much in common with resource management issues already addressed by the Grid computing community. Hence, we decided to exploit the virtual workspace concept at the foundation of the design of the NEPTUNE architecture. In this chapter, we illustrate the peculiar virtualization requirements of a cluster-based emulation system and discuss how a Globus Virtual Workspace based on Xen virtual machines can be used as the basis for implementing a distributed network emulation system. 1.
