1,595 research outputs found
Measurement Based Reconfigurations in Optical Ring Metro Networks
Single-hop wavelength division multiplexing (WDM) optical ring networks operating in packet mode are one of themost promising architectures for the design of innovative metropolitan network (metro) architectures. They permit a cost-effective design, with a good combination of optical and electronic technologies, while supporting features like restoration and reconfiguration that are essential in any metro scenario. In this article, we address the tunability requirements that lead to an effective resource usage and permit reconfiguration in optical WDM metros.We introduce reconfiguration algorithms that, on the basis of traffic measurements, adapt the network configuration to traffic demands to optimize performance. Using a specific network architecture as a reference case, the paper aims at the broader goal of showing which are the advantages fostered by innovative network designs exploiting the features of optical technologies
A fully SDN enabled all-optical architecture for data centre virtualisation with time and space multiplexing
© 2018 [2018 Optical Society of America.]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.Virtual Data Centre (VDC) solutions provide an environment that is able to quickly scale-up and where virtual machines and network resources can be quickly added on-demand through self-service procedures. VDC providers must support multiple simultaneous tenants with isolated networks on the same physical substrate. The provider must make efficient use of their available physical resources whilst providing high bandwidth and low-latency connections to tenants with a variety of VDC configurations. This paper utilises state of the art optical network elements to provide high bandwidth optical interconnections and develop an VDC architecture to slice the network and the compute resources dynamically, to efficiently divide the physical network between tenants. We present a Data Centre Virtualisation architecture with an SDN-controlled all-optical data plane combining Optical Circuit Switching (OCS) and Time Shared Optical Network (TSON). Developed network orchestration dynamically translates and provisions VDCs requests onto the optical physical layer. The experimental results show the provisioned bandwidth can be varied by adjusting the number of time slots allocated in the TDM network. These results lead to recommendations for provisioning TDM connections with different performance characteristics. Moreover, application level optical switch reconfiguration time is also evaluated to fully understand the impact on application performance in VDC provision. The experimental demonstration confirmed the developed VDC approach introduces negligible delay and complexity on the network side.Peer ReviewedPostprint (author's final draft
Applications of satellite technology to broadband ISDN networks
Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about 250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization
PI-OBS: a Parallel Iterative Optical Burst Scheduler for OBS networks
This paper presents the PI-OBS algorithm, a parallel-iterative scheduler for OBS nodes. Conventional schemes are greedy in the sense that they process headers one by one. In PI-OBS, all the headers received during a given time window are jointly processed to optimize the delay and output wavelength allocation, applying void filling techniques, and allowing traffic differentiation. Results show a similar or better performance than the LAUC-VF algorithm, commonly used as a performance bound for OBS schedulers. The PI-OBS scheduler has been designed to allow parallel electronic implementation similar to the ones in VOQ schedulers, with a deterministic response time.This research has been partially supported by the MEC projects
TEC2007-67966-01/TCM CON-PARTE-1, and TEC2008-02552-E,
and it is also developed in the framework of "Programa de Ayudas a
Grupos de Excelencia de la R. de Murcia, F. Séneca"
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An Overview of the Isochronets Architecture for High Speed Networks
This paper overviews a novel switching architecture for high-speed networks: Isochronets. Isochronets time-divide network bandwidth among routing trees. Traffic moves down a routing tree to the root during its time band. Network functions such as routing and flow control are entirely governed by band timers and require no processing of frame headers bits. Frame motions need not be delayed for switch processing, allowing Isochronets to scale over a large spectrum of transmission speeds and support all-optical implementations. The network functions as a media-access layer that can support multiple framing protocols simultaneously, handled by higher layers at the periphery. Internetworking is reduced to a simple media-layer bridging. Isochronets provide flexible quality of service control and multicasting through allocation of bands to routing trees. They can be tuned to span a spectrum of performance behaviors outperforming both circuit or packet switching
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