A distributed topology information system for optical networks based on the semantic web

The research networking community has embraced novel network architectures to provide e-Science applications with dedicated connections instead of shared links. IP and optical services converge in these new infrastructures to form hybrid networks. Lightpaths are the services offered to clients in the optical portion of the network. They are chosen because they guarantee the appropriate QoS in terms of bandwidth and latency. NDL-the Network Description Language-is a data model offering users and providers of lightpaths with a common ontology to describe topology information of hybrid optical networks. The strength of NDL is that it supports a wide range of applications, including pathfinding, visualisation and asset management, via the definition of a common data model to exchange network descriptions. Since NDL is based on the Semantic Web techniques, it is straightforward to relate NDL with application-specific ontologies. In this paper we present the current status of the NDL schemas and its use in several applications

Sheaf Semantics for Physically Motivated Network Description with Applications

This paper introduces the notion of event space, a physically motivated mathematical model of distributed non-deterministic concurrent interaction based on Goguen's work on sheaf semantics. It provides unifying compositional semantics suitable for network and protocol description, which we demonstrate by designing a formal language, network resource calculus (NRC), for which we use the event space as a model. We sketch how NRC can be utilized in two application scenarios: specification of information-centric protocols and proof-carrying network description in protocols, that can be used together

Trends in Computer Network Modeling Towards the Future Internet

This article provides a taxonomy of current and past network modeling efforts. In all these efforts over the last few years we see a trend towards not only describing the network, but connected devices as well. This is especially current given the many Future Internet projects, which are combining different models, and resources in order to provide complete virtual infrastructures to users. An important mechanism for managing complexity is the creation of an abstract model, a step which has been undertaken in computer networks too. The fact that more and more devices are network capable, coupled with increasing popularity of the Internet, has made computer networks an important focus area for modeling. The large number of connected devices creates an increasing complexity which must be harnessed to keep the networks functioning. Over the years many different models for computer networks have been proposed, and used for different purposes. While for some time the community has moved away from the need of full topology exchange, this requirement resurfaced for optical networks. Subsequently, research on topology descriptions has seen a rise in the last few years. Many different models have been created and published, yet there is no publication that shows an overview of the different approaches.

Exploring the Virtual Infrastructures as a Service concept with HIPerNET

With the expansion and convergence of communication and computing, dynamic provisioning of customized networking and processing infrastructures, as well as resource virtualization, are appealing concepts and technologies. Therefore, new models and tools are needed to allow users to create, trust and enjoy such on-demand virtual infrastructures within a wide area context. This research report presents the HIPerNET framework that we are designing and developing for creating, managing and controlling virtual infrastructures in the context of high-speed Internet. The key idea of this proposal is the combination of network- and system-virtualization associated with controlled resource reservation to provide fully isolated environments. HIPerNET's motivations and design principles are presented. We then examine specifically how this framework handles the virtual infrastructures, called Virtual Private eXecution Infrastructures (VPXI). To help specifying customized isolated infrastructures, HIPerNET relies on VXDL, a language for VPXI description and modeling which considers end-host resource as well as the virtual network topology interconnecting them, including virtual routers. We exemplify the VPXI specification, allocation and execution using a real large-scale distributed medical application. Experimental results obtained within the Grid'5000 testbed are presented and analyzed

Constraint-Flow Nets: A Model for Building Constraints from Resource Dependencies

The major research in the resource management literature focuses primarily on two complementary sub-problems: (1) specification languages for formulating resource requests and (2) constraint problems modelling allocation and scheduling. Both directions assume the knowledge of the underlying platform architecture and the dependencies it induces on the usage of the various resources. In this paper, we bridge this gap by introducing constraint-flow nets (cfNets). A cfNet is defined by a set of resources and dependencies between them, each dependency having an associated constraint schema. The model is inspired by Petri nets, with resources corresponding to places and dependencies—to transitions. Given an architecture of dependent resources, an initial resource request is propagated through the dependencies. The generated constraints are then conjuncted into the global allocation constraint. We study the notion of conflicts in cfNets and prove that for conflict-free cfNets the global allocation constraint can be constructed unambiguously. Furthermore, we provide an SMT-based algorithm for conflict detection and discuss the use of priorities to dynamically resolve conflicts at run-time. Finally, we illustrate the use of cfNets on a case study inspired by the Kalray MPPA architecture

Modelling Resource Dependencies

The major research in the resource management literature focuses primarily on two directions: 1) specification languages for formulating resource requests and 2) constraint problems modelling allocation and scheduling. Both directions assume the knowledge of the underlying platform architecture and the dependencies it induces on the usage of the various resources. In this report we bridge this gap, by introducing Constraint-Flow Nets (cfNets). A cfNet is defined by a set of resources and dependencies between them, each dependency having an associated constraint. The model is inspired by Petri Nets, with resources corresponding to places and dependencies—to transitions. Given an architecture of dependent resources, an initial resource request is propagated through the dependencies. The generated constraints are then conjuncted into the global allocation constraint. We study the notion of conflicts in cfNets and prove that for conflict-free cfNets the global allocation constraint can be constructed unambiguously. Furthermore, we provide an efficient algorithm for conflict detection

Integration of distributed terminology resources to facilitate subject cross-browsing for library portal systems

With the increase in the number of distributed library information resources, users may have to interact with different user interfaces, learn to switch their mental models between these interfaces, and familiarise themselves with controlled vocabularies used by different resources. For this reason, library professionals have developed library portals to integrate these distributed information resources, and assist end-users in cross-accessing distributed resources via a single access point in their own library. There are two important subject-based services that a library portal system might be able to provide. The first is a federated search service, which refers to a process where a user can input a query to cross-search a number of information resources. The second is a subject cross-browsing service, which can offer a knowledge navigation tree to link subject schemes used by distributed resources. However, the development of subject cross-searching and browsing services has been impeded by the heterogeneity of different KOS (Knowledge Organisation System) used by different information resources. Due to the lack of mappings between different KOS, it is impossible to offer a subject cross-browsing service for a library portal system. [Continues.

Using RDF to describe networks

Conventions such as iGrid 2005 and SuperComputing show that there is increasing demand for more service options on networks. For such networks, large teams of experts are needed to configure and manage them. In order to make the full potential of hybrid networks available to the ordinary user, the complexity must be reduced. This paper presents the idea of the Network Description Language (NDL), which builds on Semantic Web techniques to create a distributed Topology Knowledge Base (TKB). The TKB can provide a collection of reachability graphs, showing connectivity rules among physical and/or virtual entities. Latching onto the Semantic Web provides network management with a new breed of tools—bots, compilers, browsers, both commercial offthe-shelf (COTS) and open source. The approach appears to be applicable to the Global Lambda Integrated Facility (GLIF) as well as otherexperimental communities

Using RDF to describe networks www.elsevier.com/locate/fgcs

Conventions such as iGrid 2005 and SuperComputing show that there is increasing demand for more service options on networks. For such networks, large teams of experts are needed to configure and manage them. In order to make the full potential of hybrid networks available to the ordinary user, the complexity must be reduced. This paper presents the idea of the Network Description Language (NDL), which builds on Semantic Web techniques to create a distributed Topology Knowledge Base (TKB). The TKB can provide a collection of reachability graphs, showing connectivity rules among physical and/or virtual entities. Latching onto the Semantic Web provides network management with a new breed of tools—bots, compilers, browsers, both commercial offthe-shelf (COTS) and open source. The approach appears to be applicable to the Global Lambda Integrated Facility (GLIF) as well as other experimental communities. c ○ 2006 Jeroen van der Ham. Published by Elsevier B.V. All rights reserved