Showing papers in "Journal of Network and Systems Management in 2009"

A Survey on One-Hop Clustering Algorithms in Mobile Ad Hoc Networks

Abstract: Clustering in mobile ad hoc network (MANET) play a vital role in improving its basic network performance parameters like routing delay, bandwidth consumption and throughput. One-hop clustering scheme adopts the simple mechanism to make the logical partition of the dynamic network where the network topology changes constantly resulting an unstable clustering. This paper makes a comprehensive survey of some bench-mark one-hop clustering algorithms to understand the research trends in this area. The literature provides the logic of cluster formation for different algorithms in achieving a linked cluster architecture and an intensive simulation survey of their performance on the cluster maintenance aspects such as cluster density, frequency of cluster reelection, frequency of cluster changes by the nodes and the granularity of cluster heads. This paper should facilitate the researchers as well as practitioners in choosing a suitable clustering algorithm on the basis of their formation and maintenance overhead, before any routing scheme is adopted in the mobile ad hoc network.

Ontology-Based Network Management: Study Cases and Lessons Learned

Abstract: Ontology based network management has recently evolved from a theoretical proposal to a more mature technology. As such, it is now being applied in many research projects in a number of different network management and security scenarios. This application has enabled the validation of the main ideas of the proposals and to learn some of the problems that it brings. This paper describes several research projects where ontology based network management proposals were applied, detailing the most important facets of the initial proposals that were used and explaining the main advantages and drawbacks that were found after prototyping these proposals.

The Design of a New Policy Model to Support Ontology-Driven Reasoning for Autonomic Networking

Abstract: The purpose of autonomic networking is to manage the business and technical complexity of networked components and systems. However, the lack of a common lingua franca makes it impossible to use vendor-specific network management data to ascertain the state of the network at any given time. Furthermore, the tools used to analyze management data, which include information and data models, ontologies, machine learning algorithms, and policy languages, are all different, and hence require different data in different formats. This paper describes a new version of the Directory Enabled Networks next generation (DEN-ng) policy model, which is part of the FOCALE autonomic network architecture. This new policy model has been built using three guiding principles: (1) the policy model is rooted in information models, so that it can govern managed entities, (2) the model is expressly constructed to facilitate the generation of ontologies, so that reasoning about policies constructed from the model may be done, and (3) the model is expressly constructed so that a policy language can be developed from it.

The Use of Context-Aware Policies and Ontologies to Facilitate Business-Aware Network Management

Abstract: The purpose of autonomic networking is to manage the business and technical complexity of networked components and systems. However, existing network management data has no link to business concepts. This makes it very difficult to ensure that services offered by the network are meeting business objectives. This paper describes a novel context-aware policy model that uses a combination of modeled and ontological data to determine the current context, which policies are applicable to that context, and what services and resources should be offered to which users and applications.

Modeling Semantic Web Services with the Web Service Modeling Toolkit

Abstract: The lack of any methodology for modeling Semantic Web Services means that developers wishing to utilize technologies like the Web Service Modeling Ontology, the Web Service Modeling Language, and the Web Service Execution Environment are lost in a Semantic wilderness with no road signs to guide them on their way This paper presents an initial guide for developers wishing to model Semantic Web Services, along with a description of the Web Service Modeling Toolkit that provides tool support for the activities that must be conducted by the developer in this process

Applying Semantic Techniques to Search and Analyze Bug Tracking Data

Abstract: The Web has become an important knowledge source for resolving system installation problems and for working around software bugs. In particular, web-based bug tracking systems offer large archives of useful troubleshooting advice. However, searching bug tracking systems can be time consuming since generic search engines do not take advantage of the semi-structured knowledge recorded in bug tracking systems. We present work towards a semantics-based bug search system which tries to take advantage of the semi-structured data found in many widely used bug tracking systems. We present a study of bug tracking systems and we describe how to crawl them in order to extract semi-structured data. We describe a unified data model to store bug tracking data. The model has been derived from the analysis of the most popular systems. Finally, we describe how the crawled data can be fed into a semantic search engine to facilitate semantic search.

On Metrics to Distinguish Skype Flows from HTTP Traffic

Abstract: Skype is a Voice over IP (VoIP) Internet application that is gaining huge popularity in recent years. A key point to Skype popularity is its capability to dynamically adapt itself to operate behind firewalls or network proxies. A common way adopted by Skype to delude these network devices is to use port 80, normally expected to comprise HTTP traffic. In this paper, we propose metrics and investigate statistical tests intended to clearly distinguish Skype flows from HTTP traffic. We validate our study using real-world experimental datasets gathered at a commercial Internet Service Provider (ISP). Our experimental results suggest that the proposed methodology may be seen as a promising building block towards a system to detect general protocol anomalies in HTTP traffic.

Use of Ontologies as Representation Support of Workflows Oriented to Administrative Management

Abstract: One of the applications of workflow systems is the management of administrative processes characterized by the transmission of information elements among users of an organization. Tasks contained in these processes are carried out by users responsible for confirming, modifying or adding information throughout. These processes need to be defined in workflow management systems in which all the elements are perfectly identified and are easily adaptable to changes that may arise in the sequences of tasks, in the users involved or in the data transmitted from one task to another. For this kind of processes is easier to reuse those represented in ontologies. On one hand, existing ontologies for representing some domain elements can be reused. At the same time, ontologies have an excellent expressive capacity to define tasks, their relationships and the flow control among them with precision. This paper proposes a complete model, together with the necessary software tools, for tackling this issue.

Using NetFlow/IPFIX for Network Management

Abstract: To exchange experiences with, and to discuss ideas on the usage of NetFlow/IPFIX in network management, the IRTF/NMRG, together with the European EMANICS Network of Excellence, organized a one-day workshop in October 2008. This paper presents a report of that meeting.

Chasing a Definition of Alarm

Abstract: Alarm management has been around for decades in telecom solutions. We have seen various efforts to define standardised alarm interfaces. The research community has focused on various alarms correlation strategies. Still, after years of effort in industry and research alike, network administrators are flooded with alarms; alarms are suffering from poor information quality; and the costs of alarm integration have not decreased. In this paper, we explore the concept of `alarm'. We define `alarm' and alarm-type concepts by investigating the different definitions currently in use in standards and research efforts. Based on statistical alarm data from a mobile operator we argue that operational and capital expenditures would decrease if alarm sources would apply to our alarm model.

Business-Driven Design of Infrastructures for IT Services

Abstract: A methodology for designing data center infrastructure for Information Technology (IT) services is developed. The main departure from existing methodologies is that it evaluates and compares alternative designs using business metrics rather than purely technical metrics. Specifically, the methodology evaluates the business impact (financial loss) imposed by imperfect infrastructure. The methodology provides the optimal infrastructure that minimizes the sum of provisioning costs and business losses incurred during failures and performance degradations. Several full numerical example scenarios are provided and results are analyzed. The use of the method for dynamically provisioning an adaptive infrastructure is briefly discussed.

From IMS Management to SOA Based NGN Management

Abstract: Although IP Multimedia Subsystem (IMS) based Next Generation Networks (NGNs) are already emerging as the common session control platform for converging fixed, mobile and cable networks, harmonized solutions for the management of these converged platforms have still got to be developed. This document describes a hands-on approach to NGN Management. Started with IMS specific management systems, succeeding research had to take into account the importance of the management of NGN SDPs as well. This work shows that the hybrid nature of an NGN, where services can be delivered at the IMS layer, by SIP signaling mechanisms, as well as at the SDP, via Web Services, requires a harmonized management approach. Taking into account Service Oriented Architecture (SOA) principles and policy based model driven architectures, this work shows that a unification of service composition and service management already at the workflow creation level, bares significant benefits in terms of automation and harmonization. Following the SOA paradigm, the approach presented here does not differentiate between business process management (BPM) and management process management. Focusing on Telemanagement Forum's enhanced Telecom Operations Map service fulfillment and service assurance operations, this document describes an New Generation Software and Services (NGOSS) based implementation of a unified Operation Support System (OSS) for NGNs that encompasses many problems of former stovepipe management solutions in terms of automation, flexibility and manageability.

SLA Design and Service Provisioning for Outsourced Services

Abstract: In this work, a business-driven approach to designing Service Level Agreements in an e-commerce environment is proposed. In contrast to conventional SLA design approaches, the one proposed better captures the relationship between service provider and service client by considering the negative business impact (business loss) originated from IT infrastructure failures and performance degradation and introduces such knowledge into the SLA itself. A complete example scenario shows the value of the proposed approach. A main conclusion is that the SLA established using the business-driven perspective is superior to the one based on a conventional approach since both service provider and client can simultaneously obtain higher profit.

Challenges for Next Generation Network Operations and Service Management: a Report on APNOMS 2008

Abstract: This article presents a report on APNOMS 2008, which was held October 22---24, 2008 in Beijing, China. The theme of APNOMS 2008 was "Challenges for Next Generation Network Operations and Service Management."

A Strategic Approach for Re-organizing the Internet Topology by Applying Social Behavior Dynamics

Abstract: Recent studies have described the topologies of various networks including the Internet are categorized as scale-free networks. Scale-free network is extremely vulnerable to node attacks. However, the suitability of the topology of the Internet for communications has not been studied. We investigate whether the current Internet is optimized in both aspects of communication efficiency and attack tolerance. For this, we define three metrics to represent the capabilities of the network, which are Clustering coefficient, Efficiency, and Reachability. As a result, we found that the value of ?, a scaling exponent in power law function representing the degree distribution of a scale-free network, may be reduced in the present Internet. To reduce the value of ?, we propose four strategies for re-organizing a network. However, in real network, we cannot control the user's preference directly. We use a diffusion model based on social behavior dynamics. Furthermore, we show the characteristics of the re-organized networks, and discuss which strategy is more appropriate for achieving a desired network.

Design of Common Resource Management and Network Simulator in Heterogeneous Radio Access Network Environment

Abstract: By the newly emerging radio access technologies, we face the new heterogeneous network environment. Focusing on the co-existence of multiple access networks and the complex service combinations, the wireless service operators should guarantee good quality of services for every user. Thus, the service operators build a new operation framework which combines the existing networks and newly adopted ones. Our objective is finding the optimal heterogeneous network operation framework. We suggest the market-based marginal cost function for evaluating the relative value of resources for each network and develop a whole new heterogeneous network operation framework. To prove the applicability of the proposed operation framework, we build a large-scale JAVA simulator. We can easily test the various service scenarios in heterogeneous network environment by the simulator.

Managing Networks and Services of the Future

Abstract: Today, we see several emerging environments, with a large diversity of devices, networks, providers and service domains, characterized as the networks and services of the future. This special issue contains four papers on how to manage important topics of these environments: policy model to support ontology-driven reasoning for autonomic computing, SOA-based NGM management, metrics to distinguish application traffic, and SLA design and service provisioning for outsourced services.

A Snapshot of Ontological Approaches for Network and Service Management

Abstract: In our threshold article for this journal back in early 2007 (Volume 15, Number 1), we stated: Network resources will always be heterogeneous, and thus have different functionalities and programming models. The standardisation of the Resource Description Framework (RDF) and the Web Ontology Language (OWL) by the World Wide Web Consortium’s Semantic Web initiative has provided the representational stability and an expanding toolset that in turn has motivated the increasing adoption of ontology languages in management systems. Given that increasing interest of the network and system management community in applying ontology-based semantics to the development and operation of management systems, it was considered timely to explore the diversity and vibrancy of the activity through a special issue call. In choosing the articles for this special issue, we have attempted to represent through our selection the spread of activity, from innovative research through engineering approaches through reports of experience. We have also shown the profound influence of ontology-based management through the diversity of application areas, including network management, service management, and service engineering.

Operations Research Methods for Autonomic Resource Management

Abstract: Varying service demands on next generation networks requires autonomic resource management capabilities to ensure service delivery to customers, motivating the need to develop self-managing algorithms for this purpose. In this paper, we use algorithms from the Operations Research community for this purpose. First, we adapt the Transportation Model to manage distributed resources in the next generation network infrastructure. Coupled with monitoring capabilities, the proposed scheme can automatically adjust the virtual resource allocation to optimize the costs incurred by service providers in offering services to customers. Second, we propose the use of Inventory Control to predict needs for virtual resources and to pre-order required virtual resource amounts. We compare two possible Inventory Control models to manage the virtual resources involved in service delivery. We perform extensive simulations to show the performance improvements made possible by the use of the Transportation Model and Inventory Control for autonomic resource management in next generation networks.

Adaptive Performance Management for SMS Systems

Abstract: We present a design for performance management of SMS systems. The design takes as input the administrator's performance objectives, which can be adjusted at run-time. Based on these objectives, the design takes the necessary actions to achieve them and it dynamically adapts to changing networking conditions. It does so by periodically solving a linear optimization problem that computes a new configuration for the SMS system. We have evaluated the design through extensive simulations in various scenarios using traces from a production SMS system. It has proved effective in achieving the administrator's performance objectives, and efficient in terms of computational cost. Our experiments also show that the design is adaptive, i.e., it effectively adapts the systems's configuration to changes in the networking conditions, in order to continuously meet the performance objectives. Finally, the feasibility of our design is proved through the development of a prototype on a commercial SMS platform.

Standards and New Technology for Systems and Virtualization Management: A Report on SVM'08

Abstract: Intended as a forum for active discussions and the foundation of new cooperations, the second international workshop on Systems and Virtualization Management (SVM’08) was held at the Leibniz Supercomputing Centre (LRZ) in Garching n. Munich, Germany, on October 21st/22nd, 2008. It was jointly organized by the Distributed Management Task Force (DMTF, see http://www.dmtf.org), which is an industry organization leading the development of management standards for enterprise environments, and the Munich Network Management Team (MNMTeam, see http://www.mnm-team.org), which is a group of researchers from the Munich universities as well as the LRZ that has been established more than 20 years ago and focuses on integrated network, systems, and security management. Systems management has recently seen growing interest in virtualization technology and the need to manage the virtualization of servers, storage, and network resources. The goal of SVM’08 was to illuminate related standards and research issues, covering areas such as:

On the Performance and Scalability of Web Services for Monitoring MPLS-based Networks

Abstract: Web Services is an XML-based technology that has attracted significant attention for building distributed Internet services. Considerable research efforts have been trying to extend it to become a unifying management technology; initial evaluation efforts have demonstrated promising application potential in the domain of network and service management. This paper analyzes the monitoring requirements of a management system used in architectures for providing quality of service, and shows how Web Services can be used effectively to fulfill these requirements. In order to achieve this, a WS-based framework was designed and a query tool was developed to support distributed, optimized retrieval of management information exposed as Web Services. The query tool supports selective and bulk retrieval from MPLS-capable routers. Management information retrieval is demonstrated through three monitoring scenarios, and the measured performance in terms of latency and bandwidth is compared against a conventional approach based on SNMP.

A Closed-Loop Control Traffic Engineering System for the Dynamic Load Balancing of Inter-AS Traffic

Abstract: Inter-AS outbound traffic engineering (TE) is a set of techniques for controlling inter-AS traffic exiting an autonomous system (AS) by assigning the traffic to the best egress points (i.e. routers or links) from which the traffic is forwarded to adjacent ASes towards the destinations. In practice, changing network conditions such as inter-AS traffic demand variation, link failures and inter-AS routing changes occur dynamically. These changes can make fixed outbound TE solutions inadequate and may subsequently cause inter-AS links to become congested. In order to overcome this problem, we propose the deployment of a closed-loop control traffic engineering system that makes outbound traffic robust to inter-AS link failures and adaptive to changing network conditions. The objective is to keep the inter-AS link utilization balanced under unexpected events while reducing service disruptions and reconfiguration overheads. Our evaluation results show that the proposed system can successfully achieve better load balancing with less service disruption and re-configuration overhead in comparison to alternative approaches.

A Multiagent Platform for Ubiquitous Service Provision

Abstract: The Virtual Home Environment is very important in contemporary mobile telecommunications infrastructure as it caters for the ubiquitous provision of services irrespective of network, location and user device. The universality of systems like Universal Mobile Telecommunications System and wi-fi increases the need for the rapid introduction of efficient VHE schemes. In this paper, we study the adoption of Mobile Agents for handling the VHE functionality. Mobile agents are nicely harmonized with the broader idea of VHE as they allow the autonomous execution of tasks by components that roam from node to node and network to network. We present the detailed modeling of a VHE provisioning architecture and investigate its suitability for different use cases and technical options (e.g., end user devices). The adoption of mobile agents for the ubiquitous provision of telecommunication services is quite promising in terms of efficiency. Through a series of experiments we quantify the performance benefits stemming from the adoption of mobile agents in contrast to conventional service provisioning schemes.