2,799 research outputs found

    Resource virtualisation of network routers

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    There is now considerable interest in applications that transport time-sensitive data across the best-effort Internet. We present a novel network router architecture, which has the potential to improve the Quality of Service guarantees provided to such flows. This router architecture makes use of virtual machine techniques, to assign an individual virtual routelet to each network flow requiring QoS guarantees. We describe a prototype of this virtual routelet architecture, and evaluate its effectiveness. Experimental results of the performance and flow partitioning of this prototype, compared with a standard software router, suggest promise in the virtual routelet architecture

    Scalable Layer-2/Layer-3 Multistage Switching Architectures for Software Routers

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    Software routers are becoming an important alternative to proprietary and expensive network devices, because they exploit the economy of scale of the PC market and open-source software. When considering maximum performance in terms of throughput, PC-based routers suffer from limitations stemming from the single PC architecture, e.g., limited bus bandwidth, and high memory access latency. To overcome these limitations, in this paper we present a multistage architecture that combines a layer-2 load-balancer front-end and a layer-3 routing back-end, interconnected by standard Ethernet switches. Both the front-end and the back-end are implemented using standard PCs and open- source software. After describing the architecture, evaluation is performed on a lab test-bed, to show its scalability. While the proposed solution allows to increase performance of PC- based routers, it also allows to distribute packet manipulation functionalities, and to automatically recover from component failures

    Performance evaluation of an open distributed platform for realistic traffic generation

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    Network researchers have dedicated a notable part of their efforts to the area of modeling traffic and to the implementation of efficient traffic generators. We feel that there is a strong demand for traffic generators capable to reproduce realistic traffic patterns according to theoretical models and at the same time with high performance. This work presents an open distributed platform for traffic generation that we called distributed internet traffic generator (D-ITG), capable of producing traffic (network, transport and application layer) at packet level and of accurately replicating appropriate stochastic processes for both inter departure time (IDT) and packet size (PS) random variables. We implemented two different versions of our distributed generator. In the first one, a log server is in charge of recording the information transmitted by senders and receivers and these communications are based either on TCP or UDP. In the other one, senders and receivers make use of the MPI library. In this work a complete performance comparison among the centralized version and the two distributed versions of D-ITG is presented

    Design and Implementation of COTS-Based Aircraft Data Network Using Embedded Linux

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    Aircraft Data Network (ADN) is a data communication developed specifically for the aircraft environment. In such environments required data communication system that can work in real time and has a high level of reliability. One of the standards in ADN is Avionics Full-Duplex Switched Ethernet (AFDX) based on the ARINC 664 specification that is data communication standard for ADN that uses IEEE 802.3 standard on physical layer 1 and 2. It becomes the gap and challenge to implement the standard on the component of COTS By utilizing Linux-based embedded systems. The features designed and implemented in this paper are the switching and fault tolerant data components of ARINC 664. From the tests obtained, several results show that ADN functional features can be implemented and can simulate ADN mechanisms including fault tolerance capabilities. But there are performance limitations that the average jitter value of 3380 microseconds obtained has not met the requirements for use on aircraft that should be in the range of 500 microseconds

    Performance comparison of transmitting jumbo frame on Windows and Linux System

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    IPv6 is the successor of IPv4, the current Internet Protocol that runs out its address. It offers some improvements including simpler header format and extension header resulting in faster transmission of IP packets. However, IPv6 is a network layer protocol that requires lower layer services. IP packets from the network layer pass to data link layer to be encapsulated by layer 2 headers and trailer to become frames. Ethernet is the most widely used data link layer protocol in the current network devices. The technology is always improved to support high speed transmission. However, from standard Ethernet until ten gigabit Ethernet, the size of MTU remains unchanged at 1500 Bytes. This prevents the network from gaining an optimum performance on transmitting IP packets and operating systems cannot take full advantage of the high-speed performance of Gigabit Ethernet. This research aims to implement the transmission of IPv6 packets using jumbo frame on a test-bed environment. The implementation can be used to justify the impact of jumbo frame on the network as well as operating systems performance. The results prove that the OS used on implementation of jumbo frame affects on the network performance. The highest percentage of increasing throughput is 33.6% when both sender and receiver are running Windows. The decreasing delay by 54.36% was happened when using Linux in sender and Windows in receiver

    Experiences with high definition interactive video conferencing

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    We review the design and implementation of UltraGrid, a new high definition video conferencing system, and present some experimental results. UltraGrid was the first system to support gigabit rate high definition interactive video conferencing on commodity systems and networks, and we present measurements to illustrate behavior of production networks subject to such real time traffic. We illustrate the benefits of hybrid IP/provisioned optical networks over best effort IP networks for this class of traffic, and motivate the development of congestion control algorithms for interactive conferencing on best effort IP networks
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