521 research outputs found

    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

    Functional requirements document for NASA/MSFC Earth Science and Applications Division: Data and information system (ESAD-DIS). Interoperability, 1992

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    These Earth Science and Applications Division-Data and Information System (ESAD-DIS) interoperability requirements are designed to quantify the Earth Science and Application Division's hardware and software requirements in terms of communications between personal and visualization workstation, and mainframe computers. The electronic mail requirements and local area network (LAN) requirements are addressed. These interoperability requirements are top-level requirements framed around defining the existing ESAD-DIS interoperability and projecting known near-term requirements for both operational support and for management planning. Detailed requirements will be submitted on a case-by-case basis. This document is also intended as an overview of ESAD-DIs interoperability for new-comers and management not familiar with these activities. It is intended as background documentation to support requests for resources and support requirements

    Boosting the Performance of PC-based Software Routers with FPGA-enhanced Network Interface Cards

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    The research community is devoting increasing attention to software routers based on off-the-shelf hardware and open-source operating systems running on the personalcomputer (PC) architecture. Today's high-end PCs are equipped with peripheral component interconnect (PCI) shared buses enabling them to easily fit into the multi-gigabit-per-second routing segment, for a price much lower than that of commercial routers. However, commercially-available PC network interface cards (NICs) lack programmability, and require not only packets to cross the PCI bus twice, but also to be processed in software by the operating system, strongly reducing the achievable forwarding rate. It is therefore interesting to explore the performance of customizable NICs based on field-programmable gate array (FPGA) logic devices we developed and assess how well they can overcome the limitations of today's commercially-available NIC

    An efficient asynchronous spatial division multiplexing router for network-on-chip on the hardware platform

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    The quasi-delay-insensitive (QDI) based asynchronous network-on-chip (ANoC) has several advantages over clock-based synchronous network-on-chips (NoCs). The asynchronous router uses a virtual channel (VC) as a primary flow-control mechanism however, the spatial division multiplexing (SDM) based mechanism performs better over input traffics over VC. This manuscript uses an asynchronous spatial division multiplexing (ASDM) based router for NoC architecture on a field-programmable gate array (FPGA) platform. The ASDM router is configurable to different bandwidths and VCs. The ASDM router mainly contains input-output (I/O) buffers, a switching allocator, and a crossbar unit. The 4-phase 1-of-4 dual-rail protocol is used to construct the I/O buffers. The performance of the ASDM router is analyzed in terms of lower urinary tract symptoms (LUTs) (chip area), delay, latency, and throughput parameters. The work is implemented using Verilog-HDL with Xilinx ISE 14.7 on artix-7 FPGA. The ASDM router achieves % chip area and obtains 0.8 ns of latency with a throughput of 800 Mfps. The proposed router is compared with existing asynchronous approaches with improved latency and throughput metrics

    Design and implementation 4x4 Network on Chip (NoC) using FPGA

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    The Network on chip is one of the most crucial in the development of the networks and routers in new days due to the improvement that make through way of sending huge packets of data and technology and protocol that used for sending the packets between IP cores. Also the NoC is removed the old ways of technique and protocols of sending packets through routers. The NoC is the most enhanced and efficient in working in parallel ways. Hence, Field Program Gate Array (FPGA) is used in the designing of router that its architecture depending on the NoC. The research proposed in this paper proposed 4x4 nodes router with mesh network that support two dimensional architecture. A real time test is used for experimental through FPGA and the test verified efficient packets transporting via two array buffers that integrated in the proposed router architecture

    Adaptive Load Sharing for Network Processors

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    A novel scheme for processing packets in a router is presented, which provides for load sharing among multiple network processors distributed within the router. It is complemented by a feedback control mechanism designed to prevent processor overload. Incoming traffic is scheduled to multiple processors based on a deterministic mapping. The mapping formula is derived from the robust hash routing (also known as the highest random weight - HRW) scheme, introduced in K.W. Ross, IEEE Network, 11(6), 1997, and D.G. Thaler et al., IEEE Trans. Networking, 6(1), 1998. No state information on individual flow mapping needs to be stored, but for each packet, a mapping function is computed over an identifier vector, a predefined set of fields in the packet. An adaptive extension to the HRW scheme is provided in order to cope with biased traffic patterns. We prove that our adaptation possesses the minimal disruption property with respect to the mapping and exploit that property in order to minimize the probability of flow reordering. Simulation results indicate that the scheme achieves significant improvements in processor utilization. A higher number of router interfaces can thus be supported with the same amount of processing power

    Software Patterns for Asymmetric Multiprocessing Devices on Embedded Systems: a performance assessment

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    In emnedded systems there is a variant of Multicore System on Chip devices (MSoC devices) where not all the computing elements (processor cores) are equal. The differences in the cores of these devices range from different hardware architectures using the same instruction set to completely different processors working together inside the same device. These SoCs are called “Asymmetric Multi Processing Devices” (AMP Devices). In order to help developers to take advantage of the possinilities that these devices may offer in the context of emnedded systems, software design patterns have neen defined, descrining software architectural solutions with known uses. However, there are still no experimental results showing the nenefits of these solutions. In this work we measure the performance of a design pattern called Mini Me, applied on an AMP device configuration, and compare it against two Symmetric Multiprocessing Device (SMP Device) configurations. The evaluations show a netter than expected computing performance of the AMP Configuration using the design pattern Mini Me.Laboratorio de Investigación y Formación en Informática Avanzad
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