Lisandro Zambenedetti Granville

Data Center Network Virtualization: A Survey

With the growth of data volumes and variety of Internet applications, data centers (DCs) have become an efficient and promising infrastructure for supporting data storage, and providing the platform for the deployment of diversified network services and applications (e.g., video streaming, cloud computing). These applications and services often impose multifarious resource demands (storage, compute power, bandwidth, latency) on the underlying infrastructure. Existing data center architectures lack the flexibility to effectively support these applications, which results in poor support of QoS, deployability, manageability, and defence against security attacks. Data center network virtualization is a promising solution to address these problems. Virtualized data centers are envisioned to provide better management flexibility, lower cost, scalability, better resources utilization, and energy efficiency. In this paper, we present a survey of the current state-of-the-art in data center networks virtualization, and provide a detailed comparison of the surveyed proposals. We discuss the key research challenges for future research and point out some potential directions for tackling the problems related to data center design.

Software-defined networking: management requirements and challenges

SDN is an emerging paradigm currently evidenced as a new driving force in the general area of computer networks. Many investigations have been carried out in the last few years about the benefits and drawbacks in adopting SDN. However, there are few discussions on how to manage networks based on this new paradigm. This article contributes to this discussion by identifying some of the main management requirements of SDN. Moreover, we describe current proposals and highlight major challenges that need to be addressed to allow wide adoption of the paradigm and related technology.

Distributed autonomic resource management for network virtualization

Network virtualization is an emerging trend claimed to reduce the costs of future networks. The key strategy in network virtualization is of slicing physical resources (links, routers, servers, etc.) to create virtual networks composed of subsets of these slices. One important challenge on network virtualization is the resource management of the physical or substrate networks. Sophisticated management techniques should be used to accomplish such management. The sophisticated techniques offered by autonomic communications rise as an appropriated alternative to address the challenges of managing the efficient use of substrate resources on network virtualization. Thus, this paper proposes a distributed self-organizing model to manage the substrate network resources. An evaluation scenario is depicted and simulations show that approximately 36.8% of the network traffic load can be spared when the self-organizing model is enabled in the evaluated scenario.

Implementation and bandwidth consumption evaluation of SNMP to Web services gateways

Web services gateways are needed to include SNMP devices into a Web services based management architecture. We propose in this paper two approaches for such gateways and evaluate these approaches in order to verify the feasibility of using Web services closer to the network devices interface. We primarily tested the bandwidth consumed by these gateways when using SOAP with HTTP, HTTPS, and a compression process. The evaluation shows that Web services gateways are especially interesting when the number of SNMP object instances retrieved is high.

Internet of Things in healthcare: Interoperatibility and security issues

Internet of Things devices being used now expose limitations that prevent their proper use in healthcare systems. Interoperability and security are especially impacted by such limitations. In this paper, we discuss todays issues, including benefits and difficulties, as well as approaches to circumvent the problems of employing and integrating Internet of Things devices in healthcare systems. We present this discussion in the context of the REMOA project, which targets a solution for home care/telemonitoring for patients with chronic illnesses.

Booters — An analysis of DDoS-as-a-service attacks

In 2012, the Dutch National Research and Education Network, SURFnet, observed a multitude of Distributed Denial of Service (DDoS) attacks against educational institutions. These attacks were effective enough to cause the online exams of hundreds of students to be cancelled. Surprisingly, these attacks were purchased by students from Web sites, known as Booters. These sites provide DDoS attacks as a paid service (DDoS-as-a-Service) at costs starting from 1 USD. Since this problem was first identified by SURFnet, Booters have been used repeatedly to perform attacks on schools in SURFnets constituency. Very little is known, however, about the characteristics of Booters, and particularly how their attacks are structure. This is vital information needed to mitigate these attacks. In this paper we analyse the characteristics of 14 distinct Booters based on more than 250 GB of network data from real attacks. Our findings show that Booters pose a real threat that should not be underestimated, especially since our analysis suggests that they can easily increase their firepower based on their current infrastructure.

Resource sharing in heterogeneous cloud radio access networks

Heterogeneous cloud radio access networks incorporate the heterogeneous network and cloud radio access network concepts for next generation cellular networks. H-CRANs exploit the heterogeneity of macro and small cells from HetNets, enabling cellular networks to achieve higher spectral efficiency. Meanwhile, concepts from C-RANs involving baseband units and remote radio heads enable H-CRANs to insert a centralized point of processing for cellular networks, reducing capital and operational expenditures. In this article, we investigate resource sharing in H-CRANs at three levels: spectrum, infrastructure, and network. For each level, we discuss the benefits and challenges, highlighting key enabling technologies that make resource sharing feasible in H-CRANs, such as software defined radio, virtualization, network function virtualization, and software defined networking. Through these technologies, H-CRANs can be virtualized in an overlay network capable of achieving enhanced infrastructure and spectrum sharing.

A framework for risk assessment based on analysis of historical information of workflow execution in IT systems

Services provided by modern organizations are usually designed, deployed, and supported by large-scale IT infrastructures. In order to obtain the best performance out of these services, it is essential that organizations enforce rational practices for the management of the resources that compose their infrastructures. A common point in most guides and libraries of best practices for IT management - such as ITIL or COBIT - is the explicit concern with the risks related to IT activities. Proactively dealing with adverse and favorable events that may arise during everyday operations might prevent, for example: delay on deployment of services, cost overrun in activities, predictable failures of handled resources, and, consequently, waste of money. Although important, risk management in practice usually lacks in automation and standardization in IT environments. Therefore, in this article, we introduce a framework to support the automation of some key steps of risk management. Our goal is to organize risk information related to IT activities providing support for decision making thus turning risk response planning simpler, faster, and more accurate. The proposed framework is targeted to workflow-based IT management systems. The fundamental approach is to learn from problems reported in the history of previously conducted workflows in order to estimate risks for future executions. We evaluated the applicability of the framework in two case studies both in IT related areas, namely: IT change management and IT project management. The results show how the framework is not only useful to speed up the risk assessment process, but also to assist the decision making of project managers and IT operators by organizing risk detailed information in a comprehensive way.

Distributed Reallocation Scheme for Virtual Network Resources

Network virtualization is an emerging technology for cost-effective sharing of network resources. The key strategy in network virtualization is of slicing physical resources (links, CPU, memory, and storage) to create virtual networks that are assigned to different operators. One important challenge on network virtualization is the efficient use of the physical resources. To accomplish such efficient use the management of the physical resources should be transparent to the applications running within the virtual networks, and should be executed at runtime in order to deal with the variation on the load requests of different virtual networks. Traditional resource allocation schemes use offline, centralized, and global view strategies to manage the use of physical resources. In contrast to these strategies, we propose a runtime, distributed, local view approach to manage physical resources. In this paper we introduce a virtual network architecture and an associated self-organizing algorithm to reallocate virtual network resources along different physical nodes in order to equalize the bandwidth, and storage consumption on the physical nodes. We developed a virtual network model based on Omnet++ to simulate the designed self-organizing algorithm. An IPTV testbed scenario is presented and initial experiments, about the interruption time of the application inside the IPTV virtual network, are described.

Interactive monitoring, visualization, and configuration of OpenFlow-based SDN

Software-Defined Networking (SDN) is an emerging paradigm that arguably facilitates network innovation and simplifies network management. However, in the context of SDN, management activities, such as monitoring, visualization, and configuration can be considerably different from traditional networks. An SDN controller, for example, can be customized by network administrators according to their needs. Such customizations might pose an impact on resource consumption and traffic forwarding performance, which is difficult to assess without an SDN-devoted management system. In this paper, we initially present an analysis of control traffic in SDN aiming to better understand the impact of the communication between the controller and forwarding devices. Afterwards, we propose an interactive approach to SDN management through monitoring, visualization, and configuration that includes the administrator in the management loop. To show the feasibility of our approach a prototype has been developed. The results obtained with this prototype show that our approach can help the administrator to better understand the impact of configuring SDN-related parameters on the overall network performance.