The use of Space Division Multiplexing (SDM) technology in Elastic Optical Networks (EONs) is a promising solution to improve the transport capability and flexibility required by next-generation ...applications. In this work, we have illustrated that Ant Colony Optimization (ACO) algorithms can be incorporated into the network control plane and associated with a crankback mechanism to provision and restore lightpaths in a fully distributed manner. In effect, by tackling the challenging Routing, Modulation, Spectrum, and Space Assignment (RMSSA) problem, ACO algorithms can address the inter-core crosstalk and spectrum fragmentation that may limit the potential of the SDM-EON. By comparing different levels of resource state accuracy at the control plane, the simulation results demonstrate the superior performance of the ACO algorithms compared to routing algorithms based on a centralized control plane with a link-state routing protocol, showcasing lower bandwidth blocking rate, comparable restorability, controlled crosstalk levels, and higher scalability, all achieved without a significant increase in setup and restoration times.
Crankback re-routing extensions can offer significant improvements in the successful setup of Label Switched Paths (LSPs) by allowing new retries on alternate paths that circumvent blocked links or ...nodes. These extensions can be incorporated into a fully-distributed algorithm based on Ant Colony Optimization metaheuristics, taking advantage of its self-adapting, emergent behavior. By comparing with traditional fixed-alternate re-routing mechanisms, simulations have demonstrated that the proposed algorithm can efficiently mitigate lightpath blocking, both during normal operation and in case of network failure, by locally repairing failed LSP setups due to blocked/failed resources.
The management of multilayer networks is often a complex task, since each layer is typically independently operated and maintained, and there is a lack of shared network resource knowledge between ...layers. In this work, we have illustrated that Ant Colony Optimization (ACO) algorithms can be a suitable solution for coordinated management of disjoint IP and optical layers with limited or no visibility between the control planes of each layer. ACO algorithms are used to achieve fully-distributed multilayer routing policies in IP-over-optical networks. Simulations have demonstrated that ACO-based policies can achieve lower levels of blocking probability and higher levels of restorability for IP connections compared to fixed-alternate routing policies in almost all cases. This better performance is achieved with only small increases in the connection setup and restoration times, and without requiring a significant amount of communication overhead.
•Ant-based algorithms allow for distributed routing in IP/MLPS over optical networks.•Only local information is used in ant-based routing to avoid scalability issues.•Crankback is used to improve the setup and recovery of connections.•Setup latencies and network control overhead are kept at a reasonable level.•A comprehensive evaluation of different metrics in each network layer is presented.
Data transport infrastructures based on wavelength-routed optical networks are appealing to the grid community because they can provide a reconfigurable and high-bandwidth network service to emerging ...data-intensive grid applications. Traditionally, the control plane of those optical networks is independent from the management of other resources, such as computing systems, and it is commonly limited to fulfill immediate reservation demands of lightpaths. However, the lack of network integration to grid resources and the absence of advance reservation of bandwidth are critical aspects to the widespread adoption of optical networks in grid environments. Therefore, in this work, a distributed grid meta-scheduler based on an Ant Colony Optimization (ACO) algorithm is proposed, which is capable of co-allocating both optical networking and grid resources, under an integrated, extended and distributed control plane that supports advance reservations. The blocking probability and the delay for starting the processing of a request are evaluated for the proposed meta-scheduler under different resource co-allocation algorithms and different meta- and local scheduling policies, including the influence of the information aggregation across grid nodes. In addition, the benefits of the proposed approach are shown, such as grid and networking resource integration at the control plane, and capital expenditure reductions at the deployed optical network when compared to an immediate reservation scenario.
•Ant Colony Optimization is a viable framework for meta-scheduling in lambda grids.•An integrated control plane for co-allocating grid and networking resources is shown.•Three different resource co-allocation algorithms are proposed and evaluated.•RSVP-TE signaling protocol is extended to support advance reservation of resources.•Local scheduling and information aggregation affect meta-scheduling performance.
Byzantine failures during the execution of the routing algorithm may degrade or disrupt the normal operation of the network. Ant Colony Optimization (ACO)-based routing algorithms are especially ...vulnerable to those failures. In this work, we propose the use of crankback re-routing extensions associated to the ACO algorithm in wavelength-routed optical networks to deal with byzantine failures. We investigate three different byzantine failure scenarios: misdirection of forward ants, dropping of forward ants and dropping of backward ants. Those failures affect the routing information of the network, but they are very hard to detect and cannot be fully addressed by integrity and authentication techniques. Without any need for a byzantine failure detection mechanism, simulations have demonstrated that the proposed approach is effective in mitigating the impact on the blocking probability due to network nodes exhibiting a byzantine behavior.
The HTTP/2 protocol introduces the concept of request prioritization, where the client manifests to the server its preferences for completing important requests more quickly. In this work, we propose ...that this prioritization can also occur at the network layer with the help of a software-defined network. By classifying and marking the streams, which are related to the most critical resources needed for web page rendering, as high-priority traffic, it is possible to obtain a better Quality-of-Experience (QoE) for the web users. To demonstrate the benefits of the proposed approach, a prototype was built to emulate a software-defined wide area network, where paths with different Quality-of-Service (QoS) characteristics were available. The SpeedIndex metric was used to measure the QoE for the Alexa top 9 sites on the web. The obtained results indicate that the proposed approach can significantly improve the QoE in lossy environments, which are known to be challenging to the HTTP/2 protocol.
The use of a dynamic reconfigurable optical network is an important requirement for the new advanced resource-intensive, highly distributed Grid applications that begin to emerge on the e-Science ...field. In this paper, we propose an ACO-based algorithm that is capable of the co-scheduling of both computational and optical network resources. We assess the performance of the proposed algorithm by comparison with traditional publish-and-subscribe grid systems that make use of topological routing of the lightpaths. The proposed algorithm can be used as a viable alternative for grid scheduling in Lambda Grids.
This work proposes two different distributed strategies for provisioning lightpaths in the presence of optical physical-layer impairments in GMPLS networks. The first approach is a more classical ...one, which introduces new extensions to the OSPF-TE routing protocol. The other approach makes use of an Ant Colony Optimization (ACO) algorithm to adaptively calculate routes in the network by actively monitoring the aggregate optical power of each link.
By using an analytical model to incorporate the constraints of the Amplified Spontaneous Emission (ASE) noise of the optical amplifiers into the routing, we demonstrate the effectiveness of our approaches by means of an illustrative numerical example.
Because of the distributed control of the network, the dynamic nature of the traffic and the unpredictability of a failure event, the flexibility and robustness of ant colony optimization (ACO) make ...it a suitable candidate for provisioning lightpaths in an optical network. In this work, we propose a fault-tolerant dynamic routing and wavelength assignment (RWA) algorithm based on the ACO framework, presenting its integration into the Generalized multi-protocol label switching (GMPLS) control plane. By simulating two different scenarios, we demonstrate the effectiveness of this algorithm when a single link or node failure occurs.
In this work, we propose the use of an Ant Colony Optimization (ACO) algorithm to mitigate packet loss in an optical packet switching network that carries self-similar traffic, which is known to have ...a great impact in the buffer performance in terms of loss probability as exemplified in this work. By adaptively routing the packets and balancing the network load, we demonstrate by some simulations the effectiveness of this approach when compared with a shortest-path routing scheme, achieving a performance that is comparable to the Poisson traffic scenario in some cases. The proposed algorithm can be used as a viable alternative to traffic shaping techniques.
