Athanassios Liakopoulos - Academia.edu (original) (raw)
Papers by Athanassios Liakopoulos
IEEE Communications Surveys and Tutorials, 1999
The TCP/IP protocol suite is the standard requirement for all applications that need to communica... more The TCP/IP protocol suite is the standard requirement for all applications that need to communicate over the Internet. As TCP/IP applications are unable to specify the QoS parameters needed for most Asynchronous Transfer Mode (ATM) services, they tend to use the unspecified bit rate (UBR) service category when running across ATM networks. The UBR service utilizes any bandwidth that is left unused by the rest of the ATM services. This has led the ATM Forum's Traffic Management Group to define a new service category called guaranteed frame rate (GFR). GFR is intended to provide minimum cell rate guarantees and fair access to excess bandwidth left over from higher-priority services. This article first presents a tutorial overview of GFR and then presents a survey of the research work that has been carried out toward the design and implementation of associated ATM switch mechanisms.
Reducing CO 2 emissions in order to address climate change is a difficult challenge but it may al... more Reducing CO 2 emissions in order to address climate change is a difficult challenge but it may also become an opportunity for improving citizens' behaviour towards the protection of the physical environment. Furthermore, as buildings are responsible for a significant portion of total energy consumption and emissions, improving their energy performance is clearly a key factor for accomplishing the EC climate and energy objectives. In this context, the Greek pilot in GEN6, a European Commission funded project, aims to influence the behaviour of the local school communities by raising their energy awareness. As discussed herein, the pilot will provide real-time energy efficiency services over IPv6enabled grids to the local educational community, providing students with information on their consumption patterns and raising awareness among them on the energy savings that behavioural changes may bring. Consequently, the pilot aims to reduce the participating school buildings' carbon footprint by at least 10% and prove that IPv6 may become an enabling technology for new advanced services. Currently, the installation of IPv6-enabled energy smart meters is in progress at 50+ schools for monitoring energy consumption but also for becoming an educational and social engagement tool for students. The GEN6 pilot, also aligned with the Greek School Network energy innovative programme, is further reinforced by hands-on workshops aiming at engaging students on issues of sustainability and empowering them to make further behavioural energy-saving changes. Results from the competition among the participating school communities are disseminated to the public through various means, such as a web portal, a blog, and social networks, which record the energy efficiency of participating schools and the effect of the actions taken.
Campus-wide information systems, Aug 1, 2006
Research backbone networks like GÉANT2 and the National Research and Education Networks are used ... more Research backbone networks like GÉANT2 and the National Research and Education Networks are used by a variety of scientists and research projects. These users and the network engineers operating the networks would like to get access to network performance metrics to optimise their use of the network and to troubleshoot performance degradations, when they happen. A variety of tools for performing network measurements already exist, and the perfSONAR architecture developed within the Joint Research Activity 1 (JRA1) of GÉANT2 aims at integrating them in a coherent framework. However, a harmonised definition of which metrics are mostly interesting and how measurements must be carried out is still lacking. In this paper we suggest the set of elementary metrics which are more relevant, along with indication about how to post process (or "transform", or "compose") them in order to obtain derived summary values that can quickly and intuitively give an indication of network performance. Methods to perform the composition are presented, together with constraints which have to be taken into account to get accurate results. In particular, delay measurements are the most delicate ones to compose. We carried out a series of experiments for proofing the validity of composition of delay metrics, and we briefly present some preliminary results.
Management of next generation networks is challenging due to increased complexity imposed by thei... more Management of next generation networks is challenging due to increased complexity imposed by their dynamic and heterogeneous characteristics. The deployment of mesh wireless networking topologies, the support of diverse networking functionalities and the existence of large number of heterogeneous devices make traditional approaches inappropriate. In such environments, the description of the basic networking entities and the interactions that are present, as well as the relationships among them, is crucial. Proper representation may facilitate the operation and management of the network, as well as the optimal adaptation to the current environmental conditions, and thus, optimise the performance of the network mechanisms. In this paper, a context model is proposed for ad-hoc networks aiming to present in detail the correlation among the network entities and interactions in dynamic environments. Specific functionalities that may be designed taking in account the description of the context model are described and indicative implementation scenarios are implemented and evaluated.
Springer eBooks, Oct 30, 2010
The concept of self-managing of autonomic networks is a paradigm shift from today’s management mo... more The concept of self-managing of autonomic networks is a paradigm shift from today’s management models, aiming at enabling networked nodes to self manage their behaviour within the constrains of the operator’s policies and objectives. The incorporation of the autonomicity concept to communications systems makes necessary the development of extensible context models. These enable the efficient representation of available information, needed for handling and distributing it. In this chapter, we focus on increasing context awareness towards the reduction of complexity in the management of multiple mechanisms realised in autonomic networks, giving special attention in managing, maintaining and exploiting autonomic entities in a unified way. An ontology is proposed that complies with the principles of a recently introduced Reference Model for autonomic network engineering/self-management within node and network architectures dubbed: the Generic Autonomic Network Architecture (GANA), which aims to identify autonomic behaviours realised via hierarchical control loops among self-managing elements.
smart objects through an overlay networking architecture
Network characteristics in the Internet of Things (large scale networks, more dynamic and more he... more Network characteristics in the Internet of Things (large scale networks, more dynamic and more heterogeneous) increase the complexity in the design and provision of advanced services, making the traditional approaches inefficient or even inappropriate. This paper focuses on the design of a novel and open overlay network architecture for the end-to-end interconnection of networked (physical or virtual) objects, the support of distributed information fusion and the provision of advanced services in challenging (e.g. large scale, heterogeneous, resource constrained, etc.) environments. The proposed architecture follows a layered-approach and aims at the provision of a generic framework that will facilitate the design and development of autonomic and decentralized services in Internet of Things deployments.
Creating a viable Evolution Path towards Self-Managing Future Internet via a Standardizable Refer... more Creating a viable Evolution Path towards Self-Managing Future Internet via a Standardizable Reference Model for Autonomic Network Engineering Ranganai Chaparadza1, Symeon Papavassiliou2, Timotheos Kastrinogiannis2, Martin Vigoureux 3, Emmanuel Dotaro3 ...
Deployment of IPv6 technology in research and commercial networks has accelerated in the last few... more Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffic gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit-speed Greek Research and Education Network (GRNET) and the IPv6-only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traf...
Remote Instrumentation Services on the e-Infrastructure, 2010
The concept of self-managing of autonomic networks is a paradigm shift from today’s management mo... more The concept of self-managing of autonomic networks is a paradigm shift from today’s management models, aiming at enabling networked nodes to self manage their behaviour within the constrains of the operator’s policies and objectives. The incorporation of the autonomicity concept to communications systems makes necessary the development of extensible context models. These enable the efficient representation of available information, needed for handling and distributing it. In this chapter, we focus on increasing context awareness towards the reduction of complexity in the management of multiple mechanisms realised in autonomic networks, giving special attention in managing, maintaining and exploiting autonomic entities in a unified way. An ontology is proposed that complies with the principles of a recently introduced Reference Model for autonomic network engineering/self-management within node and network architectures dubbed: the Generic Autonomic Network Architecture (GANA), which aims to identify autonomic behaviours realised via hierarchical control loops among self-managing elements.
Adoption of IPv6 technology has been accelerated in the last few years but there is limited exper... more Adoption of IPv6 technology has been accelerated in the last few years but there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks. As available software and hardware is designed to handle IPv4 packets, there is a need to accurately measure the performance of QoS mechanisms in an IPv6 environment. This paper discusses tests in the deployment of IPv6 QoS in core networks, namely the production dual stack GRNET and the IPv6-only 6NET networks, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common for IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state-of-the-art router cards at gigabit speeds.
International Journal of Network Management, 2009
Deployment of IPv6 technology in research and commercial networks has accelerated in the last few... more Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffi c gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffi c in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit-speed Greek Research and Education Network (GRNET) and the IPv6-only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffi c and provided different performance guarantees to portions of traffi c. The deployed QoS schema was common to IPv6 and IPv4; in most cases both v4 and v6 traffi c exhibited comparable performance per class, while imposing no signifi cantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are effi ciently supported with state-of-the-art router cards at gigabit speeds.
Adoption of IPv6 technology has been accelerated in the last few years but there is limited exper... more Adoption of IPv6 technology has been accelerated in the last few years but there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks. As available software and hardware is designed to handle IPv4 packets, there is a need to accurately measure the performance of QoS mechanisms in an IPv6 environment. This paper discusses tests in the deployment of IPv6 QoS in core networks, namely the production dual stack GRNET and the IPv6-only 6NET networks, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common for IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state-of-the-art router cards at gigabit speeds.
Adoption of IPv6 technology has been accelerated in the last few years but there is limited exper... more Adoption of IPv6 technology has been accelerated in the last few years but there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks. As available software and hardware is designed to handle IPv4 packets, there is a need to accurately measure the performance of QoS mechanisms in an IPv6 environment. This paper discusses tests in the deployment of IPv6 QoS in core networks, namely the production dual stack GRNET and the IPv6-only 6NET networks, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common for IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state-of-the-art router cards at gigabit speeds.
Deployment of IPv6 technology in research and commercial networks has accelerated in the last few... more Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffic gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit-speed Greek Research and Education Network (GRNET) and the IPv6-only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traf...
2005 14th IEEE Workshop on Local & Metropolitan Area Networks, 2005
... Géant is shown in 1 In this paper, Géant is considered as just another subscriber of the Athe... more ... Géant is shown in 1 In this paper, Géant is considered as just another subscriber of the Athens MAN. Fig. ... The resulting Premium IP service (equivalent to the Premium service discussed in this paper), was thus conceived, tested and finally introduced in Géant [14]. ...
2012 IEEE International Conference on Industrial Technology, 2012
ABSTRACT Smart grids are smart grids because they don't only transport electricity but al... more ABSTRACT Smart grids are smart grids because they don't only transport electricity but also information that will become an active part of the electricity supply system. Smart grid evolution has, thus, a lot to gain through the exploitation of emerging Future Internet networking technologies for the efficient collection and management of the acquired information. The capabilities for interconnection of numerous intelligent networking devices, the advanced monitoring and control of dynamic networking infrastructures and the efficient handling of large volumes of data are research areas that have direct applicability into the smart grid design and operation. This article presents our insights for the design of a novel and open overlay networking architecture for leveraging end-to-end interconnection of physical or virtual objects, for achieving decentralized data management, and for providing distributed services in smart grid environments. The proposed architecture follows a layered-approach and extends or adapts a set of existing overlay and IP protocols. In addition, a smart grid business-oriented scenario is briefly presented in order to explain how future technologies may be used to fulfill contemporary society needs.
2010 IEEE Globecom Workshops, 2010
The increasing size, complexity and the dynamic character of future networks make traditional mon... more The increasing size, complexity and the dynamic character of future networks make traditional monitoring systems inadequate to be continuously updated and sense the endless changes in the topology and communication conditions. The need for reduction in the network management complexity and the administrator's operational burden imposes the design and implementation of self-functionalities and the adoption of self-management schemes. We propose
2011 18th International Conference on Telecommunications, 2011
... Panagiotis Gouvas, Thanassis Bouras UBITECH Research Athens, Greece pgouvas@ubitech. eu, bour... more ... Panagiotis Gouvas, Thanassis Bouras UBITECH Research Athens, Greece pgouvas@ubitech. eu, bouras@ubitech.eu ... out any form of t any node can of medium-level g the Ubi-Chord ling cost, than cally identify its rticipation in the put(key, value)) We refer to set of ted with a ...
International Conference on Networking and Services (ICNS '07), 2007
Research networks, apart from pure IP packet-switched services, progressively introduce hybrid se... more Research networks, apart from pure IP packet-switched services, progressively introduce hybrid services, which combine packet switching and circuit switching technologies. Optical wavelengths (lambdas), SONET/SDH, 1/10 gigabit Ethernet are examples of technologies stitched together in order to realize point-to-point (P2P) services that cross multiple domains. Network monitoring aims to detect anomalies, assess performance degradations and localize faults in a network. In
IEEE Communications Surveys and Tutorials, 1999
The TCP/IP protocol suite is the standard requirement for all applications that need to communica... more The TCP/IP protocol suite is the standard requirement for all applications that need to communicate over the Internet. As TCP/IP applications are unable to specify the QoS parameters needed for most Asynchronous Transfer Mode (ATM) services, they tend to use the unspecified bit rate (UBR) service category when running across ATM networks. The UBR service utilizes any bandwidth that is left unused by the rest of the ATM services. This has led the ATM Forum's Traffic Management Group to define a new service category called guaranteed frame rate (GFR). GFR is intended to provide minimum cell rate guarantees and fair access to excess bandwidth left over from higher-priority services. This article first presents a tutorial overview of GFR and then presents a survey of the research work that has been carried out toward the design and implementation of associated ATM switch mechanisms.
Reducing CO 2 emissions in order to address climate change is a difficult challenge but it may al... more Reducing CO 2 emissions in order to address climate change is a difficult challenge but it may also become an opportunity for improving citizens' behaviour towards the protection of the physical environment. Furthermore, as buildings are responsible for a significant portion of total energy consumption and emissions, improving their energy performance is clearly a key factor for accomplishing the EC climate and energy objectives. In this context, the Greek pilot in GEN6, a European Commission funded project, aims to influence the behaviour of the local school communities by raising their energy awareness. As discussed herein, the pilot will provide real-time energy efficiency services over IPv6enabled grids to the local educational community, providing students with information on their consumption patterns and raising awareness among them on the energy savings that behavioural changes may bring. Consequently, the pilot aims to reduce the participating school buildings' carbon footprint by at least 10% and prove that IPv6 may become an enabling technology for new advanced services. Currently, the installation of IPv6-enabled energy smart meters is in progress at 50+ schools for monitoring energy consumption but also for becoming an educational and social engagement tool for students. The GEN6 pilot, also aligned with the Greek School Network energy innovative programme, is further reinforced by hands-on workshops aiming at engaging students on issues of sustainability and empowering them to make further behavioural energy-saving changes. Results from the competition among the participating school communities are disseminated to the public through various means, such as a web portal, a blog, and social networks, which record the energy efficiency of participating schools and the effect of the actions taken.
Campus-wide information systems, Aug 1, 2006
Research backbone networks like GÉANT2 and the National Research and Education Networks are used ... more Research backbone networks like GÉANT2 and the National Research and Education Networks are used by a variety of scientists and research projects. These users and the network engineers operating the networks would like to get access to network performance metrics to optimise their use of the network and to troubleshoot performance degradations, when they happen. A variety of tools for performing network measurements already exist, and the perfSONAR architecture developed within the Joint Research Activity 1 (JRA1) of GÉANT2 aims at integrating them in a coherent framework. However, a harmonised definition of which metrics are mostly interesting and how measurements must be carried out is still lacking. In this paper we suggest the set of elementary metrics which are more relevant, along with indication about how to post process (or "transform", or "compose") them in order to obtain derived summary values that can quickly and intuitively give an indication of network performance. Methods to perform the composition are presented, together with constraints which have to be taken into account to get accurate results. In particular, delay measurements are the most delicate ones to compose. We carried out a series of experiments for proofing the validity of composition of delay metrics, and we briefly present some preliminary results.
Management of next generation networks is challenging due to increased complexity imposed by thei... more Management of next generation networks is challenging due to increased complexity imposed by their dynamic and heterogeneous characteristics. The deployment of mesh wireless networking topologies, the support of diverse networking functionalities and the existence of large number of heterogeneous devices make traditional approaches inappropriate. In such environments, the description of the basic networking entities and the interactions that are present, as well as the relationships among them, is crucial. Proper representation may facilitate the operation and management of the network, as well as the optimal adaptation to the current environmental conditions, and thus, optimise the performance of the network mechanisms. In this paper, a context model is proposed for ad-hoc networks aiming to present in detail the correlation among the network entities and interactions in dynamic environments. Specific functionalities that may be designed taking in account the description of the context model are described and indicative implementation scenarios are implemented and evaluated.
Springer eBooks, Oct 30, 2010
The concept of self-managing of autonomic networks is a paradigm shift from today’s management mo... more The concept of self-managing of autonomic networks is a paradigm shift from today’s management models, aiming at enabling networked nodes to self manage their behaviour within the constrains of the operator’s policies and objectives. The incorporation of the autonomicity concept to communications systems makes necessary the development of extensible context models. These enable the efficient representation of available information, needed for handling and distributing it. In this chapter, we focus on increasing context awareness towards the reduction of complexity in the management of multiple mechanisms realised in autonomic networks, giving special attention in managing, maintaining and exploiting autonomic entities in a unified way. An ontology is proposed that complies with the principles of a recently introduced Reference Model for autonomic network engineering/self-management within node and network architectures dubbed: the Generic Autonomic Network Architecture (GANA), which aims to identify autonomic behaviours realised via hierarchical control loops among self-managing elements.
smart objects through an overlay networking architecture
Network characteristics in the Internet of Things (large scale networks, more dynamic and more he... more Network characteristics in the Internet of Things (large scale networks, more dynamic and more heterogeneous) increase the complexity in the design and provision of advanced services, making the traditional approaches inefficient or even inappropriate. This paper focuses on the design of a novel and open overlay network architecture for the end-to-end interconnection of networked (physical or virtual) objects, the support of distributed information fusion and the provision of advanced services in challenging (e.g. large scale, heterogeneous, resource constrained, etc.) environments. The proposed architecture follows a layered-approach and aims at the provision of a generic framework that will facilitate the design and development of autonomic and decentralized services in Internet of Things deployments.
Creating a viable Evolution Path towards Self-Managing Future Internet via a Standardizable Refer... more Creating a viable Evolution Path towards Self-Managing Future Internet via a Standardizable Reference Model for Autonomic Network Engineering Ranganai Chaparadza1, Symeon Papavassiliou2, Timotheos Kastrinogiannis2, Martin Vigoureux 3, Emmanuel Dotaro3 ...
Deployment of IPv6 technology in research and commercial networks has accelerated in the last few... more Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffic gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit-speed Greek Research and Education Network (GRNET) and the IPv6-only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traf...
Remote Instrumentation Services on the e-Infrastructure, 2010
The concept of self-managing of autonomic networks is a paradigm shift from today’s management mo... more The concept of self-managing of autonomic networks is a paradigm shift from today’s management models, aiming at enabling networked nodes to self manage their behaviour within the constrains of the operator’s policies and objectives. The incorporation of the autonomicity concept to communications systems makes necessary the development of extensible context models. These enable the efficient representation of available information, needed for handling and distributing it. In this chapter, we focus on increasing context awareness towards the reduction of complexity in the management of multiple mechanisms realised in autonomic networks, giving special attention in managing, maintaining and exploiting autonomic entities in a unified way. An ontology is proposed that complies with the principles of a recently introduced Reference Model for autonomic network engineering/self-management within node and network architectures dubbed: the Generic Autonomic Network Architecture (GANA), which aims to identify autonomic behaviours realised via hierarchical control loops among self-managing elements.
Adoption of IPv6 technology has been accelerated in the last few years but there is limited exper... more Adoption of IPv6 technology has been accelerated in the last few years but there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks. As available software and hardware is designed to handle IPv4 packets, there is a need to accurately measure the performance of QoS mechanisms in an IPv6 environment. This paper discusses tests in the deployment of IPv6 QoS in core networks, namely the production dual stack GRNET and the IPv6-only 6NET networks, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common for IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state-of-the-art router cards at gigabit speeds.
International Journal of Network Management, 2009
Deployment of IPv6 technology in research and commercial networks has accelerated in the last few... more Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffi c gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffi c in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit-speed Greek Research and Education Network (GRNET) and the IPv6-only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffi c and provided different performance guarantees to portions of traffi c. The deployed QoS schema was common to IPv6 and IPv4; in most cases both v4 and v6 traffi c exhibited comparable performance per class, while imposing no signifi cantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are effi ciently supported with state-of-the-art router cards at gigabit speeds.
Adoption of IPv6 technology has been accelerated in the last few years but there is limited exper... more Adoption of IPv6 technology has been accelerated in the last few years but there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks. As available software and hardware is designed to handle IPv4 packets, there is a need to accurately measure the performance of QoS mechanisms in an IPv6 environment. This paper discusses tests in the deployment of IPv6 QoS in core networks, namely the production dual stack GRNET and the IPv6-only 6NET networks, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common for IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state-of-the-art router cards at gigabit speeds.
Adoption of IPv6 technology has been accelerated in the last few years but there is limited exper... more Adoption of IPv6 technology has been accelerated in the last few years but there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks. As available software and hardware is designed to handle IPv4 packets, there is a need to accurately measure the performance of QoS mechanisms in an IPv6 environment. This paper discusses tests in the deployment of IPv6 QoS in core networks, namely the production dual stack GRNET and the IPv6-only 6NET networks, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traffic. The deployed QoS schema was common for IPv6 and IPv4; in most cases both v4 and v6 traffic exhibited comparable performance per class while imposing no significantly different overhead on network elements. A major conclusion of our tests is that the IPv6 QoS mechanisms are efficiently supported with state-of-the-art router cards at gigabit speeds.
Deployment of IPv6 technology in research and commercial networks has accelerated in the last few... more Deployment of IPv6 technology in research and commercial networks has accelerated in the last few years. Inevitably, as more advanced services take advantage of the new technology, IPv6 traffic gradually increases. Today, there is limited experience in the deployment of Quality of Service (QoS) for IPv6 traffic in backbone networks that support the Differentiated Services framework. As available software and hardware are designed to handle IPv4 packets, there is a need to accurately measure and validate performance of QoS mechanisms in an IPv6 environment. This paper discusses tests and technical challenges in the deployment of IPv6 QoS in core networks, namely the production dual stack gigabit-speed Greek Research and Education Network (GRNET) and the IPv6-only 6NET European test network, using both hardware and software platforms. In either case, we succeeded in delivering advanced transport services to IPv6 traffic and provided different performance guarantees to portions of traf...
2005 14th IEEE Workshop on Local & Metropolitan Area Networks, 2005
... Géant is shown in 1 In this paper, Géant is considered as just another subscriber of the Athe... more ... Géant is shown in 1 In this paper, Géant is considered as just another subscriber of the Athens MAN. Fig. ... The resulting Premium IP service (equivalent to the Premium service discussed in this paper), was thus conceived, tested and finally introduced in Géant [14]. ...
2012 IEEE International Conference on Industrial Technology, 2012
ABSTRACT Smart grids are smart grids because they don't only transport electricity but al... more ABSTRACT Smart grids are smart grids because they don't only transport electricity but also information that will become an active part of the electricity supply system. Smart grid evolution has, thus, a lot to gain through the exploitation of emerging Future Internet networking technologies for the efficient collection and management of the acquired information. The capabilities for interconnection of numerous intelligent networking devices, the advanced monitoring and control of dynamic networking infrastructures and the efficient handling of large volumes of data are research areas that have direct applicability into the smart grid design and operation. This article presents our insights for the design of a novel and open overlay networking architecture for leveraging end-to-end interconnection of physical or virtual objects, for achieving decentralized data management, and for providing distributed services in smart grid environments. The proposed architecture follows a layered-approach and extends or adapts a set of existing overlay and IP protocols. In addition, a smart grid business-oriented scenario is briefly presented in order to explain how future technologies may be used to fulfill contemporary society needs.
2010 IEEE Globecom Workshops, 2010
The increasing size, complexity and the dynamic character of future networks make traditional mon... more The increasing size, complexity and the dynamic character of future networks make traditional monitoring systems inadequate to be continuously updated and sense the endless changes in the topology and communication conditions. The need for reduction in the network management complexity and the administrator's operational burden imposes the design and implementation of self-functionalities and the adoption of self-management schemes. We propose
2011 18th International Conference on Telecommunications, 2011
... Panagiotis Gouvas, Thanassis Bouras UBITECH Research Athens, Greece pgouvas@ubitech. eu, bour... more ... Panagiotis Gouvas, Thanassis Bouras UBITECH Research Athens, Greece pgouvas@ubitech. eu, bouras@ubitech.eu ... out any form of t any node can of medium-level g the Ubi-Chord ling cost, than cally identify its rticipation in the put(key, value)) We refer to set of ted with a ...
International Conference on Networking and Services (ICNS '07), 2007
Research networks, apart from pure IP packet-switched services, progressively introduce hybrid se... more Research networks, apart from pure IP packet-switched services, progressively introduce hybrid services, which combine packet switching and circuit switching technologies. Optical wavelengths (lambdas), SONET/SDH, 1/10 gigabit Ethernet are examples of technologies stitched together in order to realize point-to-point (P2P) services that cross multiple domains. Network monitoring aims to detect anomalies, assess performance degradations and localize faults in a network. In