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In telecommunication networks resilience intuitively refers to cycles and their lengths. More specifically, considering that the shortest cycle involving each pair of nodes in the network can be disassembled into two disjoint paths, a working path and a backup path, the average of the shortest cycles involving each pair of nodes in the network can be considered as an indicative of resilience. In turn,...
Aiming at providing united control of multi-domain optical networks orchestration, we design the Federated Platform based on Open Network Operating System (ONOS). Our implementation includes adding and extending modules in ONOS to provide the global view of multi-domain networks and support cross-domain end-to-end services by communicating with the individual domain controllers through RESTCONF protocol...
Optical networks are facing complexity and management challenges because a multi-technology infrastructure is required to support an ever-increasing traffic volume and dynamicity. In this heterogeneous context, we recently proposed a Cognitive Methodology to adjust the gain operating point of optical amplifiers using case-based reasoning. In this paper, we evaluate the execution time and introduce...
We present a heuristic algorithm to address the optimization problem of routing and spectrum allocation, aimed at traffic protection and restoration in an elastic optical network. The algorithm searches for working and backup disjoint paths, using the shared path protection scheme. It divides the spectrum into two partitions and prioritizes slots in one of them for backup path traffic. The way the...
We review our previously proposed topology reconstruction mechanism in the small world topology based optical data center network (DCN). We also present some recent experimental demonstration results, which verified that the topology reconstruction can reduce the number of hotspots and thus further accelerate data analysis jobs in DCN.
Aiming at efficiently mapping multiple virtual optical networks (VONs) on a shared substrate network. This paper proposes a load balancing algorithm that is based on key-link and resources contribution degree (RCD) for VONs mapping (KLRVM) in elastic optical networks (EONs). In this algorithm, virtual nodes mapping gets the network status according to the proposed RCD, and comprehensively considers...
Other than merely a bandwidth pipe, current and future network applications will have other requirements such as maximum end-to-end latency and the type of recovery from failure. The added complexity will require a central intelligence such as a software-defined networking (SDN) orchestrator to compute and keep track of the resources allocated to such applications. In such an SDN-orchestrated network,...
The growth of Internet traffic requires new strategies to offload congested Internet Protocol (IP) links. The introduction of sliceable optical networks resulted in appurtenance of new possibilities to manage this problem. In this paper, a dynamic sliceable optical bypassing policy is proposed to omit congested IP links in the software-defined networking (SDN) architecture. The experimental verification...
Topology reconstruction enables optical data center networks (DCNs) to adapt to dynamic traffic patterns, but may interrupt ongoing data transmissions. We propose a cross-layer mechanism to deliver traffic over multiple optical paths and adjust their TCP congestion windows coordinately. The experimental results show that it can effectively reduce the impacts on flow transmission.
Based on the small-world optical data center network architecture, we propose a topology-aw are task placement scheme. Simulation results verified that it can effectively shorten the completion time of computing tasks' data transfer.
An advanced dynamic spectrum allocation scheme based on fairness aware and fragmentation reduction is proposed to address the service fairness problem. Simulation results imply that the proposed scheme can greatly improve service fairness and reduce spectrum fragmentation.
The forecasted traffic growth makes the transmission capacity in backbone optical networks a scarce resource. Enabling the use of high-spectral-efficiency modulation formats (HSE-MFs) such as DQPSK or PM-QPSK for 40 or 100 Gbps respectively is one of the suggested on-going researches. However, some lightpaths may not require the highest rate and this call for mixed-line rate (MLR) networks. In MLR...
The Abstraction and Control of Traffic Engineered Networks (ACTN) defines the requirements, use cases, and an SDN-based architecture, relying on the concepts of network and service abstraction, detaching the network and service control from the underlying data plane. The architecture encompasses Physical Network Controllers (PNCs), responsible for specific technology and administrative domains, orchestrated...
This paper proposes a new networking paradigm introducing the broker-plane above the management planes of Autonomous Systems (ASes). The brokers communicate with the manager of each AS to coordinate end-to-end resource management and path provisioning across the multi-AS networks involving multiple operators. The broker plane updates the virtual network topology, manages the resource information of...
Multi-path allocation has been proposed as a simple way to achieve traffic protection in different networking domains. In this work dual-path allocation is proposed for Elastic Optical Networks (EON) assuming dynamic offered traffic, and its performance is quantified by simulation. Indeed, dual-path allocation is compared with partial dedicated path protection assuming different scenarios. In addition...
We review the statistical network assessment process (SNAP) and apply it to the analysis of two different network topologies. Using SNAP, we identify topological bottlenecks and we test the effectiveness of physical layer solutions in unlocking them. We show how selected introduction of spatial division multiplexing (SDM) through fiber doubling enables to achieving a 63% and 12% capacity increase...
We evaluate how the joint selective introduction of improved hybrid amplification technologies at inline amplification sites and advanced digital signal processing (DSP) techniques at transceivers allows to greatly reduce the number of required optical-electro-optical (OEO) regenerators in transparent optical networks. We perform quantitative studies on two different topologies, focusing on two different...
Space division multiplexing (SDM) seems to be a promising solution with the scaling potential to overcome the possible capacity crunch problem in optical backbone networks. The main goal of this paper is to provide a detailed analysis of three SDM scenarios, namely, SDM-Fixed, SDM-Single, and SDM-Flexible in terms of the spectrum usage and the wastage of spectral resources due to guardbands and resource...
One of the key enablers of the digital society is a highly reliable information infrastructure that can ensure resiliency to a wide range of failures and attacks. In cloud networks, replicas of various content are located at geographically distributed data centers, thus inherently enhancing cloud network reliability through diversification and redundancy of user accessibility to the content. However,...
Network operators must deal with multi-layer architectures in their production networks. Not so much time ago, network operators were delivering the IP traffic using ATM. ATM protocol was used to aggregate end-user traffic coming from DSL connections. This traffic was transported Synchronous Digital Hierarchy (SDH) as the standard transport technology for fiber-optic transmission systems in backbone...
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