Liane Margarida Rockenbach Tarouco

Managing computer networks using peer-to-peer technologies

Peer-to-peer systems and network management are usually related to each other because the traffic loads of P2P systems have to be controlled to avoid regular network services becoming unavailable due to network congestion. In this context, from a network operation point of view, P2P systems often mean problems. In this article we take a different perspective and look at P2P technologies as an alternative to improve current network management solutions. We introduce an approach where P2P networks are used as flexible interdomain distributed management systems able to provide facilities often absent in traditional management systems. We present three examples of P2P-based network management: how managed network views can be shared in a P2P network, how P2P-based application layer routing can improve connectivity between management entities, and how groups of peers can be used to process management tasks in a balanced way. Our main goal is to show that P2P technologies are a feasible tool for network management, and thus motivate further investigations on the subject.

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.

Comparing Web services with SNMP in a management by delegation environment

The traditional management by delegation model has lead the IETF, more recently, to define its Script MIB, which allows management entities to transfer, control and retrieve results generated by management scripts. These operations, however, can also be accomplished by Web services. Web services have been pointed out as an interesting approach for network management in general, but in this paper we present the use of Web services in the specific context of management by delegation. We also present a Web services-based system prototype that allows us to compare a Script MIB implementation against SNMP to Web service gateways for management by delegation.

Troubleshooting network faults using past experience

So far, trouble ticket systems have been used to store information concerned with network faults. An interesting approach is the development of an expert system that takes into account the knowledge accumulated by these systems in order to propose solutions for a new problem. This work presents DUMBO, a system that applies the case-based reasoning paradigm to a trouble ticket system in order to aid the diagnosis of computer network problems. One important aspect of DUMBO is that it performs continuous learning, i.e., the knowledge base is increased by the incorporation of new solved cases in a way such that other similar cases can be proposed as solutions to a current new problem. Another important aspect is the use of production rules in some specific tasks of the reasoning processes. This work also describes typical domain problems, the system architecture, the experiments and practical results reached with the developed prototype and its current state.

Evaluating the Performance of SNMP and Web Services Notifications

Web services against SNMP comparisons have been carried out by the network management community in order to understand the impact on adopting Web services as a management tool. In these comparisons, however, notification messages have been neglected to a secondary plane in such a way that the current conclusions about the performance of Web services may not apply for networks extensively managed via notifications. In this paper we first evaluate the performance of Web services notifications encoded following the WS-notification specification, and compare it with the performance of SNMP traps. Then, we introduce a configurable SNMP to Web services gateway that reacts to SNMP traps on behalf of an SNMP manager, retrieves further information from the notifying entity, and builds up WS-notification compliant messages which are sent to Web services-based managers. We finally evaluate the performance of the proposed solution in order to redraw the current conclusions about Web services against SNMP, now explicitly considering the also important notification support

An hierarchical policy-based architecture for integrated management of grids and networks

The management of the underlying network infrastructure, which supports the grid communications, is not proceeded through the same management systems used for the grid management. In this scenario, an integrated management of grids and networks could turn the maintenance processes easier. This paper proposes an hierarchical policy-based architecture, whose goal is to allow such desired integration, where grid policies are translated to network policies following mapping rules defined by network administrators. It also describes a prototype implemented based on the architecture.

Substituting COPS-PR: an evaluation of NETCONF and SOAP for policy provisioning

The COPS-PR protocol has been defined by the IETF to provide policy provisioning in networks managed through the policy-based network management approach. Although some network players already ship their devices with proper COPS-PR support, there is a trend in the industry and in the IETF of discontinuing COPS-PR as a policy protocol. Meanwhile, two other protocols, namely NETCONF and SOAP, have been seriously considered in the network management field. This paper proposes and evaluates both NETCONF and SOAP as substitutes for COPS-PR, presenting how these protocols can be used for policy provisioning. The performance evaluation of NETCONF and SOAP against COPS-PR addresses two main aspects: network usage as a result of protocol overhead, and protocol delay as a result of protocol message processing. This study shows that both NETCONF and SOAP are interesting and feasible replacements for COPS-PR, but require appropriate modeling when deployed in networks

A cloud monitoring framework for self-configured monitoring slices based on multiple tools

The monitoring of cloud computing environments is a key point to assure the availability of the cloud slices offered to cloud users. However, there are not any monitoring systems that satisfy all the cloud administrator requirements which imposes that cloud slices need to be monitored by a set of monitoring systems. The set of monitoring system configuration necessary to monitor a cloud slice and the corresponding set of monitored metrics we define as a monitoring slice. Unfortunately, the monitoring slices need to be built using solutions that are not integrated with cloud platforms. This lack of integration imposes that cloud administrators manually configure the monitoring solutions or develop scripts to automate this task. In this paper we propose a framework to address the problem of creating monitoring slices automatically independent of the monitoring solutions employed. To evaluate our proposed framework in an IaaS scenario, we develop FlexACMS, flexible automate cloud monitoring slices, which relies on a modules that flexibly handles cloud platforms and monitoring solutions.

Objetos de Aprendizagem: Uma comparação entre SCORM e IMS Learning Design

Diversas Tecnologias da Informacao e Comunicacao (TICs) tem sido discutidas com vistas a sua utilizacao na Educacao. O professor, antes com poucos recursos tecnologicos a sua disposicao, hoje dispoe de um amplo leque de possibilidades e cabe a ele decidir a melhor maneira de aplica-las. Neste sentido a tecnologia de Objetos de Aprendizagem com suas diversas utilizacoes tem se mostrado uma alternativa bastante interessante. Modelos e padroes como o SCORM e Learning Design entre outros, tem cada vez mais angariado adeptos ao redor do mundo. Apesar de terem os Objetos de Aprendizagem como seu foco principal, os dois modelos se diferem bastante em sua estrutura. Enquanto o SCORM foca mais na interacao individual entre o aluno e o conteudo instrucional, o IMS Learning Design se volta para toda a atividade de aprendizagem. O objetivo deste artigo e analisar os dois modelos sob o ponto de vista de ferramentas de auxilio ao professor no processo de ensino-aprendizagem.

An Evaluation of Service Composition Technologies Applied to Network Management

Service composition is a technique that may help the development of management systems by aggregating smaller services to produce more sophisticated ones. Service composition can be realized by using traditional management technologies, although these technologies have not been conceived taking composition support as one of their main aspects. Current service-oriented architecture (SOA)-related efforts, however, define specific standards for Web services composition, such as the Web services business process execution language (WS-BPEL). Web services for network management have been investigated by the management community at least in the last four years, but up to today no research evaluating Web services composition applied to network management has been carried out. In this paper we present such an evaluation where compositions based on the IETF Script MIB, ad-hoc Java Web services, and WS- BPEL are compared against one another in a managed network where BGP routers are investigated in order to identify route advertisement anomalies.