In this work, we present ElasticO++: an Elastic Optical Network Simulation Framework for OMNeT++. A tool created to enable testing in a whole range of routing, modulation, spectrum assignment, defragmentation algorithms, parameters, and topologies. To the best of our knowledge, the proposed framework is the first software available capable of working with fragmentation and defragmentation in dynamic network scenarios. The flexibility available on the proposed tool allows both academia and industry develop new algorithms and techniques for Elastic Optical Networks. The framework provides a set of instruments that allow rapid implementation, testing, and analysis of new algorithms; and enables a common and well-controlled environment for comparing existing algorithms. In its current version, the framework comes with ten traditional already implemented algorithms, which can be used standalone or in combination with new ones. This work describes the architecture and main features, which makes our framework unique. Additionally, we present a case study to demonstrate some of the proposed framework capabilities.

Programmable networks are a substantial part of current R&D on future internet (FI) in Europe and worldwide, with considerable impact generated by large-scale test bed infrastructures. In such test beds, researchers validate proof-of-concept prototypes for new algorithms and mechanisms for efficiently controlling and managing network resources. One of the key domains for FI research is software-defined networking (SDN), which creates innovations in existing Internet architectures by shifting the control and logic outside the network equipment to Data Centres. International cooperation among leading research centres in Europe, Americas and Asia is key to validate SDN foundations and tools. EU and Japan have jointly funded the FELIX project (federated test-beds for large-scale infrastructure experiments), which defines a common control and orchestration framework to manage federated FI test beds across continents. This framework enables an experimenter to (i) request and obtain resources across different test bed infrastructures dynamically; (ii) manage and control the network paths connecting the federated SDN test beds; (iii) monitor the underlying resources and (iv) use distributed applications executed on the federated infrastructures. This paper describes the high-level architecture of the FELIX framework and details six use cases that will be employed for validation. We present our analysis and end-user considerations, highlighting the necessity for resource accessibility and coherent use of physical connections over a large-scale test bed where different control technologies such as OpenFlow and the network service interface (NSI) are simultaneously used.

We propose a Routing and Spectrum Assignment algorithm to address Spectrum Fragmentation, and unfairness among different rated requests in Elastic Optical Networks. Results show that our method achieves desired fairness and reduces blocked bandwidth ratio.

In order to detect and prevent DoS/DDoS attacks that exploit IP address spoofing, the IP traceback technique has been introduced and developed with variety of methods including packet marking. By means of inserting marking information on the travel path into rarely used fields in the header of IP packets, the destination host can trace back the original-source location of received packets, which is useful for supporting detection of attacks. Many schemes of packet marking IP traceback have been proposed, but still have nevertheless some drawbacks such as low traceback rate, heavy computational overhead due to high-required number of marked packets and marking size. In this paper, we proposed PLA DFM, a novel efficient enhanced solution of Deterministic Flow Marking based on adaptation with real traffic characteristics. The analytic result shows that the proposed solution provides a far higher successful mark rate, lower computational overhead compared to the original scheme and other marking techniques with unnoticeable increased traffic size.

Network programmability emerges as a key ingredient of Future Internet testbeds, which are established through international collaborations across country boundaries throughout Europe and around the world. Software Defined Networking challenges long-established invariants of the Internet architecture and fosters a paradigm shift in the way we design and operate networks, and enables the establishment of larger and more diverse advanced programmable network testbeds with a global scale. This paper surveys several programmable testbed networks in Europe (FIRE) and Japan, from which we derive the requirements for federating SDN testbeds between the two regions.

International cooperation on Software-Defined Networking (SDN), crossing the boundaries of Europe, the Americas and Asia, builds a strong foundation for pursuing experimental research through advanced programmable network testbeds. The EU-Japan jointly-funded project FELIX (FEderated Testbeds for Large-scale Infrastructure eXperiments) considers the definition of a common framework for federated Future Internet (FI) testbeds, which are dispersed across continents. This framework will enable an experimenter to (i) request and obtain resources across different testbed infrastructures dynamically; (ii) manage and control the network paths connecting the federated SDN testbed infrastructures; (iii) monitor the underlying resources; and (iv) use distributed applications executed on the federated infrastructures. This paper details six use cases that will be employed to validate the FELIX architecture and software platforms. We present our analysis and end-user considerations, highlighting the necessity to have a global vision of issues within the testbed network. Resource reachability and coherent use of physical connections are key factors in the use cases. This is particularly important when considering the simultaneous use of different technologies such as OpenFlow and the Network Service Interface (NSI) among others.

The growth of the Internet in terms of number of devices, the number of networks associated to each device and the mobility of devices and users makes the operation and management of the Internet network infrastructure a very complex challenge. In order to address this challenge, innovative solutions and ideas must be tested and evaluated in real network environments and not only based on simulations or laboratory setups. OFELIA is an European FP7 project and its main objective is to address the aforementioned challenge by building and operating a multi-layer, multi-technology and geographically distributed Future Internet testbed facility, where the network itself is precisely controlled and programmed by the experimenter using the emerging OpenFlow technology. This paper reports on the work done during the first half of the project, the lessons learned as well as the key advantages of the OFELIA facility for developing and testing new networking ideas. An overview on the challenges that have been faced on the design and implementation of the testbed facility is described, including the OFELIA Control Framework testbed management software. In addition, early operational experience of the facility since it was opened to the general public, providing five different testbeds or islands, is described.

The energy consumption in telecommunication networks is expected to grow considerably, especially in core networks. In this chapter, optimization of energy consumption is approached from two directions. In a first study, multilayer traffic engineering (MLTE) is used to assign energy-efficient paths and logical topology to IP traffic. The relation with traditional capacity optimization is explained, and the MLTE strategy is applied for daily traffic variations. A second study considers the core network below the IP layer, giving a detailed power consumption model. Optical bypass is evaluated as a technique to achieve considerable power savings over per-hop optical–electronic–optical regeneration.

Multilayer traffic engineering (MLTE) allows coping with ever-increasing and varying traffic demands in IP-over-Optical multilayer networks. It utilizes cross-layer TE (Traffic Engineering) techniques to provision optical lightpath capacity to the IP/MPLS (Internet Protocol/ Multi-Protocol Label Switching) logical topology on-demand. Such provisioning however causes optical connection arrival rates that pose strong performance requirements to Routing and Wavelength Assignment (RWA) strategies. Collecting up-to-date network information for the RWA with rapidly changing network states can be quite difficult. Exposing optical layer state information to the IP layer in the overlay model, or transforming this optical layer information in a workable representation in an integrated control plane is similarly problematic. Prediction-Based Routing (PBR) has been proposed as a RWA mechanism for optical transport networks; it bases routing not on possibly inaccurate or outdated network state, but instead on previous connections set-up. In this article, we propose to implement PBR as the RWA mechanism in the optical layer of a multilayer network, and use the predictive capabilities of PBR to expose dynamic optical network information into the multilayer traffic engineering algorithm with minimal control plane overhead. Some simulations show the benefits of using the PBR in the optical layer for MLTE purposes.

We demonstrate machine learning augmented Open Shortest Path First (OSPF) routing which infers Shared Risk Groups (SRG) from link failure history. For an initial link failure matching an SRG, it predicts subsequent link state advertisements corresponding with that SRG, improving convergence and recovery times during multiple network failures.

Failing to account for the set of links affected by a simultaneous dependent failure during the re-computation of the routing table entries leads to traffic losses until all failed links have been accounted in the re-computation of these entries. Instead, if the router learns about the existence of Shared Risk Link Groups (SRLGs) from the arriving pattern link state routing information, then decisions regarding SRLG failure can be taken promptly to avoid successive re-computations of alternate shortest paths across the updated topology. In this paper, we propose a mechanism to improve the router recovery time upon occurrence of topological link failures by detecting and identifying the existence of SRLGs from link state routing information exchanged in the routing domain. The proposed model first groups into events individual Link State Advertisements (LSAs) issued by different network nodes (routers) upon link state change; then, it combines this information to find temporal dependence among members of event groups. It further introduces a physical model interpretation derived from the application of the Weibull distribution, to determine the error on the joint probabilities of events resulting from the finite observation sample. This association allows binding the dependence of the identified groups comprising one or more events (associated to SRLG) on the corresponding estimated failure rate. Our simulation results show that the proposed technique to locally detect and identify SRLGs performs sufficiently well to trigger with enough confidence simultaneous routing table updates from the arrival of a reduced set of LSAs (ideally one).

IP-based backbone networks are gradually moving to a network model consisting of high-speed routers that are flexibly interconnected by a mesh of light paths set up by an optical transport network that consists of wavelength division multiplexing (WDM) links and optical cross-connects. In such a model, the generalized MPLS protocol suite could provide the IP centric control plane component that will be used to deliver rapid and dynamic circuit provisioning of end-to-end optical light paths between the routers. This is called an automatic switched optical (transport) network (ASON). An ASON enables reconfiguration of the logical IP topology by setting up and tearing down light paths. This allows to up- or downgrade link capacities during a router failure to the capacities needed by the new routing of the affected traffic. Such survivability against (single) IP router failures is cost-effective, as capacity to the IP layer can be provided flexibly when necessary. We present and investigate a logical topology optimization problem that minimizes the total amount or cost of the needed resources (interfaces, wavelengths, WDM line-systems, amplifiers, etc.) in both the IP and the optical layer. A novel optimization aspect in this problem is the possibility, as a result of the ASON, to reuse the physical resources (like interface cards and WDM line-systems) over the different network states (the failure-free and all the router failure scenarios). We devised a simple optimization strategy to investigate the cost of the ASON approach and compare it with other schemes that survive single router failures.

One of the main challenges for the future of information and communication technologies is reduction of the power consumption in telecommunication networks. The key consumers are the home gateways at the customer premises for fixed line access technologies and the base stations for wireless access technologies. However, with increasing bit rates, the share of the core networks could become significant as well. In this article we characterize the power consumption in the different types of networks and discuss strategies to reduce the power consumption.

High-bandwidth QoS sensitive services such as large scale video surveillance generally depend on provisioned capacity delivered by circuit-switched technology such as SONET/SDH. Yet development in layer 2 protocol sets and manageability extensions to Ethernet standards propose layer 2 packet switching technology as a viable, cheaper alternative to SONET/SDH. Layer 2 switched networks traditionally offer more complex topologies; in this paper we explain general QoS issues with layer 2 switching and show the impact of topology choice on service performance.

Automatically switched multilayer IP-over-optical networks offer extensive flexibility in adapting the network to offered IP/MPLS traffic. Multilayer traffic engineering (MLTE) takes advantage of this through online IP logical topology reconfiguration in addition to the more traditional rerouting. The main goal of MLTE is to optimize toward resource usage, bandwidth throughput and QoS performance. However, energy efficiency of ICT infrastructure and the network in particular more recently have become an important aspect as well. In this article, we will look how MLTE helps in improving network energy efficiency. For this we will explain how optimization toward power requirement relates to the traditional resource usage minimization objective, and how power requirement in the network can be modeled for the MLTE algorithm. We will discuss two cases where the merit of MLTE for energy efficiency is discussed. Firstly, we will examine the interaction of MLTE with hardware-based energy efficiency optimization techniques; for this we look at scaling back power requirements through the use of better chip technology, but also decreasing idle-power requirement only, using improved chip architecture. Secondly, as MLTE allows for fast responses to changing traffic, we will see how link switch-off during off-peak hours offers a straightforward option to reduce energy needs.

Both bandwidth demand and energy consumption of ICT and communication networks is increasing and optical networks are regarded to provide high bandwidth solutions while enabling more energy efficiency. In this article we give an overview of energy consumption in access and core networks with a focus on optical technologies. Also, possible strategies to enable power reductions are discussed.

The ECODE FP7 project researches cognitive routing functions in future networks. We demonstrate machine learning augmented OSPF routing which infers SRLGs from network failure history. Inferred SRLGs are used to improve OSPF convergence and recovery times during subsequent (multiple) network failures.

Simulation shows how energy efficiency aware multilayer traffic engineering taking into account network equipment power characteristics can optimize IP-over-optical networks for diurnal traffic variations, lowering total power requirements.

Network resilience is an issue of deep concern to network operators being eager to deploy high-capacity fibre networks, since a single failure in the network could result in significant losses of revenue. The importance of network reliability will keep pace with the steadily increasing network capacity. For very-high-capacity future optical networks, carrying multitudes of 10 Gbit/s channels per fibre strand, a failure of optical connection will interrupt a vast amount of services running on-line, making the connection availability a factor of great significance. Therefore the ultrahigh capacity future optical networks will face a challenge of providing very efficient and fast survivability mechanisms. In this chapter we review the terminology and basic resilience techniques along with the results of research work on optical network survivability performed in the frame of COST291 cooperation. Our research work was focused on reliability performance improvement and on recovery in multilayer optical networks.

There is a general agreement that the future infrastructure for broadband communications will consist of Automatically Switched Optical Networks (ASONs) controlled by the Generalized Multi-Protocol Label Switching (GMPLS) control plane. Due to the convergence of most services on the Internet Protocol (IP) layer, ASON/GMPLS networks need to provide transport for a variety of applications having different Quality of Service (QoS) requirements. This implies that the Differentiated Service paradigm, which improves the QoS in pure IP networks, needs to be extended to the new underlying infrastructure. This article proposes and compares three schemes for the service differentiation in IP/MPLS over ASON/GMPLS networks. Simulation results demonstrate that a fair trade-off between QoS and resource utilization is achieved when combining routing policy differentiation (RPD), virtual topology differentiation (VTD), and virtual topology sharing (VTS) techniques. The RPD technique decides on the multilayer routing policy to apply depending on the Class of Service (CoS). The VTD technique transports different CoS over different independent virtual topologies. The VTS technique introduces a certain degree of resource sharing among the different virtual topologies.