Laurent Ciavaglia

Standardizing a reference model and autonomic network architectures for the self-managing future internet

Research efforts at network design in the area of Autonomic Networking and Self-Managing Networks have reached a maturity level that forms a strong foundation toward standardization of architectural principles of the Self-Managing Future Internet. Therefore, an Industry Specification Group (ISG) on Autonomic network engineering for the self-managing Future Internet (AFI) has been established under the auspices of the European Telecommunications Standards Institute (ETSI). Upon its creation, the main stakeholders agreed to harmonize the previous developments and the most recent trends in the very vital field of autonomic and self-managing networks. Particularly, the life cycle of AFI is structured by Work Items providing the foundation for ETSI Group Specifications. So far AFI has been focusing on scenarios, use cases, and requirements for the autonomic/selfmanaging Future Internet, as well as on architectural reference model for autonomic networking and self-management. Most recently, AFI has continued with a new Work Item on requirements analysis and specification of implementation-oriented solutions for autonomics and self-management. At the same time, as a part of the global ecosystem, AFI is establishing strategic liaisons with the standards developing organizations and research community.

Resolving the fairness issue in bus-based optical access networks

Packet-based optical access ring is becoming a promising solution in metropolitan networks. Its performance depends mainly on how optical resource sharing takes place among the different competing access nodes. This network architecture has mostly been explored with regard to synchronous transmission (i.e., slotted WDM ring). However, in this article we focus on the performance of asynchronous transmission-based networks with variable packet sizes. We investigate the fairness issue that is likely to arise between upstream and downstream nodes sharing a common data channel. Furthermore, we show that sharing the channels available bandwidth fairly but arbitrarily between access nodes, as in slotted WDM rings, does not resolve the fairness problem in asynchronous systems. In this regard, we exhibit the inherent limitations of the token bucket access rate-based algorithm once applied to asynchronous transmission bus-based networks. To alleviate the aforementioned problem, we devise a new strategy called traffic control architecture using remote descriptors (TCARD). The proposed solution is based on a preventive mechanism to grant access to the shared resource. As illustrated in the article, the proposed solution alleviates performance degradation and resource underutilization while achieving fairness among bus nodes.

Optimization of fault diagnosis based on the combination of Bayesian Networks and Case-Based Reasoning

Fault diagnosis is one of the most important tasks in fault management. The main objective of the fault management system is to detect and localize failures as soon as they occur to minimize their effects on the network performance and therefore on the service quality perceived by users. In this paper, we present a new hybrid approach that combines Bayesian Networks and Case-Based Reasoning to overcome the usual limits of fault diagnosis techniques and reduce human intervention in this process. The proposed mechanism allows identifying the root cause failure with a finer precision and high reliability while reducing the process computation time and taking into account the network dynamicity.

Distributed aggregation in all-optical wavelength routed networks

In this paper, we propose and evaluate a new concept of traffic aggregation in mesh networks that aims to eliminate the bandwidth underutilization problem existing in all-optical wavelength routed networks. The proposed solution is based on the distribution of the aggregation process. So, instead of limiting the utilization of lightpaths capacity to the ingress node, each node along the path is allowed to fill on the fly this optical resource according to its availability. Therefore, the lightpath will be shared by several connections traveling from multiple ingress nodes to a single egress node. This technique combines the benefits of optical bypass and the statistical multiplexing gain. In order to gauge the value of the proposed solution, we formulate the problem using integer linear programming and study its performance through different scenarios using a prototype network. Our results show that distributed aggregation technique can improve significantly the network throughput and reduce the network cost.

Self-Diagnosis Technique for Virtual Private Networks Combining Bayesian Networks and Case-Based Reasoning

Fault diagnosis is a critical task for operators in the context of e-TOM (enhanced Telecom Operations Map) assurance process. Its purpose is to reduce network maintenance costs and to improve availability, reliability and performance of network services. Although necessary, this operation is complex and requires significant involvement of human expertise. The study of the fundamental properties of fault diagnosis shows that the diagnosis process complexity needs to be addressed using more intelligent and efficient approaches. In this paper, we present a hybrid approach that combines Bayesian networks and case-based reasoning in order to overcome the usual limits of fault diagnosis techniques and to reduce human intervention in this process. The proposed mechanism allows the identification of the root cause with a finer precision and a higher reliability. At the same time, it helps to reduce computation time while taking into account the network dynamicity. Furthermore, a study case is presented to show the feasibility and performance of the proposed approach based on a real-world use case: a virtual private network topology.

Matching fairness and performance by preventive traffic control in optical multiple access networks

We present and evaluate a novel protocol of traffic control that aims at solving the fairness issue typical of shared medium networks such as metropolitan rings. The proposed solution called TCARD (Traffic Control Architecture using Remote Descriptors) is based on a preventive mechanism to grant access to the resource -- i.e. free bandwidth is preserved by a node according to the traffic requirements from the other network nodes. A review of the existing methods used to manage fairness in ring networks is done and points out their inherent problems (performance issues, resource wastage or inadequacy). In contrast, we show how the new protocol addresses the above limitations, notably through a performance evaluation study. The major conclusion is the ability to avoid the degradation in performances and the resource sub-utilization while achieving fairness within the network.

Software-Defined LANs for Interconnected Smart Environment

In this paper, we propose a solution to delegate the control and the management of the network connecting the many devices of a smart environment to a software entity, while keeping end-users in control of what is happening in their networks. For this, we rely on the logical manipulation of all connected devices through device abstraction and network programmability. Applying Software Defined Networking (SDN) principles, we propose a software-based solution that we call Software-Defined LANs in order to interconnect devices of smart environments according to the services the users are requesting or expecting.We define the adequate virtualization framework based on Virtual Objects and Communities of Virtual Objects. Using these virtual entities, we apply the SDN architectural principles to define a generic architecture that can be applied to any smart environment. Then we describe a prototype implementing these concepts in the home networking context, through a scenario in which users of two different homes can easily interconnect two private but shareable DLNA devices in a dedicated video-delivery SD-LAN. Finally we provide a discussion of the benefits and challenges of our approach regarding the generalization of SDN principles, autonomic features, Internet of Things scalability, security and privacy aspects enabled by SD-LANs intrinsic properties.

Operator-driven framework for establishing and unifying autonomic network and service management solutions

It is commonly recognized that the technology progress, dynamism but also complexity of telecommunication networks and services increase with rapid paces. Such challenges cannot be efficiently handled by traditional networking and management schemes. Autonomics in network and services management appear as the most viable way out. However, despite the significant research efforts and achievements in this field, a few and only recently start to convince operators for their deployability. In this direction, UniverSelf is a research initiative which proposes a pragmatic solution for overcoming the increasing complexity a) by consolidating and capitalizing on lessons learnt and b) by identifying and solving actual, first-priority, immediate and mid-term manageability problems encountered by operators. The cornerstone of UniverSelf approach is the Unified Management Framework (UMF), an operator-driven framework that designates processes, tools and methods for establishing (legacy, emerging and yet undiscovered) autonomic solutions in the joint management of networks and services. This paper provides a first concise description of the UMF design in terms of core, reusable and cohesive functional blocks and interfaces, as derives from the elaboration of requirements elicited from a set of operator problems (use cases). The design is complemented by principles and goals that address important high-level challenges such as the unification/federation of diverse autonomic solutions and technology domains, the governance of autonomic infrastructures and services, as well as the embodiment of autonomic solutions (intelligence) into the management ecosystem.

Core functional and network empower mechanisms of an operator-driven, framework for unifying autonomic network and service management

Future Internet (FI) constitutes a complex and dynamic environment, the requirements of which cannot be adrressed by traditional management schemes. The alternative is the approach of autonomic network and service management. In this context, the UniverSelf research project proposes a promising solution, called Unified Management Framework (UMF), which targets the unification of autonomic network and service management. UMF addresses FI challenges by exploiting governance of automatically managed infrastructures and services, unification of diverse autonomic solutions, and adaptation to rapidly changing environment with respect to managed system properties and service and users requirements. Accordingly, this paper presents the UMF core blocks, namely Governance, Coordination and Knowledge blocks, including a description of their underlying mechanisms. The paper also describes the Network Empowerment Mechanisms (NEM) that empower networks with autonomic algorithms/solutions and can be embedded into existing and future systems in a “plug and play” way.

Identifying standardization opportunities of an operator-driven, framework for unifying autonomic network and service management

The increasing dynamism, complexity and challenges of networks and services cannot be handled by traditional management schemes. The alternative is the approach of autonomic network and service management. In this context, the UniverSelf research project proposes a promising solution, called Unified Management Framework (UMF) with the goal to unify and establish autonomics in the management of networks and services. UMF provides the processes, tools and methods for achieving unification of diverse autonomic solutions, governance of automatically managed infrastructures and services, and “plug and play” of autonomic solutions within existing and future management ecosystems. Despite the soundness of UMF vision from the research point of view, careful and well planned roadmap towards standardization is required in order to boost its deployability and operator adoption. Accordingly, this paper first describes the approach followed for the design of UMF and the set of functional blocks derived as an outcome of this approach. Based on the elaboration and evolution of these functional blocks, the focus is then placed on three components namely, governance, knowledge, coordination, which comprise the so called UMF core and will monopolize the effort towards deriving the upcoming releases of UMF. The standardization opportunities of UMF can be actually indentified while looking into these components and their associated interfaces.