1,721,066 research outputs found
Locally automated restoration in SDN disaggregated networks
Full text linkMulti-vendor interoperability and disaggregation are attracting the interest of network operators as a way to avoid vendor lock-in, thus opening the market and, possibly, reducing costs. NETCONF, in concert with YANG data models, has been identified as the software defined networking (SDN) configuration protocol for these networks. Currently, several YANG models describe devices in a vendor-neutral way; however, there is a lack of YANG models describing functions. Moreover, the centralization of the control plane may suffer from scalability issues during critical situations (e.g., link failures), given that several restoration requests will arrive at the SDN controller close in time. This paper investigates an innovative paradigm of restoration for disaggregated SDN networks named delegated restoration, which operates in a hybrid centralized-distributed manner. Before a failure occurs, the backup lightpath is centrally computed by the SDN controller, and, based on this computation, the controller informs the network devices (switches and transponders), through NETCONF, of the reconfigurations to perform in case of failure. Simulations show that delegated restoration can reduce the restoration time with respect to a fully centralized approach, making it a candidate for impacting the operation, administration, and maintenance of next-generation networks
Exploiting spectrum sharing for soft failure recovery
No full textElastic optical networks (EONs) offer several optimization dimensions that can be harvested to increase network efficiency and survivability. More specifically, the adaptation of the modulation format to a more robust one can recover the quality of transmission (QoT) of a lightpath affected by a soft failure (i.e., a physical layer degradation resulting in QoT deterioration). In this scenario, increasing the robustness of a transmission may require a spectrum increase. Thus, the spectrum also might have to be reconfigured. In this paper, we propose spectrum sharing between lightpaths of classes requiring different rate guarantees. In the case of a soft failure, a high-priority, rate-guaranteed lightpath can expand its spectrum to recover its QoT at the expense of spectrum allocated to a lower-priority, guaranteed minimum rate lightpath. We propose an integer linear programming (ILP) routing and spectrum assignment (RSA) algorithm for the planning phase and an online RSA for the operation phase of the network that optimize spectrum sharing among lightpaths of different classes. Using these proposed techniques can effectively reduce the network costs to guarantee the rate of high-priority connections
Multiband Optical Networks Control and Provisioning
No full textThis paper presents viable solutions for the control of a multi-band optical network. NETCONF and augmented OpenConfig YANG data models are adopted to configure and monitor the state of network devices. Both connection provisioning and Quality of transmission estimation account for Stimulated Raman Scattering
Experimental Optimization of Spectrum-Efficient Super-Channels in Elastic Optical Networks
No full textAutomatic super-channel optimization is experimentally demonstrated using a 600Gb/ s transponder in the SDN-controlled Elastic Optical Network. Margin reduction while guaranteeing Quality of Transmission allows for a spectrum occupation reduction of 25%
Network Authentication, Identification, and Secure Communication through Optical Physical Unclonable Function
No full textMulticarrier Transmission Optimization in Elastic Optical Networks
No full textThis study investigates the trade-off between Quality of Transmission (QoT) performance and spectrum efficiency through low-margin operation of multicarriers. Margin reduction is enabled by implementing tight filtering and slight subcarriers overlap. Experiments conducted on a Software Defined Networking (SDN)-controlled Elastic Optical Network (EON) testbed demonstrate spectrum-efficient multicarriers composed of three subcarriers, achieving savings of up to 22% in spectrum occupation for 80 km optical connections
Neural Network-Based Control of TDFA
No full textThe complexity of controlling optical amplifiers with multiple pumps, like Thulium-Doped Fiber Amplifiers (TDFAs), stems from the need to select the optimal pumping to ensure proper operation (e.g., maintaining a constant target output power). Therefore, an experimental demonstration of neural network-assisted SDN control of TDFA configuration is presented. The proposed optimization enables efficient automated TDFA control, resulting in an RMSE of 0.23 dBm between target and actual output power
Impact of the Interplay Between Mode Dispersion and Kerr Effect in SDM Optical Networks
No full textSpace division multiplexing (SDM) - such as based on multi-mode fibers - is under investigation to support the growing capacity demands. In optical networks, the estimation of quality of transmission (QoT) is a fundamental control task to identify the most suitable transmission parameters (e.g., modulation format) to meet proper spectral efficiency while satisfying the required optical reach. The Gaussian Noise (GN) model is widely adopted for QoT estimation. However, the basic version of the GN model does not account for the interplay between mode dispersion and the Kerr effect. In this paper, we investigate the impact of mode dispersion on SDM networks exploiting strongly coupled modes, through an extended GN model. Network performance analysis is evaluated. First, an analysis of the achievable information rate (AIR) with Gaussian data statistics is presented. Then, a network capacity analysis is shown constrained to a set of supported modulation formats and a fixed symbol rate. Finally, blocking probability is studied with the same set of supported modulation formats with variable symbol rates. The presented network analysis shows that accounting for mode dispersion increases the throughput considering: i) Gaussian data statistics, ii) different modulation formats. Moreover, the blocking probability analysis shows a blocking reduction when mode dispersion is considered in the physical layer modeling
Experimental Optimization of Power-Aware Super-Channels in Elastic Optical Networks
No full textPower-Aware super-channel optimization is experimentally demonstrated using a 600Gbit/s transponder in the SDN-controlled Elastic Optical Network. The trade-off between power consumption and spectrum efficiency is investigated by operating super-channels at nominal and low-margin conditions. Results show that physical layer and operational modes impact power consumption regardless of the spectrum efficiency. Experiments on 800 Gbit/s super-channels show 7% power saving when super-channels are operated at nominal spectrum usage
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