112 research outputs found
A trustworthy mobile agent infrastructure for network management
Despite several advantages inherent in mobile-agent-based approaches to network management as compared to traditional SNMP-based approaches, industry is reluctant to adopt the mobile agent paradigm as a replacement for the existing manager-agent model; the management community requires an evolutionary, rather than a revolutionary, use of mobile agents. Furthermore, security for distributed management is a major concern; agent-based management systems inherit the security risks of mobile agents. We have developed a Java-based mobile agent infrastructure for network management that enables the safe integration of mobile agents with the SNMP protocol. The security of the system has been evaluated under agent to agent-platform and agent to agent attacks and has proved trustworthy in the performance of network management tasks
A web services based framework for efficient monitoring and event reporting.
Network and Service Management (NSM) is a research discipline with significant research contributions the last 25 years. Despite the numerous standardised solutions that have been proposed for NSM, the quest for an "all encompassing technology" still continues. A new technology introduced lately to address NSM problems is Web Services (WS). Despite the research effort put into WS and their potential for addressing NSM objectives, there are efficiency, interoperability, etc issues that need to be solved before using WS for NSM. This thesis looks at two techniques to increase the efficiency of WS management applications so that the latter can be used for efficient monitoring and event reporting. The first is a query tool we built that can be used for efficient retrieval of management state data close to the devices where they are hosted. The second technique is policies used to delegate a number of tasks from a manager to an agent to make WS-based event reporting systems more efficient. We tested the performance of these mechanisms by incorporating them in a custom monitoring and event reporting framework and supporting systems we have built, against other similar mechanisms (XPath) that have been proposed for the same tasks, as well as previous technologies such as SNMP. Through these tests we have shown that these mechanisms are capable of allowing us to use WS efficiently in various monitoring and event reporting scenarios. Having shown the potential of our techniques we also present the design and implementation challenges for building a GUI tool to support and enhance the above systems with extra capabilities. In summary, we expect that other problems WS face will be solved in the near future, making WS a capable platform for it to be used for NSM
Towards Automated Network Configuration Management
Modern networks are designed to satisfy a wide variety of competing goals related to network operation requirements such as reachability, security, performance, reliability and availability. These high level goals are realized through a complex chain of low level configuration commands performed on network devices.
As networks become larger, more complex and more heterogeneous, human errors become the most significant threat to network operation and the main cause of network outage. In addition, the gap between high-level requirements and low-level configuration data is continuously increasing and difficult to close. Although many solutions have been introduced to reduce the complexity of configuration management, network changes, in most cases, are still manually performed via low--level command line interfaces (CLIs). The Internet Engineering Task Force (IETF) has introduced NETwork CONFiguration (NETCONF) protocol along with its associated data--modeling language, YANG, that significantly reduce network configuration complexity. However, NETCONF is limited to the interaction between managers and agents, and it has weak support for compliance to high-level management functionalities.
We design and develop a network configuration management system called AutoConf that addresses the aforementioned problems. AutoConf is a distributed system that manages, validates, and automates the configuration of IP networks. We propose a new framework to augment NETCONF/YANG framework. This framework includes a Configuration Semantic Model (CSM), which provides a formal representation of domain knowledge needed to deploy a successful management system. Along with CSM, we develop a domain--specific language called Structured Configuration language to specify configuration tasks as well as high--level requirements. CSM/SCL together with NETCONF/YANG makes a powerful management system that supports network--wide configuration. AutoConf supports two levels of verifications: consistency verification and behavioral verification. We apply a set of logical formalizations to verifying the consistency and dependency of configuration parameters. In behavioral verification, we present a set of formal models and algorithms based on Binary Decision Diagram (BDD) to capture the behaviors of forwarding control lists that are deployed in firewalls, routers, and NAT devices. We also adopt an enhanced version of Dyna-Q algorithm to support dynamic adaptation of network configuration in response to changes occurred during network operation. This adaptation approach maintains a coherent relationship between high level requirements and low level device configuration.
We evaluate AutoConf by running several configuration scenarios such as interface configuration, RIP configuration, OSPF configuration and MPLS configuration. We also evaluate AutoConf by running several simulation models to demonstrate the effectiveness and the scalability of handling large-scale networks
Distributed control of reconfigurable mobile network agents for resource coordination
Includes abstract.Includes bibliographical references.Considering the tremendous growth of internet applications and network resource federation proposed towards future open access network (FOAN), the need to analyze the robustness of the classical signalling mechanisms across multiple network operators cannot be over-emphasized. It is envisaged, there will be additional challenges in meeting the bandwidth requirements and network management...The first objective of this project is to describe the networking environment based on the support for heterogeneity of network components..
A Generic Network and System Management Framework
Networks and distributed systems have formed the basis of an ongoing communications revolution
that has led to the genesis of a wide variety of services. The constantly increasing size and
complexity of these systems does not come without problems. In some organisations, the
deployment of Information Technology has reached a state where the benefits from downsizing and
rightsizing by adding new services are undermined by the effort required to keep the system
running.
Management of networks and distributed systems in general has a straightforward goal: to provide
a productive environment in which work can be performed effectively. The work required for
management should be a small fraction of the total effort. Most IT systems are still managed in an
ad hoc style without any carefully elaborated plan. In such an environment the success of
management decisions depends totally on the qualification and knowledge of the administrator.
The thesis provides an analysis of the state of the art in the area of Network and System
Management and identifies the key requirements that must be addressed for the provisioning of
Integrated Management Services. These include the integration of the different management related
aspects (i.e. integration of heterogeneous Network, System and Service Management).
The thesis then proposes a new framework, INSMware, for the provision of Management Services.
It provides a fundamental basis for the realisation of a new approach to Network and System
Management. It is argued that Management Systems can be derived from a set of pre-fabricated
and reusable Building Blocks that break up the required functionality into a number of separate
entities rather than being developed from scratch. It proposes a high-level logical model in order to
accommodate the range of requirements and environments applicable to Integrated Network and
System Management that can be used as a reference model.
A development methodology is introduced that reflects principles of the proposed approach, and
provides guidelines to structure the analysis, design and implementation phases of a management
system. The INSMware approach can further be combined with the componentware paradigm for
the implementation of the management system. Based on these principles, a prototype for the
management of SNMP systems has been implemented using industry standard middleware
technologies. It is argued that development of a management system based on Componentware
principles can offer a number of benefits. INSMware Components may be re-used and system
solutions will become more modular and thereby easier to construct and maintain
Supporting distributed computation over wide area gigabit networks
The advent of high bandwidth fibre optic links that may be used over very large distances
has lead to much research and development in the field of wide area gigabit networking. One
problem that needs to be addressed is how loosely coupled distributed systems may be built over
these links, allowing many computers worldwide to take part in complex calculations in order
to solve "Grand Challenge" problems. The research conducted as part of this PhD has looked
at the practicality of implementing a communication mechanism proposed by Craig Partridge
called Late-binding Remote Procedure Calls (LbRPC).
LbRPC is intended to export both code and data over the network to remote machines for
evaluation, as opposed to traditional RPC mechanisms that only send parameters to pre-existing
remote procedures. The ability to send code as well as data means that LbRPC requests can
overcome one of the biggest problems in Wide Area Distributed Computer Systems (WADCS):
the fixed latency due to the speed of light. As machines get faster, the fixed multi-millisecond
round trip delay equates to ever increasing numbers of CPU cycles. For a WADCS to be
efficient, programs should minimise the number of network transits they incur. By allowing the
application programmer to export arbitrary code to the remote machine, this may be achieved.
This research has looked at the feasibility of supporting secure exportation of arbitrary
code and data in heterogeneous, loosely coupled, distributed computing environments. It has
investigated techniques for making placement decisions for the code in cases where there are a
large number of widely dispersed remote servers that could be used. The latter has resulted in
the development of a novel prototype LbRPC using multicast IP for implicit placement and a
sequenced, multi-packet saturation multicast transport protocol. These prototypes show that
it is possible to export code and data to multiple remote hosts, thereby removing the need to
perform complex and error prone explicit process placement decisions
Cross-layer multi-cloud real-time application QoS monitoring and benchmarking as-a-service framework
Cloud computing provides on-demand access to affordable hardware (e.g., multi-core CPUs, GPUs, disks, and networking equipment) and software (e.g., databases, application servers and data processing frameworks) platforms with features such as elasticity, pay-per-use, low upfront investment and low time to market. This has led to the proliferation of business criti-cal applications that leverage various cloud platforms. Such applications hosted on sin-gle/multiple cloud platforms have diverse characteristics requiring extensive monitoring and benchmarking mechanisms to ensure run-time Quality of Service (QoS) (e.g., latency and throughput). The process of monitoring and benchmarking cloud applications is as yet a criti-cal issue to be further studied and addressed.
Current monitoring and benchmarking approaches do not provide a holistic view of per-formance QoS for distributed applications cross cloud layers on multi-cloud environments. Furthermore, current monitoring frameworks are limited to monitoring tasks and do not in-corporate benchmarking abilities. In other words, there is no unified framework that com-bines monitoring and benchmarking functionalities. To gain the ability of both monitoring and benchmarking all under one framework will empower the cloud user to gain more in-depth control and awareness of cloud services.
The Thesis identifies and discusses the major research dimensions and design issues relat-ed to developing techniques that can monitor and benchmark an applicationâs components cross-layers on multi-clouds. Furthermore, the thesis discusses to what extent such research dimensions and design issues are handled by current academic research papers as well as by the existing commercial monitoring tools.
Moreover, the Thesis addresses an important research challenge of how to undertake cross-layer cloud monitoring and benchmarking in multi-cloud environments to provide es-sential information for effective cloud applications QoS management. It proposes, develops, implements and validates CLAMBS: Cross-Layer Multi-Cloud Application Monitoring and Benchmarking, as-a-Service Framework. The core contributions made by this thesis are the development of the CLAMBS framework and underlying monitoring and benchmarking tech-niques which are capable of: i) performing QoS monitoring of application components (e.g.
ii
database, web server, application server, etc.) that may be deployed across multiple cloud platforms (e.g. Amazon EC2, and Microsoft Azure); and ii) giving visibility into the QoS of in-dividual application components, which is not supported by current monitoring and bench-marking frameworks. Experiments are conducted on real-world multi-cloud platforms to em-pirically evaluate the framework and the results validate that CLAMBS can effectively monitor and benchmark applications running cross-layers on multi-clouds.
The thesis presents implementation and evaluation details of the proposed CLAMBS framework. It demonstrates the feasibility and scalability of the proposed framework in real-world environments by implementing a proof-of-concept prototype on multi-cloud platforms. Finally, it presents a model for analysing the communication overheads introduced by various components (e.g. agents and manager) of CLAMBS in multi cloud environments
IPv6: a new security challenge
Tese de mestrado em Segurança InformĂĄtica, apresentada Ă Universidade de Lisboa, atravĂ©s da Faculdade de CiĂȘncias, 2011O Protocolo de Internet versĂŁo 6 (IPv6) foi desenvolvido com o intuito de resolver alguns dos problemas nĂŁo endereçados pelo seu antecessor, o Protocolo de Internet versĂŁo 4 (IPv4), nomeadamente questĂ”es relacionadas com segurança e com o espaço de endereçamento disponĂvel. SĂŁo muitos os que na Ășltima dĂ©cada tĂȘm desenvolvido estudos sobre os investimentos necessĂĄrios Ă sua adoção e sobre qual o momento certo para que o mesmo seja adotado por todos os players no mercado. Recentemente, o problema da extinção de endereçamentos pĂșblicos a ser disponibilizado pelas diversas Region Internet registry â RIRs - despertou o conjunto de entidades envolvidas para que se agilizasse o processo de migração do IPv4 para o IPv6. Ao contrĂĄrio do IPv4, esta nova versĂŁo considera a segurança como um objetivo fundamental na sua implementação, nesse sentido Ă© recomendado o uso do protocolo IPsec ao nĂvel da camada de rede. No entanto, e devido Ă imaturidade do protocolo e Ă complexidade que este perĂodo de transição comporta, existem inĂșmeras implicaçÔes de segurança que devem ser consideradas neste perĂodo de migração. O objetivo principal deste trabalho Ă© definir um conjunto de boas prĂĄticas no Ăąmbito da segurança na implementação do IPv6 que possa ser utilizado pelos administradores de redes de dados e pelas equipas de segurança dos diversos players no mercado. Nesta fase de transição, Ă© de todo Ăștil e conveniente contribuir de forma eficiente na interpretação dos pontos fortes deste novo protocolo assim como nas vulnerabilidades a ele associadas.IPv6 was developed to address the exhaustion of IPv4 addresses, but has not yet seen global deployment. Recent trends are now finally changing this picture and IPv6 is expected to take off soon. Contrary to the original, this new version of the Internet Protocol has security as a design goal, for example with its mandatory support for network layer security. However, due to the immaturity of the protocol and the complexity of the transition period, there are several security implications that have to be considered when deploying IPv6. In this project, our goal is to define a set of best practices for IPv6 Security that could be used by IT staff and network administrators within an Internet Service Provider. To this end, an assessment of some of the available security techniques for IPv6 will be made by means of a set of laboratory experiments using real equipment from an Internet Service Provider in Portugal. As the transition for IPv6 seems inevitable this work can help ISPs in understanding the threats that exist in IPv6 networks and some of the prophylactic measures available, by offering recommendations to protect internal as well as customersâ networks
A Survey of Distributed Network and Systems Management Paradigms
Since the mid 1990s, network and systems management has steadily evolved from a centralized paradigm, where all the management processing takes place in a single management station, to distributed paradigms, where management is distributed over a potentially large number of nodes. Some of these paradigms, epitomized by the SNMPv2 and CMIP protocols, have been around for several years, whereas a flurry of new ones, based on mobile code, distributed objects or intelligent agents, only recently emerged. The goal of this survey is to classify all major network and systems management paradigms known to date, in order to help network and systems administrators design a management application. In the first part of the survey, we present a simple typology, based on a single criterion: the organizational model. In this typology, all paradigms are grouped into four types: centralized paradigms, weakly distributed hierarchical paradigms, strongly distributed hierarchical paradigms and cooperative paradigms. In the second part of the survey, we gradually build an enhanced typology, based on four criteria: delegation granularity, semantic richness of the information model, degree of specification of a task, and degree of automation of management. Finally, we show how to use our typologies to select a management paradigm in a given context. KEYWORDS Distributed Network Management, Distributed Systems Management, Integrated Management, Mobile Code, Distributed Objects, Intelligent Agents, Typology
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Operational support systems for satellite communications
The role of satellite communications is changing from providing bandwidth linking network operators interconnections towards providing IP enabled communications to end users. This migration from few high-value routes towards many low-value routes means that integration and automation of processes with terrestrial networks becomes critical in driving down unit costs. Integration and automation is necessary on all planes: user, control and management. In satellite communications, management aspects, underpinned by Operational Support Systems (OSS) have received the least research attention, making this a valuable topic for study. In most areas, OSS for satellite systems are similar to other domains. However there are some notable areas of difference which have been the focus of this research. The eTOM business framework, developed by the TMF, has been used to highlight aspects of OSS unique to satellite. Since satellite capacity represents the highest operational cost of a satellite route, effective management while minimising the overhead traffic is critical. The transmission of IP packets is assumed and the real-time measurement of QoS parameters such as packet delay and loss emerged as the most important differences. A number of approaches to QoS measurement are feasible, however the use of trace packets is most promising especially for high network loads. An experiment compares the results from simulations, mathematical models and from a test network, using Poisson and self-similar traffic flows. The relationship between measurement accuracy and trace packet intensity is explored and the measurement response time to steps in traffic load is estimated. It is discovered that measurement accuracy improves as the queue load increases, in contrast to alternative approaches such as sampling of user packets. The response time to steps depends upon the degree of self-similarity and is generally longer than the times recommended by standards. A pragmatic approach to management of different modes is proposed where the measurement method is changed depending on the load
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