Publications

In this study, we present a thorough analysis of the job inter-arrival times, the waiting times at the queues, the execution times, and the data sizes exchanged at the kallisto.hellasgrid.gr cluster, which is part of the EGEE Grid infrastructure.

This paper presents an Erlang reduced load model to analyze Optical Burst Switched Grid networks. The model allows the evaluation of job blocking probabilities, in which blocking occurs in both the transport network and the resources where jobs are processed. Additionally, a novel routing strategy is introduced to improve the usage efficiency of the existing infrastructure.

Distributed applications or workflows need to access and use compute, storage and network resources simultaneously or chronologically coordinated respectively. Examples are distributed multi-physics simulations that use the combined computational performance and data storage of multiple clusters. A coordinated reservation and allocation of the resources is a prerequisite for the efficient use of such resources. This contribution describes the components of a system that provides Grid users with this functionality.

In this paper we presented an overview of the whole research that is currently being done under the FP6 EU funded Integrated Project Phosphorus that is addressing some of the key technical challenges to enable on-demand, end-to-end network services provisioning across multiple domains in a seamless and efficient way for e-science applications.

For demanding Grid applications that use resources at different cluster sites a reservation mechanism can ensure the availability of resources to guarantee a certain level of QoS. Besides computational and storage resources, we see the network as a reservable resource as well. Our approach to QoS is to schedule resources in the network for exclusive usage in advance. For this purpose, a flexible reservation mechanism is needed to meet the requirements of Grid applications and schedulers.

In this work authors propose a framework for Grid Networks that provides deterministic delay guarantees to its Guaranteed Service (GS) users and best effort service to its Best Effort (BE) imentally analyzed.

IFIP ONDM2008 travel grant award

In this study, we present a thorough analysis of the job arrival process in the EGEE infrastructure and of the time durations a job spends at different states in the EGEE environment. We define four delay components of the total job delay and model each component separately.

The presentation describes the potential usage of GMPLS and G²MPLS signalling protocols as a background for building a control plane for L1 and L2 network management.

This paper identifies and discusses the main issues and considerations that arise by network research and educational networks and network operators in order to facilitate the dissemination of G²MPLS control plane.

This paper proposes a novel anycast proxy architecture, which extends the anycast principle to a multi-domain scenario.

This paper studies the use of WDM in core optical networks with focus on resilience issues. More specifically the use and suitability of WDM to support differentiated survivability requirements of traffic generated by different applications are investigated.

This paper focuses on providing resilience in WDM optical networks supporting differentiated survivability traffic requirements. The work is based on the backup multiplexing technique in order to facilitate efficient resource sharing and investigates different routing and wavelength assignment schemes that considerably enhance the spare capacity utilization.

This article describes the GNS (Grid Network Services) requirements such as Grid resource discovery, service resiliency, Authorization Authentication Accounting (AAA) and advance reservation services, which are the main trigger factors of the G²MPLS control plane architectures (Overlay and Integrated), services procedures and the Grid-enabled network interfaces provided by IST Phosphorus project.

This paper addresses the problem of survivable lightpath provisioning in wavelength division multiplexed networks taking into consideration the optical signal performance degradation triggered by the physical impairments of transparent optical networks as a routing constraint. This work proposes a resource efficient provisioning scheme that takes into consideration both working and protecion traffic.

The usage of static timeslots is a well-known approach to handling advance reservations in the scope of Grid resource management. In this paper we enhance the timeslot-based approach by introducing dynamic timeslots and the notion of granularity. The main contribution is the development of an analytical model of the interrelation between user and system parameters in order to describe their impact on system efficiency and responsiveness.

This article introduces the concept of the Grid-GMPLS control plane architecture with particular focus on new services, deployment models, and interoperability issues of Grid-GMPLS and GMPLS control planes.