Dr. rer. nat. Michael Jarschel

• The Power of Composition: Abstracting a Multi-Device SDN Data Path Through a Single API. Geissler, Stefan; Herrnleben, Stefan; Bauer, Robert; Grigorjew, Alexej; Jarschel, Michael; Zinner, Thomas. In IEEE Transactions on Network and Service Management. 2019.
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  @article{info3-article-2019-11, author = {Geissler, Stefan and Herrnleben, Stefan and Bauer, Robert and Grigorjew, Alexej and Jarschel, Michael and Zinner, Thomas}, journal = {IEEE Transactions on Network and Service Management}, keywords = {sys:hidden:article}, month = 11, title = {The Power of Composition: Abstracting a Multi-Device SDN Data Path Through a Single API}, year = 2019 }

  %0 Journal Article %1 info3-article-2019-11 %A Geissler, Stefan %A Herrnleben, Stefan %A Bauer, Robert %A Grigorjew, Alexej %A Jarschel, Michael %A Zinner, Thomas %D 2019 %J IEEE Transactions on Network and Service Management %T The Power of Composition: Abstracting a Multi-Device SDN Data Path Through a Single API
• Survey of Performance Acceleration Techniques for Network Function Virtualization. Linguaglossa, Leonardo; Lange, Stanislav; Pontarelli, Salvatore; Retvari, Gabor; Rossi, Dario; Zinner, Thomas; Bificulo, Roberto; Jarschel, Michael; Bianchi, Giuseppe. In Proceedings of the IEEE. 2019.
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  The ongoing network softwarization trend holds the promise to revolutionize network infrastructures by making them more flexible, reconfigurable, portable, and more adaptive than ever. Still, the migration from hard-coded/hardwired network functions towards their software-programmable counterparts comes along with the need for tailored optimizations and acceleration techniques, so as to avoid, or at least mitigate, the throughput/latency performance degradation with respect to fixed function network elements. The contribution of this article is twofold. First, we provide a comprehensive overview of the host-based Network Function Virtualization (NFV) ecosystem, covering a broad range of techniques, from low level hardware acceleration and bump-in-the-wire offloading approaches, to high-level software acceleration solutions, including the virtualization technique itself. Second, we derive guidelines regarding the design, development, and operation of NFV-based deployments that meet the flexibility and scalability requirements of modern communication networks.

  @article{info3-article-2019-1, abstract = {The ongoing network softwarization trend holds the promise to revolutionize network infrastructures by making them more flexible, reconfigurable, portable, and more adaptive than ever. Still, the migration from hard-coded/hardwired network functions towards their software-programmable counterparts comes along with the need for tailored optimizations and acceleration techniques, so as to avoid, or at least mitigate, the throughput/latency performance degradation with respect to fixed function network elements. The contribution of this article is twofold. First, we provide a comprehensive overview of the host-based Network Function Virtualization (NFV) ecosystem, covering a broad range of techniques, from low level hardware acceleration and bump-in-the-wire offloading approaches, to high-level software acceleration solutions, including the virtualization technique itself. Second, we derive guidelines regarding the design, development, and operation of NFV-based deployments that meet the flexibility and scalability requirements of modern communication networks.}, author = {Linguaglossa, Leonardo and Lange, Stanislav and Pontarelli, Salvatore and Retvari, Gabor and Rossi, Dario and Zinner, Thomas and Bificulo, Roberto and Jarschel, Michael and Bianchi, Giuseppe}, journal = {Proceedings of the IEEE}, keywords = {sys:hidden:article}, month = {01}, title = {Survey of Performance Acceleration Techniques for Network Function Virtualization}, year = 2019 }

  %0 Journal Article %1 info3-article-2019-1 %A Linguaglossa, Leonardo %A Lange, Stanislav %A Pontarelli, Salvatore %A Retvari, Gabor %A Rossi, Dario %A Zinner, Thomas %A Bificulo, Roberto %A Jarschel, Michael %A Bianchi, Giuseppe %D 2019 %J Proceedings of the IEEE %T Survey of Performance Acceleration Techniques for Network Function Virtualization %X The ongoing network softwarization trend holds the promise to revolutionize network infrastructures by making them more flexible, reconfigurable, portable, and more adaptive than ever. Still, the migration from hard-coded/hardwired network functions towards their software-programmable counterparts comes along with the need for tailored optimizations and acceleration techniques, so as to avoid, or at least mitigate, the throughput/latency performance degradation with respect to fixed function network elements. The contribution of this article is twofold. First, we provide a comprehensive overview of the host-based Network Function Virtualization (NFV) ecosystem, covering a broad range of techniques, from low level hardware acceleration and bump-in-the-wire offloading approaches, to high-level software acceleration solutions, including the virtualization technique itself. Second, we derive guidelines regarding the design, development, and operation of NFV-based deployments that meet the flexibility and scalability requirements of modern communication networks.

• Context Monitoring for Improved System Performance and QoE. Metzger, Florian; Hoßfeld, Tobias; Skorin-Kapov, Lea; Liotou, Eirini; Pocta, Peter; Melvin, Hugh; Siris, Vasilios; Zgank, Andrej; Jarschel, Michael. In Autonomous Control for a Reliable Internet of Services: Methods, Models, Approaches, Techniques, Algorithms, and Tools, I. Ganchev, R. D. van der Mei, H. van den Berg (eds.). Springer International Publishing, 2018.
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  Whereas some application domains show a certain consensus on the role of system factors, human factors, and context factors, QoE management of multimedia systems and services is still faced with the challenge of identifying the key QoE influence factors. In this chapter, we focus on the potential of enhancing QoE management mechanisms by exploiting valuable context information. To get a good grip on the basics we first discuss a general framework for context monitoring and define context information, including technical, usage, social, economic, temporal, and physical factors. We then iterate the opportunities and challenges in involving context in QoE monitoring solutions, as context may be, e.g., hard to ascertain or very situational. The benefits of including context in QoE monitoring and management are demonstrated through use cases involving video flash crowds as well as online and cloud gaming. Finally, we discuss potential technical realizations of context-aware QoE monitoring and management derived based on the SDN paradigm.

  @incollection{info3-incollection-2018-3, abstract = {Whereas some application domains show a certain consensus on the role of system factors, human factors, and context factors, QoE management of multimedia systems and services is still faced with the challenge of identifying the key QoE influence factors. In this chapter, we focus on the potential of enhancing QoE management mechanisms by exploiting valuable context information. To get a good grip on the basics we first discuss a general framework for context monitoring and define context information, including technical, usage, social, economic, temporal, and physical factors. We then iterate the opportunities and challenges in involving context in QoE monitoring solutions, as context may be, e.g., hard to ascertain or very situational. The benefits of including context in QoE monitoring and management are demonstrated through use cases involving video flash crowds as well as online and cloud gaming. Finally, we discuss potential technical realizations of context-aware QoE monitoring and management derived based on the SDN paradigm.}, author = {Metzger, Florian and Hoßfeld, Tobias and Skorin-Kapov, Lea and Liotou, Eirini and Pocta, Peter and Melvin, Hugh and Siris, Vasilios and Zgank, Andrej and Jarschel, Michael}, booktitle = {Autonomous Control for a Reliable Internet of Services: Methods, Models, Approaches, Techniques, Algorithms, and Tools}, editor = {Ganchev, Ivan and van der Mei, R. D. and van den Berg, Hans}, keywords = {ua-net}, month = {05}, publisher = {Springer International Publishing}, title = {Context Monitoring for Improved System Performance and QoE}, year = 2018 }

  %0 Book Section %1 info3-incollection-2018-3 %A Metzger, Florian %A Hoßfeld, Tobias %A Skorin-Kapov, Lea %A Liotou, Eirini %A Pocta, Peter %A Melvin, Hugh %A Siris, Vasilios %A Zgank, Andrej %A Jarschel, Michael %B Autonomous Control for a Reliable Internet of Services: Methods, Models, Approaches, Techniques, Algorithms, and Tools %D 2018 %E Ganchev, Ivan %E van der Mei, R. D. %E van den Berg, Hans %I Springer International Publishing %T Context Monitoring for Improved System Performance and QoE %X Whereas some application domains show a certain consensus on the role of system factors, human factors, and context factors, QoE management of multimedia systems and services is still faced with the challenge of identifying the key QoE influence factors. In this chapter, we focus on the potential of enhancing QoE management mechanisms by exploiting valuable context information. To get a good grip on the basics we first discuss a general framework for context monitoring and define context information, including technical, usage, social, economic, temporal, and physical factors. We then iterate the opportunities and challenges in involving context in QoE monitoring solutions, as context may be, e.g., hard to ascertain or very situational. The benefits of including context in QoE monitoring and management are demonstrated through use cases involving video flash crowds as well as online and cloud gaming. Finally, we discuss potential technical realizations of context-aware QoE monitoring and management derived based on the SDN paradigm.
• Big-Data Helps SDN to Improve Application Specific Quality of Service. Schwarzmann, Susanna; Blenk, Andreas; Dobrijevic, Ognjen; Jarschel, Michael; Hotho, Andreas; Zinner, Thomas; Wamser, Florian. In Big Data and Software Defined Networks. Institution of Engineering and Technology (IET), 2018.
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  This chapter first provides an outline of the current results in the domains of: (a) quality-of-service (QoS) / quality-of-experience (QoE) control and management (CaM) for real-time multimedia services that is supported by software-defined networking (SDN), and (b) big data analytics and methods that are used for QoS/QoE CaM. Then, three specific use case scenarios with respect to video streaming services are presented, so as to illustrate the expected benefits of incorporating big data analytics into SDN-based CaM for the purposes of improving or optimizing QoS/QoE. In the end, we describe our vision and a high-level view of an SDN-based architecture for QoS/QoE CaM that is enriched with big data analytics' functional blocks and summarize corresponding challenges.

  @incollection{info3-incollection-2018-2, abstract = {This chapter first provides an outline of the current results in the domains of: (a) quality-of-service (QoS) / quality-of-experience (QoE) control and management (CaM) for real-time multimedia services that is supported by software-defined networking (SDN), and (b) big data analytics and methods that are used for QoS/QoE CaM. Then, three specific use case scenarios with respect to video streaming services are presented, so as to illustrate the expected benefits of incorporating big data analytics into SDN-based CaM for the purposes of improving or optimizing QoS/QoE. In the end, we describe our vision and a high-level view of an SDN-based architecture for QoS/QoE CaM that is enriched with big data analytics' functional blocks and summarize corresponding challenges.}, author = {Schwarzmann, Susanna and Blenk, Andreas and Dobrijevic, Ognjen and Jarschel, Michael and Hotho, Andreas and Zinner, Thomas and Wamser, Florian}, booktitle = {Big Data and Software Defined Networks}, keywords = {dfg-sdn}, month = {03}, publisher = {Institution of Engineering and Technology (IET)}, title = {Big-Data Helps SDN to Improve Application Specific Quality of Service}, year = 2018 }

  %0 Book Section %1 info3-incollection-2018-2 %A Schwarzmann, Susanna %A Blenk, Andreas %A Dobrijevic, Ognjen %A Jarschel, Michael %A Hotho, Andreas %A Zinner, Thomas %A Wamser, Florian %B Big Data and Software Defined Networks %D 2018 %I Institution of Engineering and Technology (IET) %T Big-Data Helps SDN to Improve Application Specific Quality of Service %X This chapter first provides an outline of the current results in the domains of: (a) quality-of-service (QoS) / quality-of-experience (QoE) control and management (CaM) for real-time multimedia services that is supported by software-defined networking (SDN), and (b) big data analytics and methods that are used for QoS/QoE CaM. Then, three specific use case scenarios with respect to video streaming services are presented, so as to illustrate the expected benefits of incorporating big data analytics into SDN-based CaM for the purposes of improving or optimizing QoS/QoE. In the end, we describe our vision and a high-level view of an SDN-based architecture for QoS/QoE CaM that is enriched with big data analytics' functional blocks and summarize corresponding challenges.

• A Multi-Objective Heuristic for the Optimization of Virtual Network Function Chain Placement. Lange, Stanislav; Grigorjew, Alexej; Zinner, Thomas; Tran-Gia, Phuoc; Jarschel, Michael. In 29th International Teletraffic Congress (ITC). 2017.
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  @inproceedings{info3-inproceedings-2017-16, author = {Lange, Stanislav and Grigorjew, Alexej and Zinner, Thomas and Tran-Gia, Phuoc and Jarschel, Michael}, booktitle = {29th International Teletraffic Congress (ITC)}, keywords = {sendate}, month = {09}, title = {A Multi-Objective Heuristic for the Optimization of Virtual Network Function Chain Placement}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-16 %A Lange, Stanislav %A Grigorjew, Alexej %A Zinner, Thomas %A Tran-Gia, Phuoc %A Jarschel, Michael %B 29th International Teletraffic Congress (ITC) %D 2017 %T A Multi-Objective Heuristic for the Optimization of Virtual Network Function Chain Placement
• TableVisor 2.0: Towards Full-Featured, Scalable and Hardware-Independent Multi Table Processing. Geissler, Stefan; Gebert, Steffen; Herrnleben, Stefan; Zinner, Thomas; Bauer, Robert; Jarschel, Michael. In NetSoft 2017, Best Student Paper Award. 2017.
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  Modern Software Defined Networking (SDN) appli- cations rely on sophisticated packet processing. However, there is a mismatch between control plane requirements and data plane capabilities caused by increasing hardware heterogeneity. To overcome this challenge, we propose TableVisor, a proxy-layer for the OpenFlow control channel that enables the flexible and scalable abstraction of multiple physical devices into one emu- lated data plane switch that meets the requirements of the control plane application. TableVisor registers with the SDN controller as a single switch with use-case specific capabilities. It translates the instructions and rules from the control application towards the appropriate physical device where they are executed. In this paper, we present the updated architecture and functionality of TableVisor as well as first evaluation results based on testbed experiments.

  @inproceedings{info3-inproceedings-2017-4, abstract = {Modern Software Defined Networking (SDN) appli- cations rely on sophisticated packet processing. However, there is a mismatch between control plane requirements and data plane capabilities caused by increasing hardware heterogeneity. To overcome this challenge, we propose TableVisor, a proxy-layer for the OpenFlow control channel that enables the flexible and scalable abstraction of multiple physical devices into one emu- lated data plane switch that meets the requirements of the control plane application. TableVisor registers with the SDN controller as a single switch with use-case specific capabilities. It translates the instructions and rules from the control application towards the appropriate physical device where they are executed. In this paper, we present the updated architecture and functionality of TableVisor as well as first evaluation results based on testbed experiments.}, author = {Geissler, Stefan and Gebert, Steffen and Herrnleben, Stefan and Zinner, Thomas and Bauer, Robert and Jarschel, Michael}, booktitle = {NetSoft 2017, Best Student Paper Award}, keywords = {sendate}, month = {02}, title = {TableVisor 2.0: Towards Full-Featured, Scalable and Hardware-Independent Multi Table Processing}, year = 2017 }

  %0 Conference Paper %1 info3-inproceedings-2017-4 %A Geissler, Stefan %A Gebert, Steffen %A Herrnleben, Stefan %A Zinner, Thomas %A Bauer, Robert %A Jarschel, Michael %B NetSoft 2017, Best Student Paper Award %D 2017 %T TableVisor 2.0: Towards Full-Featured, Scalable and Hardware-Independent Multi Table Processing %X Modern Software Defined Networking (SDN) appli- cations rely on sophisticated packet processing. However, there is a mismatch between control plane requirements and data plane capabilities caused by increasing hardware heterogeneity. To overcome this challenge, we propose TableVisor, a proxy-layer for the OpenFlow control channel that enables the flexible and scalable abstraction of multiple physical devices into one emu- lated data plane switch that meets the requirements of the control plane application. TableVisor registers with the SDN controller as a single switch with use-case specific capabilities. It translates the instructions and rules from the control application towards the appropriate physical device where they are executed. In this paper, we present the updated architecture and functionality of TableVisor as well as first evaluation results based on testbed experiments.
• SDN and NFV as Enabler for the Distributed Network Cloud. Hoffmann, Marco; Jarschel, Michael; Pries, Rastin; Schneider, Peter; Jukan, Admela; Bziuk, Wolfgang; Gebert, Steffen; Zinner, Thomas; Tran-Gia, Phuoc. In Mobile Networks and Applications. 2017.
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  @article{info3-article-2017-8, author = {Hoffmann, Marco and Jarschel, Michael and Pries, Rastin and Schneider, Peter and Jukan, Admela and Bziuk, Wolfgang and Gebert, Steffen and Zinner, Thomas and Tran-Gia, Phuoc}, journal = {Mobile Networks and Applications}, keywords = {sys:hidden:article}, title = {SDN and NFV as Enabler for the Distributed Network Cloud}, year = 2017 }

  %0 Journal Article %1 info3-article-2017-8 %A Hoffmann, Marco %A Jarschel, Michael %A Pries, Rastin %A Schneider, Peter %A Jukan, Admela %A Bziuk, Wolfgang %A Gebert, Steffen %A Zinner, Thomas %A Tran-Gia, Phuoc %D 2017 %J Mobile Networks and Applications %T SDN and NFV as Enabler for the Distributed Network Cloud

• Performance Evaluation Mechanisms for FlowMod Message Processing in OpenFlow Switches. Nguyen-Ngoc, Anh; Lange, Stanislav; Gebert, Steffen; Zinner, Thomas; Tran-Gia, Phuoc; Jarschel, Michael. In IEEE Sixth International Conference on Communications and Electronics. Ha Long City, Vietnam, 2016.
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  Network operators can benefit in terms of flexibility, cost, and vendor-independence when adopting the Software Defined Networking (SDN) paradigm. In many scenarios, the SDN controller orders the installation of new flow table entries in the switches it manages. Since such operations are handled in the slow path of the switches, the corresponding processing times constitute an important performance indicator for switches. This work focuses on a comparison of two mechanisms for evaluating the performance of OpenFlow switches with respect to the processing time of FlowMod messages. These mechanisms are characterized by different degrees of accuracy, cost, complexity, and the capability of performing measurements at run time. The first mechanism is based on the Spirent C1 dedicated testing platform, while the other uses a software module for the OpenDaylight controller. We assess their capabilities with respect to the abovementioned characteristics and quantify their accuracy by means of wiretaps that provide a ground truth regarding the measured processing times. By using three different switches in the experiments, it is possible to distinguish between hardware specific side-effects and general phenomena.

  @inproceedings{info3-inproceedings-2016-7, abstract = {Network operators can benefit in terms of flexibility, cost, and vendor-independence when adopting the Software Defined Networking (SDN) paradigm. In many scenarios, the SDN controller orders the installation of new flow table entries in the switches it manages. Since such operations are handled in the slow path of the switches, the corresponding processing times constitute an important performance indicator for switches. This work focuses on a comparison of two mechanisms for evaluating the performance of OpenFlow switches with respect to the processing time of FlowMod messages. These mechanisms are characterized by different degrees of accuracy, cost, complexity, and the capability of performing measurements at run time. The first mechanism is based on the Spirent C1 dedicated testing platform, while the other uses a software module for the OpenDaylight controller. We assess their capabilities with respect to the abovementioned characteristics and quantify their accuracy by means of wiretaps that provide a ground truth regarding the measured processing times. By using three different switches in the experiments, it is possible to distinguish between hardware specific side-effects and general phenomena.}, address = {Ha Long City, Vietnam}, author = {Nguyen-Ngoc, Anh and Lange, Stanislav and Gebert, Steffen and Zinner, Thomas and Tran-Gia, Phuoc and Jarschel, Michael}, booktitle = {IEEE Sixth International Conference on Communications and Electronics}, keywords = {sendate}, month = {07}, title = {Performance Evaluation Mechanisms for FlowMod Message Processing in OpenFlow Switches}, year = 2016 }

  %0 Conference Paper %1 info3-inproceedings-2016-7 %A Nguyen-Ngoc, Anh %A Lange, Stanislav %A Gebert, Steffen %A Zinner, Thomas %A Tran-Gia, Phuoc %A Jarschel, Michael %B IEEE Sixth International Conference on Communications and Electronics %C Ha Long City, Vietnam %D 2016 %T Performance Evaluation Mechanisms for FlowMod Message Processing in OpenFlow Switches %X Network operators can benefit in terms of flexibility, cost, and vendor-independence when adopting the Software Defined Networking (SDN) paradigm. In many scenarios, the SDN controller orders the installation of new flow table entries in the switches it manages. Since such operations are handled in the slow path of the switches, the corresponding processing times constitute an important performance indicator for switches. This work focuses on a comparison of two mechanisms for evaluating the performance of OpenFlow switches with respect to the processing time of FlowMod messages. These mechanisms are characterized by different degrees of accuracy, cost, complexity, and the capability of performing measurements at run time. The first mechanism is based on the Spirent C1 dedicated testing platform, while the other uses a software module for the OpenDaylight controller. We assess their capabilities with respect to the abovementioned characteristics and quantify their accuracy by means of wiretaps that provide a ground truth regarding the measured processing times. By using three different switches in the experiments, it is possible to distinguish between hardware specific side-effects and general phenomena.

• Heuristic Approaches to the Controller Placement Problem in Large Scale SDN Networks. Lange, Stanislav; Gebert, Steffen; Zinner, Thomas; Tran-Gia, Phuoc; Hock, David; Jarschel, Michael; Hoffmann, Marco. In IEEE Transactions on Network and Service Management - Special Issue on Efficient Management of SDN and NFV-based Systems, 12(1), pp. 4–17. 2015.
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  Software Defined Networking (SDN) marks a paradigm shift towards an externalized and logically centralized network control plane. A particularly important task in SDN architectures is that of controller placement, i.e., the positioning of a limited number of resources within a network in order to meet various requirements. These requirements range from latency constraints to failure tolerance and load balancing. In most scenarios, at least some of these objectives are competing, thus no single best placement is available and decision makers need to find a balanced trade-off. This work presents POCO, a framework for Pareto-based Optimal COntroller placement that provides operators with Pareto optimal placements with respect to different performance metrics. In its default configuration, POCO performs an exhaustive evaluation of all possible placements. While this is practically feasible for small and medium sized networks, realistic time and resource constraints call for an alternative in the context of large scale networks or dynamic networks whose properties change over time. For these scenarios, the POCO toolset is extended by a heuristic approach that is less accurate, but yields faster computation times. An evaluation of this heuristic is performed on a collection of real world network topologies from the Internet Topology Zoo. Utilizing a measure for quantifying the error introduced by the heuristic approach allows an analysis of the resulting trade-off between time and accuracy. Additionally, the proposed methods can be extended to solve similar virtual functions placement problems which appear in the context of Network Functions Virtualization (NFV).

  @article{info3-article-2015-131, abstract = {Software Defined Networking (SDN) marks a paradigm shift towards an externalized and logically centralized network control plane. A particularly important task in SDN architectures is that of controller placement, i.e., the positioning of a limited number of resources within a network in order to meet various requirements. These requirements range from latency constraints to failure tolerance and load balancing. In most scenarios, at least some of these objectives are competing, thus no single best placement is available and decision makers need to find a balanced trade-off. This work presents POCO, a framework for Pareto-based Optimal COntroller placement that provides operators with Pareto optimal placements with respect to different performance metrics. In its default configuration, POCO performs an exhaustive evaluation of all possible placements. While this is practically feasible for small and medium sized networks, realistic time and resource constraints call for an alternative in the context of large scale networks or dynamic networks whose properties change over time. For these scenarios, the POCO toolset is extended by a heuristic approach that is less accurate, but yields faster computation times. An evaluation of this heuristic is performed on a collection of real world network topologies from the Internet Topology Zoo. Utilizing a measure for quantifying the error introduced by the heuristic approach allows an analysis of the resulting trade-off between time and accuracy. Additionally, the proposed methods can be extended to solve similar virtual functions placement problems which appear in the context of Network Functions Virtualization (NFV).}, author = {Lange, Stanislav and Gebert, Steffen and Zinner, Thomas and Tran-Gia, Phuoc and Hock, David and Jarschel, Michael and Hoffmann, Marco}, journal = {IEEE Transactions on Network and Service Management - Special Issue on Efficient Management of SDN and NFV-based Systems}, keywords = {poco}, number = 1, pages = {4 - 17}, title = {Heuristic Approaches to the Controller Placement Problem in Large Scale SDN Networks}, volume = 12, year = 2015 }

  %0 Journal Article %1 info3-article-2015-131 %A Lange, Stanislav %A Gebert, Steffen %A Zinner, Thomas %A Tran-Gia, Phuoc %A Hock, David %A Jarschel, Michael %A Hoffmann, Marco %D 2015 %J IEEE Transactions on Network and Service Management - Special Issue on Efficient Management of SDN and NFV-based Systems %N 1 %P 4 - 17 %T Heuristic Approaches to the Controller Placement Problem in Large Scale SDN Networks %V 12 %X Software Defined Networking (SDN) marks a paradigm shift towards an externalized and logically centralized network control plane. A particularly important task in SDN architectures is that of controller placement, i.e., the positioning of a limited number of resources within a network in order to meet various requirements. These requirements range from latency constraints to failure tolerance and load balancing. In most scenarios, at least some of these objectives are competing, thus no single best placement is available and decision makers need to find a balanced trade-off. This work presents POCO, a framework for Pareto-based Optimal COntroller placement that provides operators with Pareto optimal placements with respect to different performance metrics. In its default configuration, POCO performs an exhaustive evaluation of all possible placements. While this is practically feasible for small and medium sized networks, realistic time and resource constraints call for an alternative in the context of large scale networks or dynamic networks whose properties change over time. For these scenarios, the POCO toolset is extended by a heuristic approach that is less accurate, but yields faster computation times. An evaluation of this heuristic is performed on a collection of real world network topologies from the Internet Topology Zoo. Utilizing a measure for quantifying the error introduced by the heuristic approach allows an analysis of the resulting trade-off between time and accuracy. Additionally, the proposed methods can be extended to solve similar virtual functions placement problems which appear in the context of Network Functions Virtualization (NFV).
• SDN-Enabled Energy-Efficient Network Management. Jarschel, Michael; Hoßfeld, Tobias; Davoli, Franco; Bolla, Raffaele; Bruschi, Roberto; Carrega, Alessandro. In Green Communications: Principles, Concepts and Practice, K. Samdanis, P. Rost, A. Maeder, M. Meo, C. Verikoukis (eds.). John Wiley & Sons, Ltd, 2015.
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  @incollection{info3-incollection-2015-1, author = {Jarschel, Michael and Hoßfeld, Tobias and Davoli, Franco and Bolla, Raffaele and Bruschi, Roberto and Carrega, Alessandro}, booktitle = {Green Communications: Principles, Concepts and Practice}, editor = {Samdanis, Konstantinos and Rost, Peter and Maeder, Andreas and Meo, Michela and Verikoukis, Christos}, keywords = {myown}, publisher = {John Wiley & Sons, Ltd}, title = {SDN-Enabled Energy-Efficient Network Management}, year = 2015 }

  %0 Book Section %1 info3-incollection-2015-1 %A Jarschel, Michael %A Hoßfeld, Tobias %A Davoli, Franco %A Bolla, Raffaele %A Bruschi, Roberto %A Carrega, Alessandro %B Green Communications: Principles, Concepts and Practice %D 2015 %E Samdanis, Konstantinos %E Rost, Peter %E Maeder, Andreas %E Meo, Michela %E Verikoukis, Christos %I John Wiley & Sons, Ltd %T SDN-Enabled Energy-Efficient Network Management
• Investigating Isolation between Virtual Networks in Case of Congestion for a Pronto 3290 Switch. Nguyen-Ngoc, Anh; Lange, Stanislav; Gebert, Steffen; Zinner, Thomas; Tran-Gia, Phuoc; Jarschel, Michael. In Workshop on Software-Defined Networking and Network Function Virtualization for Flexible Network Management (SDNFlex 2015). Cottbus, Germany, 2015.
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  Resource isolation between virtual networks is one of the key features of network virtualization. It is typically realized by configuring queues with specific rate guarantees on the egress ports of the network devices. The drawback of this architectural choice, however, is that traffic from several ingress ports may result in congestion on an egress port. Hence, the question arises to which extent isolation between virtual networks is realized in state-of-the-art hardware. This work aims at investigating whether congestion within one virtual network may affect the throughput performance of another virtual network. For that, measurements in a local testbed using a Pronto 3290 switch running an OpenFlow-enabling Pica8 firmware are performed.

  @inproceedings{info3-inproceedings-2015-508, abstract = {Resource isolation between virtual networks is one of the key features of network virtualization. It is typically realized by configuring queues with specific rate guarantees on the egress ports of the network devices. The drawback of this architectural choice, however, is that traffic from several ingress ports may result in congestion on an egress port. Hence, the question arises to which extent isolation between virtual networks is realized in state-of-the-art hardware. This work aims at investigating whether congestion within one virtual network may affect the throughput performance of another virtual network. For that, measurements in a local testbed using a Pronto 3290 switch running an OpenFlow-enabling Pica8 firmware are performed.}, address = {Cottbus, Germany}, author = {Nguyen-Ngoc, Anh and Lange, Stanislav and Gebert, Steffen and Zinner, Thomas and Tran-Gia, Phuoc and Jarschel, Michael}, booktitle = {Workshop on Software-Defined Networking and Network Function Virtualization for Flexible Network Management (SDNFlex 2015)}, keywords = {saser-siegfried}, month = {03}, title = {Investigating Isolation between Virtual Networks in Case of Congestion for a Pronto 3290 Switch}, year = 2015 }

  %0 Conference Paper %1 info3-inproceedings-2015-508 %A Nguyen-Ngoc, Anh %A Lange, Stanislav %A Gebert, Steffen %A Zinner, Thomas %A Tran-Gia, Phuoc %A Jarschel, Michael %B Workshop on Software-Defined Networking and Network Function Virtualization for Flexible Network Management (SDNFlex 2015) %C Cottbus, Germany %D 2015 %T Investigating Isolation between Virtual Networks in Case of Congestion for a Pronto 3290 Switch %X Resource isolation between virtual networks is one of the key features of network virtualization. It is typically realized by configuring queues with specific rate guarantees on the egress ports of the network devices. The drawback of this architectural choice, however, is that traffic from several ingress ports may result in congestion on an egress port. Hence, the question arises to which extent isolation between virtual networks is realized in state-of-the-art hardware. This work aims at investigating whether congestion within one virtual network may affect the throughput performance of another virtual network. For that, measurements in a local testbed using a Pronto 3290 switch running an OpenFlow-enabling Pica8 firmware are performed.
• Investigating the Impact of Network Topology on the Processing Times of SDN Controllers. Metter, Christopher; Gebert, Steffen; Lange, Stanislav; Zinner, Thomas; Tran-Gia, Phuoc; Jarschel, Michael. In Seventh IFIP/IEEE International Workshop on Management of the Future Internet. Ottawa, Canada, 2015.
  • [ Abstract ]
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  Software Defined Networking (SDN) introduces the concept of logically-centralized controllers in charge of managing the forwarding behavior of network elements. The new possibilities enabled through the centralization of control logic come with a certain risk: The controller might become a performance bottleneck. Therefore, ensuring sufficient controller performance is one of the crucial tasks prior to a successful SDN deployment. Furthermore, fine-grained traffic engineering, e.g., to achieve higher link utilization, results in a higher frequency of requests that are sent to the controller, which leads to an increased controller load. It is therefore important to analyze the capabilities of SDN controllers prior to deployment. This paper investigates two software implementations, the OpenDaylight and Ryu controllers. The control message throughput of different controllers has been studied several times already; however, it is not yet known what influence the number and topology of connected switches have. This paper investigates this influence in detail for a fat-tree data center topology and a WAN topology as well as 261 topologies with varying characteristics from the Internet Topology Zoo.

  @inproceedings{info3-inproceedings-2015-510, abstract = {Software Defined Networking (SDN) introduces the concept of logically-centralized controllers in charge of managing the forwarding behavior of network elements. The new possibilities enabled through the centralization of control logic come with a certain risk: The controller might become a performance bottleneck. Therefore, ensuring sufficient controller performance is one of the crucial tasks prior to a successful SDN deployment. Furthermore, fine-grained traffic engineering, e.g., to achieve higher link utilization, results in a higher frequency of requests that are sent to the controller, which leads to an increased controller load. It is therefore important to analyze the capabilities of SDN controllers prior to deployment. This paper investigates two software implementations, the OpenDaylight and Ryu controllers. The control message throughput of different controllers has been studied several times already; however, it is not yet known what influence the number and topology of connected switches have. This paper investigates this influence in detail for a fat-tree data center topology and a WAN topology as well as 261 topologies with varying characteristics from the Internet Topology Zoo.}, address = {Ottawa, Canada}, author = {Metter, Christopher and Gebert, Steffen and Lange, Stanislav and Zinner, Thomas and Tran-Gia, Phuoc and Jarschel, Michael}, booktitle = {Seventh IFIP/IEEE International Workshop on Management of the Future Internet}, keywords = {saser-siegfried}, month = {05}, title = {Investigating the Impact of Network Topology on the Processing Times of SDN Controllers}, year = 2015 }

  %0 Conference Paper %1 info3-inproceedings-2015-510 %A Metter, Christopher %A Gebert, Steffen %A Lange, Stanislav %A Zinner, Thomas %A Tran-Gia, Phuoc %A Jarschel, Michael %B Seventh IFIP/IEEE International Workshop on Management of the Future Internet %C Ottawa, Canada %D 2015 %T Investigating the Impact of Network Topology on the Processing Times of SDN Controllers %X Software Defined Networking (SDN) introduces the concept of logically-centralized controllers in charge of managing the forwarding behavior of network elements. The new possibilities enabled through the centralization of control logic come with a certain risk: The controller might become a performance bottleneck. Therefore, ensuring sufficient controller performance is one of the crucial tasks prior to a successful SDN deployment. Furthermore, fine-grained traffic engineering, e.g., to achieve higher link utilization, results in a higher frequency of requests that are sent to the controller, which leads to an increased controller load. It is therefore important to analyze the capabilities of SDN controllers prior to deployment. This paper investigates two software implementations, the OpenDaylight and Ryu controllers. The control message throughput of different controllers has been studied several times already; however, it is not yet known what influence the number and topology of connected switches have. This paper investigates this influence in detail for a fat-tree data center topology and a WAN topology as well as 261 topologies with varying characteristics from the Internet Topology Zoo.
• TableVisor: An Emulation Layer for Multi-Table OpenFlow Switches. Gebert, Steffen; Jarschel, Michael; Herrnleben, Stefan; Zinner, Thomas; Tran-Gia, Phuoc. In 4th European Workshop on Software Defined Networks (EWSDN). Bilbao, Spain, 2015.
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  This demonstration introduces TableVisor, which acts as a proxy layer between an OpenFlow controller and switches. Multiple hardware switches connect to TableVisor before it establishes a connection with the OpenFlow controller instance. During connection establishment, TableVisor advertises in the answer to the controller's features-request that this switch comprises a certain number of tables, which actually reflects the number of connected switches. All communication between controller and switch is passed through the proxy layer. Depending on the type of message, it will be answered directly by TableVisor (hello, features-reply), modified in such a way that particular fields are rewritten (packet-in, flow-mod), or a response merging data from multiple switches will be returned (flow-stats). The demonstration shows TableVisor in a MPLS use case using multiple switches, which is motivated by a mobile network scenario.

  @inproceedings{info3-inproceedings-2015-527, abstract = {This demonstration introduces TableVisor, which acts as a proxy layer between an OpenFlow controller and switches. Multiple hardware switches connect to TableVisor before it establishes a connection with the OpenFlow controller instance. During connection establishment, TableVisor advertises in the answer to the controller's features-request that this switch comprises a certain number of tables, which actually reflects the number of connected switches. All communication between controller and switch is passed through the proxy layer. Depending on the type of message, it will be answered directly by TableVisor (hello, features-reply), modified in such a way that particular fields are rewritten (packet-in, flow-mod), or a response merging data from multiple switches will be returned (flow-stats). The demonstration shows TableVisor in a MPLS use case using multiple switches, which is motivated by a mobile network scenario.}, address = {Bilbao, Spain}, author = {Gebert, Steffen and Jarschel, Michael and Herrnleben, Stefan and Zinner, Thomas and Tran-Gia, Phuoc}, booktitle = {4th European Workshop on Software Defined Networks (EWSDN)}, keywords = {sys:hidden:inproceedings}, month = {09}, title = {TableVisor: An Emulation Layer for Multi-Table OpenFlow Switches}, year = 2015 }

  %0 Conference Paper %1 info3-inproceedings-2015-527 %A Gebert, Steffen %A Jarschel, Michael %A Herrnleben, Stefan %A Zinner, Thomas %A Tran-Gia, Phuoc %B 4th European Workshop on Software Defined Networks (EWSDN) %C Bilbao, Spain %D 2015 %T TableVisor: An Emulation Layer for Multi-Table OpenFlow Switches %X This demonstration introduces TableVisor, which acts as a proxy layer between an OpenFlow controller and switches. Multiple hardware switches connect to TableVisor before it establishes a connection with the OpenFlow controller instance. During connection establishment, TableVisor advertises in the answer to the controller's features-request that this switch comprises a certain number of tables, which actually reflects the number of connected switches. All communication between controller and switch is passed through the proxy layer. Depending on the type of message, it will be answered directly by TableVisor (hello, features-reply), modified in such a way that particular fields are rewritten (packet-in, flow-mod), or a response merging data from multiple switches will be returned (flow-stats). The demonstration shows TableVisor in a MPLS use case using multiple switches, which is motivated by a mobile network scenario.
• Performance Benchmarking of a Software-Based LTE SGW. Lange, Stanislav; Nguyen-Ngoc, Anh; Gebert, Steffen; Zinner, Thomas; Jarschel, Michael; Koepsel, Andreas; Sune, Marc; Raumer, Daniel; Gallenmüller, Sebastian; Carle, Georg; Tran-Gia, Phuoc. In 2nd International Workshop on Management of SDN and NFV Systems. Barcelona, Spain, 2015.
  • [ Abstract ]
  • [ BibTeX ]
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  Network Functions Virtualization (NFV) is a concept that aims at providing network operators with benefits in terms of cost, flexibility, and vendor independence by utilizing virtualization techniques to run network functions as software on commercial off-the-shelf (COTS) hardware. In contrast, prior solutions rely on specialized hardware for each function. Performance evaluation of such systems usually requires a dedicated testbed for each individual component. Rather than analyzing these proprietary black-box components, Virtualized Network Functions (VNFs) are pieces of software that run on COTS hardware and whose properties can be investigated in a generic testbed. However, depending on the underlying hardware, operating system, and implementation, VNFs might behave differently. Therefore, mechanisms for the performance evaluation of VNFs should be similar to benchmarking of software, where different implementations are compared by applying them to predefined test cases and scenarios. This work presents a first step towards a benchmarking framework for VNFs. Given two different implementations of a VNF that acts as LTE Serving Gateway (SGW), influence factors and key performance indicators are identified and a comparison between the two mechanisms is drawn.

  @inproceedings{info3-inproceedings-2015-533, abstract = {Network Functions Virtualization (NFV) is a concept that aims at providing network operators with benefits in terms of cost, flexibility, and vendor independence by utilizing virtualization techniques to run network functions as software on commercial off-the-shelf (COTS) hardware. In contrast, prior solutions rely on specialized hardware for each function. Performance evaluation of such systems usually requires a dedicated testbed for each individual component. Rather than analyzing these proprietary black-box components, Virtualized Network Functions (VNFs) are pieces of software that run on COTS hardware and whose properties can be investigated in a generic testbed. However, depending on the underlying hardware, operating system, and implementation, VNFs might behave differently. Therefore, mechanisms for the performance evaluation of VNFs should be similar to benchmarking of software, where different implementations are compared by applying them to predefined test cases and scenarios. This work presents a first step towards a benchmarking framework for VNFs. Given two different implementations of a VNF that acts as LTE Serving Gateway (SGW), influence factors and key performance indicators are identified and a comparison between the two mechanisms is drawn.}, address = {Barcelona, Spain}, author = {Lange, Stanislav and Nguyen-Ngoc, Anh and Gebert, Steffen and Zinner, Thomas and Jarschel, Michael and Koepsel, Andreas and Sune, Marc and Raumer, Daniel and Gallenmüller, Sebastian and Carle, Georg and Tran-Gia, Phuoc}, booktitle = {2nd International Workshop on Management of SDN and NFV Systems}, keywords = {sys:hidden:inproceedings}, month = 11, title = {Performance Benchmarking of a Software-Based LTE SGW}, year = 2015 }

  %0 Conference Paper %1 info3-inproceedings-2015-533 %A Lange, Stanislav %A Nguyen-Ngoc, Anh %A Gebert, Steffen %A Zinner, Thomas %A Jarschel, Michael %A Koepsel, Andreas %A Sune, Marc %A Raumer, Daniel %A Gallenmüller, Sebastian %A Carle, Georg %A Tran-Gia, Phuoc %B 2nd International Workshop on Management of SDN and NFV Systems %C Barcelona, Spain %D 2015 %T Performance Benchmarking of a Software-Based LTE SGW %X Network Functions Virtualization (NFV) is a concept that aims at providing network operators with benefits in terms of cost, flexibility, and vendor independence by utilizing virtualization techniques to run network functions as software on commercial off-the-shelf (COTS) hardware. In contrast, prior solutions rely on specialized hardware for each function. Performance evaluation of such systems usually requires a dedicated testbed for each individual component. Rather than analyzing these proprietary black-box components, Virtualized Network Functions (VNFs) are pieces of software that run on COTS hardware and whose properties can be investigated in a generic testbed. However, depending on the underlying hardware, operating system, and implementation, VNFs might behave differently. Therefore, mechanisms for the performance evaluation of VNFs should be similar to benchmarking of software, where different implementations are compared by applying them to predefined test cases and scenarios. This work presents a first step towards a benchmarking framework for VNFs. Given two different implementations of a VNF that acts as LTE Serving Gateway (SGW), influence factors and key performance indicators are identified and a comparison between the two mechanisms is drawn.
• QoE for Cloud Gaming. Hoßfeld, Tobias; Metzger, Florian; Jarschel, Michael. In IEEE Communications Society E-Letter. 2015.
  • [ Abstract ]
  • [ BibTeX ]
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  Cloud Gaming combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users by processing the game in the cloud and streaming the contents to the player. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. However, at the same time the end device needs a broadband internet connection and the ability to display a video stream properly. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for Quality of Service (QoS) in terms of bandwidth and latency for the underlying network. In particular, there is a strong interest in the player’s Quality of Experience (QoE) by the involved stakeholders, ie, the game providers and the network operators. Given similar pricing schemes, players are likely to be influenced by expected and experienced quality. Thus, a provider is interested to understand QoE and to react on QoE problems by managing or adapting the service. There is also a strong academic interest, since QoE for cloud gaming as well as managing QoE for cloud gaming addresses a multitude of fascinating challenges in QoE. One might think that the topic of online video games is equally popular in research, but efforts are often solely focused on cloud gaming and its subjective QoE through user studies. Compared to plain video streaming, the inner properties of video games are not that straight-forward to observe from the outside. But to conduct proper measurements, it is essential to understand them.

  @article{info3-article-2015-9, abstract = {Cloud Gaming combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users by processing the game in the cloud and streaming the contents to the player. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. However, at the same time the end device needs a broadband internet connection and the ability to display a video stream properly. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for Quality of Service (QoS) in terms of bandwidth and latency for the underlying network. In particular, there is a strong interest in the player’s Quality of Experience (QoE) by the involved stakeholders, ie, the game providers and the network operators. Given similar pricing schemes, players are likely to be influenced by expected and experienced quality. Thus, a provider is interested to understand QoE and to react on QoE problems by managing or adapting the service. There is also a strong academic interest, since QoE for cloud gaming as well as managing QoE for cloud gaming addresses a multitude of fascinating challenges in QoE. One might think that the topic of online video games is equally popular in research, but efforts are often solely focused on cloud gaming and its subjective QoE through user studies. Compared to plain video streaming, the inner properties of video games are not that straight-forward to observe from the outside. But to conduct proper measurements, it is essential to understand them.}, author = {Hoßfeld, Tobias and Metzger, Florian and Jarschel, Michael}, journal = {IEEE Communications Society E-Letter}, keywords = {sys:hidden:article}, month = 11, title = {QoE for Cloud Gaming}, year = 2015 }

  %0 Journal Article %1 info3-article-2015-9 %A Hoßfeld, Tobias %A Metzger, Florian %A Jarschel, Michael %D 2015 %J IEEE Communications Society E-Letter %T QoE for Cloud Gaming %X Cloud Gaming combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users by processing the game in the cloud and streaming the contents to the player. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. However, at the same time the end device needs a broadband internet connection and the ability to display a video stream properly. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for Quality of Service (QoS) in terms of bandwidth and latency for the underlying network. In particular, there is a strong interest in the player’s Quality of Experience (QoE) by the involved stakeholders, ie, the game providers and the network operators. Given similar pricing schemes, players are likely to be influenced by expected and experienced quality. Thus, a provider is interested to understand QoE and to react on QoE problems by managing or adapting the service. There is also a strong academic interest, since QoE for cloud gaming as well as managing QoE for cloud gaming addresses a multitude of fascinating challenges in QoE. One might think that the topic of online video games is equally popular in research, but efforts are often solely focused on cloud gaming and its subjective QoE through user studies. Compared to plain video streaming, the inner properties of video games are not that straight-forward to observe from the outside. But to conduct proper measurements, it is essential to understand them.
• Demonstrating the Optimal Placement of Virtualized Cellular Network Functions in Case of Large Crowd Events. Gebert, Steffen; Jarschel, Michael; Hoffmann, Marco. Vienna, Austria, 2015, April.
  • [ BibTeX ]
  • [ EndNote ]
  @misc{info3-software-2015-22, address = {Vienna, Austria}, author = {Gebert, Steffen and Jarschel, Michael and Hoffmann, Marco}, booktitle = {Computer Communication Networks}, keywords = {sys:hidden:software}, month = {04}, title = {Demonstrating the Optimal Placement of Virtualized Cellular Network Functions in Case of Large Crowd Events}, year = 2015 }

  %0 Generic %1 info3-software-2015-22 %A Gebert, Steffen %A Jarschel, Michael %A Hoffmann, Marco %B Computer Communication Networks %C Vienna, Austria %D 2015 %T Demonstrating the Optimal Placement of Virtualized Cellular Network Functions in Case of Large Crowd Events

• OFCProbe: A Platform-Independent Tool for OpenFlow Controller Analysis. Jarschel, Michael; Metter, Christopher; Zinner, Thomas; Gebert, Steffen; Tran-Gia, Phuoc. In 5th IEEE International Conference on Communications and Electronics (IEEE ICCE 2014). Da Nang, Vietnam, 2014.
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  Controller performance and behavior are key to the operation of an SDN network. Therefore, choosing the right controller implementation and corresponding set of applications is essential. In order to facilitate this decision we previously introduced a tool for controller performance analysis called ”OFCBenchmark”. In this paper, we present ”OFCProbe” a platform-independent and extended re-design of our original approach. We describe the new architecture and explain the implemented features. Finally, we provide some sample results to illustrate the kind of investigations that can be performed using the tool.

  @inproceedings{info3-inproceedings-2014-496, abstract = {Controller performance and behavior are key to the operation of an SDN network. Therefore, choosing the right controller implementation and corresponding set of applications is essential. In order to facilitate this decision we previously introduced a tool for controller performance analysis called ”OFCBenchmark”. In this paper, we present ”OFCProbe” a platform-independent and extended re-design of our original approach. We describe the new architecture and explain the implemented features. Finally, we provide some sample results to illustrate the kind of investigations that can be performed using the tool.}, address = {Da Nang, Vietnam}, author = {Jarschel, Michael and Metter, Christopher and Zinner, Thomas and Gebert, Steffen and Tran-Gia, Phuoc}, booktitle = {5th IEEE International Conference on Communications and Electronics (IEEE ICCE 2014)}, keywords = {saser-siegfried}, month = {08}, title = {OFCProbe: A Platform-Independent Tool for OpenFlow Controller Analysis}, year = 2014 }

  %0 Conference Paper %1 info3-inproceedings-2014-496 %A Jarschel, Michael %A Metter, Christopher %A Zinner, Thomas %A Gebert, Steffen %A Tran-Gia, Phuoc %B 5th IEEE International Conference on Communications and Electronics (IEEE ICCE 2014) %C Da Nang, Vietnam %D 2014 %T OFCProbe: A Platform-Independent Tool for OpenFlow Controller Analysis %X Controller performance and behavior are key to the operation of an SDN network. Therefore, choosing the right controller implementation and corresponding set of applications is essential. In order to facilitate this decision we previously introduced a tool for controller performance analysis called ”OFCBenchmark”. In this paper, we present ”OFCProbe” a platform-independent and extended re-design of our original approach. We describe the new architecture and explain the implemented features. Finally, we provide some sample results to illustrate the kind of investigations that can be performed using the tool.
• Demonstrating the Optimal Placement of Virtualized Cellular Network Functions in Case of Large Crowd Events. Gebert, Steffen; Hock, David; Zinner, Thomas; Tran-Gia, Phuoc; Hoffmann, Marco; Jarschel, Michael; Schmidt, Ernst-Dieter; Braun, Ralf-Peter; Banse, Christian; Koepsel, Andreas. 2014, August.
  • [ BibTeX ]
  • [ EndNote ]
  @misc{info3-software-2014-21, author = {Gebert, Steffen and Hock, David and Zinner, Thomas and Tran-Gia, Phuoc and Hoffmann, Marco and Jarschel, Michael and Schmidt, Ernst-Dieter and Braun, Ralf-Peter and Banse, Christian and Koepsel, Andreas}, booktitle = {SIGCOMM}, keywords = {sys:hidden:software}, month = {08}, title = {Demonstrating the Optimal Placement of Virtualized Cellular Network Functions in Case of Large Crowd Events}, year = 2014 }

  %0 Generic %1 info3-software-2014-21 %A Gebert, Steffen %A Hock, David %A Zinner, Thomas %A Tran-Gia, Phuoc %A Hoffmann, Marco %A Jarschel, Michael %A Schmidt, Ernst-Dieter %A Braun, Ralf-Peter %A Banse, Christian %A Koepsel, Andreas %B SIGCOMM %D 2014 %T Demonstrating the Optimal Placement of Virtualized Cellular Network Functions in Case of Large Crowd Events
• Interfaces, Attributes, and Use Cases: A Compass for SDN. Jarschel, Michael; Zinner, Thomas; Hoßfeld, Tobias; Tran-Gia, Phuoc; Kellerer, Wolfgang. In IEEE Communications Magazine, 52, pp. 210–217. 2014.
  • [ Abstract ]
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  The term Software Defined Networking (SDN) is prevalent in today’s discussion about future communication networks. As with any new term or paradigm, however, no consistent definition regarding this technology has formed. The fragmented view on SDN results in legacy products being passed off by equipment vendors as SDN, academics mixing up the attributes of SDN with those of network virtualization, and users not fully understanding the benefits. Therefore, establishing SDN as a widely adopted technology beyond laboratories and insular deployments requires a compass to navigate the multitude of ideas and concepts that make up SDN today. The contribution of this article represents an important step toward such an instrument. It gives a thorough definition of SDN and its interfaces as well as a list of its key attributes. Furthermore, a mapping of interfaces and attributes to SDN use cases is provided, highlighting the relevance of the interfaces and attributes for each scenario. This compass gives guidance to a potential adopter of SDN on whether SDN is in fact the right technology for a specific use case.

  @article{info3-article-2014-124, abstract = {The term Software Defined Networking (SDN) is prevalent in today’s discussion about future communication networks. As with any new term or paradigm, however, no consistent definition regarding this technology has formed. The fragmented view on SDN results in legacy products being passed off by equipment vendors as SDN, academics mixing up the attributes of SDN with those of network virtualization, and users not fully understanding the benefits. Therefore, establishing SDN as a widely adopted technology beyond laboratories and insular deployments requires a compass to navigate the multitude of ideas and concepts that make up SDN today. The contribution of this article represents an important step toward such an instrument. It gives a thorough definition of SDN and its interfaces as well as a list of its key attributes. Furthermore, a mapping of interfaces and attributes to SDN use cases is provided, highlighting the relevance of the interfaces and attributes for each scenario. This compass gives guidance to a potential adopter of SDN on whether SDN is in fact the right technology for a specific use case.}, author = {Jarschel, Michael and Zinner, Thomas and Hoßfeld, Tobias and Tran-Gia, Phuoc and Kellerer, Wolfgang}, journal = {IEEE Communications Magazine}, keywords = {sys:hidden:article}, month = {06}, pages = {210-217}, title = {Interfaces, Attributes, and Use Cases: A Compass for SDN}, volume = 52, year = 2014 }

  %0 Journal Article %1 info3-article-2014-124 %A Jarschel, Michael %A Zinner, Thomas %A Hoßfeld, Tobias %A Tran-Gia, Phuoc %A Kellerer, Wolfgang %D 2014 %J IEEE Communications Magazine %P 210-217 %T Interfaces, Attributes, and Use Cases: A Compass for SDN %V 52 %X The term Software Defined Networking (SDN) is prevalent in today’s discussion about future communication networks. As with any new term or paradigm, however, no consistent definition regarding this technology has formed. The fragmented view on SDN results in legacy products being passed off by equipment vendors as SDN, academics mixing up the attributes of SDN with those of network virtualization, and users not fully understanding the benefits. Therefore, establishing SDN as a widely adopted technology beyond laboratories and insular deployments requires a compass to navigate the multitude of ideas and concepts that make up SDN today. The contribution of this article represents an important step toward such an instrument. It gives a thorough definition of SDN and its interfaces as well as a list of its key attributes. Furthermore, a mapping of interfaces and attributes to SDN use cases is provided, highlighting the relevance of the interfaces and attributes for each scenario. This compass gives guidance to a potential adopter of SDN on whether SDN is in fact the right technology for a specific use case.
• Dynamic Application-Aware Resource Management Using Software-Defined Networking: Implementation Prospects and Challenges. Zinner, Thomas; Jarschel, Michael; Blenk, Andreas; Wamser, Florian; Kellerer, Wolfgang. In IFIP/IEEE International Workshop on Quality of Experience Centric Management (QCMan). Krakow, Poland, 2014.
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  Today’s Internet does not provide an exchange of information between applications and networks, which may result in poor application performance. Concepts such as applicationaware networking or network-aware application programming try to overcome these limitations. The introduction of Software- Defined Networking (SDN) opens a path towards the realization of an enhanced interaction between networks and applications. Hence, a more dynamic and demand-based allocation of network resources to heterogeneous applications can be realized. The implementation of the resource management action, however, may have an impact on the data transport and application quality. This paper summarizes resource management mechanisms provided by current SDN approaches based on OpenFlow and exemplary evaluates implementation prospects and challenges.

  @inproceedings{info3-inproceedings-2014-490, abstract = {Today’s Internet does not provide an exchange of information between applications and networks, which may result in poor application performance. Concepts such as applicationaware networking or network-aware application programming try to overcome these limitations. The introduction of Software- Defined Networking (SDN) opens a path towards the realization of an enhanced interaction between networks and applications. Hence, a more dynamic and demand-based allocation of network resources to heterogeneous applications can be realized. The implementation of the resource management action, however, may have an impact on the data transport and application quality. This paper summarizes resource management mechanisms provided by current SDN approaches based on OpenFlow and exemplary evaluates implementation prospects and challenges.}, address = {Krakow, Poland}, author = {Zinner, Thomas and Jarschel, Michael and Blenk, Andreas and Wamser, Florian and Kellerer, Wolfgang}, booktitle = {IFIP/IEEE International Workshop on Quality of Experience Centric Management (QCMan)}, keywords = {sys:hidden:inproceedings}, month = {05}, title = {Dynamic Application-Aware Resource Management Using Software-Defined Networking: Implementation Prospects and Challenges}, year = 2014 }

  %0 Conference Paper %1 info3-inproceedings-2014-490 %A Zinner, Thomas %A Jarschel, Michael %A Blenk, Andreas %A Wamser, Florian %A Kellerer, Wolfgang %B IFIP/IEEE International Workshop on Quality of Experience Centric Management (QCMan) %C Krakow, Poland %D 2014 %T Dynamic Application-Aware Resource Management Using Software-Defined Networking: Implementation Prospects and Challenges %X Today’s Internet does not provide an exchange of information between applications and networks, which may result in poor application performance. Concepts such as applicationaware networking or network-aware application programming try to overcome these limitations. The introduction of Software- Defined Networking (SDN) opens a path towards the realization of an enhanced interaction between networks and applications. Hence, a more dynamic and demand-based allocation of network resources to heterogeneous applications can be realized. The implementation of the resource management action, however, may have an impact on the data transport and application quality. This paper summarizes resource management mechanisms provided by current SDN approaches based on OpenFlow and exemplary evaluates implementation prospects and challenges.
• An Assessment of Applications and Performance Analysis of Software Defined Networking. Jarschel, Michael. 2014, May.
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  @phdthesis{info3-dissertation-2014-36, author = {Jarschel, Michael}, keywords = {sys:hidden:dissertation}, month = {05}, title = {An Assessment of Applications and Performance Analysis of Software Defined Networking}, year = 2014 }

  %0 Thesis %1 info3-dissertation-2014-36 %A Jarschel, Michael %D 2014 %T An Assessment of Applications and Performance Analysis of Software Defined Networking

• A Compass Through SDN Networks. Technical Report (488), . Zinner, Thomas; Jarschel, Michael; Hoßfeld, Tobias; Tran-Gia, Phuoc; Kellerer, Wolfgang. University of Wuerzburg, 2013.
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  @techreport{info3-techreport-2013-262, author = {Zinner, Thomas and Jarschel, Michael and Hoßfeld, Tobias and Tran-Gia, Phuoc and Kellerer, Wolfgang}, institution = {University of Wuerzburg}, keywords = {sys:hidden:techreport}, month = 10, number = 488, title = {A Compass Through SDN Networks}, year = 2013 }

  %0 Report %1 info3-techreport-2013-262 %A Zinner, Thomas %A Jarschel, Michael %A Hoßfeld, Tobias %A Tran-Gia, Phuoc %A Kellerer, Wolfgang %D 2013 %N 488 %T A Compass Through SDN Networks
• Operational Benefits and Performance Pitfalls of SDN for the Example of OpenFlow. Jarschel, Michael. ITG FG521 Workshop: Zukünftige Netzarchitekturen, Stuttgart, Germany, 2013, February 22.
  • [ BibTeX ]
  • [ EndNote ]
  @presentation{info3-talk-2013-461, address = {ITG FG521 Workshop: Zukünftige Netzarchitekturen, Stuttgart, Germany}, author = {Jarschel, Michael}, keywords = {sys:hidden:presentation}, month = {02}, title = {Operational Benefits and Performance Pitfalls of SDN for the Example of OpenFlow}, year = 2013 }

  %0 Generic %1 info3-talk-2013-461 %A Jarschel, Michael %C ITG FG521 Workshop: Zukünftige Netzarchitekturen, Stuttgart, Germany %D 2013 %T Operational Benefits and Performance Pitfalls of SDN for the Example of OpenFlow
• An OpenFlow Extension for the OMNeT++ INET Framework. Klein, Dominik; Jarschel, Michael. In 6th International Workshop on OMNeT++. Cannes, France, 2013.
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  Software Defined Networking (SDN) is a new paradigm for communication networks which separates the control plane from the data plane of forwarding elements. This way, SDN constitutes a flexible architecture that allows quick and easy configuration of network devices. This ability is particularly useful when networks have to be adapted to changing traffic volumes of different applications running on the network. OpenFlow is currently the most prominent approach which implements the SDN concept and offers a high flexibility in the routing of network flows. In this paper, we describe the implementation of our model of the OpenFlow system in the INET framework for OMNeT++. We present performance results to show the correctness of our model. As a first application, we use the simulation model to assess the round-trip-times in a theoretical OpenFlow deployment in a real topology of a North-American Testbed.

  @inproceedings{info3-inproceedings-2013-461, abstract = {Software Defined Networking (SDN) is a new paradigm for communication networks which separates the control plane from the data plane of forwarding elements. This way, SDN constitutes a flexible architecture that allows quick and easy configuration of network devices. This ability is particularly useful when networks have to be adapted to changing traffic volumes of different applications running on the network. OpenFlow is currently the most prominent approach which implements the SDN concept and offers a high flexibility in the routing of network flows. In this paper, we describe the implementation of our model of the OpenFlow system in the INET framework for OMNeT++. We present performance results to show the correctness of our model. As a first application, we use the simulation model to assess the round-trip-times in a theoretical OpenFlow deployment in a real topology of a North-American Testbed.}, address = {Cannes, France}, author = {Klein, Dominik and Jarschel, Michael}, booktitle = {6th International Workshop on OMNeT++}, keywords = {openflow}, month = {03}, title = {An OpenFlow Extension for the OMNeT++ INET Framework}, year = 2013 }

  %0 Conference Paper %1 info3-inproceedings-2013-461 %A Klein, Dominik %A Jarschel, Michael %B 6th International Workshop on OMNeT++ %C Cannes, France %D 2013 %T An OpenFlow Extension for the OMNeT++ INET Framework %X Software Defined Networking (SDN) is a new paradigm for communication networks which separates the control plane from the data plane of forwarding elements. This way, SDN constitutes a flexible architecture that allows quick and easy configuration of network devices. This ability is particularly useful when networks have to be adapted to changing traffic volumes of different applications running on the network. OpenFlow is currently the most prominent approach which implements the SDN concept and offers a high flexibility in the routing of network flows. In this paper, we describe the implementation of our model of the OpenFlow system in the INET framework for OMNeT++. We present performance results to show the correctness of our model. As a first application, we use the simulation model to assess the round-trip-times in a theoretical OpenFlow deployment in a real topology of a North-American Testbed.
• Pareto-Optimal Resilient Controller Placement in SDN-based Core Networks. Hock, David; Hartmann, Matthias; Gebert, Steffen; Jarschel, Michael; Zinner, Thomas; Tran-Gia, Phuoc. In 25th International Teletraffic Congress (ITC). Shanghai, China, 2013.
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  With the introduction of Software Defined Networking (SDN), the concept of an external and optionally centralized network control plane, i.e. controller, is drawing the attention of researchers and industry. A particularly important task in the SDN context is the placement of such external resources in the network. In this paper, we discuss important aspects of the controller placement problem with a focus on SDN-based core networks, including different types of resilience and failure tolerance. When several performance and resilience metrics are considered, there is usually no single best controller placement solution, but a trade-off between these metrics. We introduce our framework for resilient Pareto-based Optimal COntroller-placement (POCO) that provides the operator of a network with all Pareto-optimal placements. The ideas and mechanisms are illustrated using the Internet2 OS3E topology and further evaluated on more than 140 topologies of the Topology Zoo. In particular, our findings reveal that for most of the topologies more than 20% of all nodes need to be controllers to assure a continuous connection of all nodes to one of the controllers in any arbitrary double link or node failure scenario.

  @inproceedings{info3-inproceedings-2013-466, abstract = {With the introduction of Software Defined Networking (SDN), the concept of an external and optionally centralized network control plane, i.e. controller, is drawing the attention of researchers and industry. A particularly important task in the SDN context is the placement of such external resources in the network. In this paper, we discuss important aspects of the controller placement problem with a focus on SDN-based core networks, including different types of resilience and failure tolerance. When several performance and resilience metrics are considered, there is usually no single best controller placement solution, but a trade-off between these metrics. We introduce our framework for resilient Pareto-based Optimal COntroller-placement (POCO) that provides the operator of a network with all Pareto-optimal placements. The ideas and mechanisms are illustrated using the Internet2 OS3E topology and further evaluated on more than 140 topologies of the Topology Zoo. In particular, our findings reveal that for most of the topologies more than 20% of all nodes need to be controllers to assure a continuous connection of all nodes to one of the controllers in any arbitrary double link or node failure scenario.}, address = {Shanghai, China}, author = {Hock, David and Hartmann, Matthias and Gebert, Steffen and Jarschel, Michael and Zinner, Thomas and Tran-Gia, Phuoc}, booktitle = {25th International Teletraffic Congress (ITC)}, keywords = {poco}, month = {09}, title = {Pareto-Optimal Resilient Controller Placement in SDN-based Core Networks}, year = 2013 }

  %0 Conference Paper %1 info3-inproceedings-2013-466 %A Hock, David %A Hartmann, Matthias %A Gebert, Steffen %A Jarschel, Michael %A Zinner, Thomas %A Tran-Gia, Phuoc %B 25th International Teletraffic Congress (ITC) %C Shanghai, China %D 2013 %T Pareto-Optimal Resilient Controller Placement in SDN-based Core Networks %X With the introduction of Software Defined Networking (SDN), the concept of an external and optionally centralized network control plane, i.e. controller, is drawing the attention of researchers and industry. A particularly important task in the SDN context is the placement of such external resources in the network. In this paper, we discuss important aspects of the controller placement problem with a focus on SDN-based core networks, including different types of resilience and failure tolerance. When several performance and resilience metrics are considered, there is usually no single best controller placement solution, but a trade-off between these metrics. We introduce our framework for resilient Pareto-based Optimal COntroller-placement (POCO) that provides the operator of a network with all Pareto-optimal placements. The ideas and mechanisms are illustrated using the Internet2 OS3E topology and further evaluated on more than 140 topologies of the Topology Zoo. In particular, our findings reveal that for most of the topologies more than 20% of all nodes need to be controllers to assure a continuous connection of all nodes to one of the controllers in any arbitrary double link or node failure scenario.
• SDN-based Application-Aware Networking on the Example of YouTube Video Streaming. Jarschel, Michael; Wamser, Florian; Höhn, Thomas; Zinner, Thomas; Tran-Gia, Phuoc. In 2nd European Workshop on Software Defined Networks (EWSDN 2013). Berlin, Germany, 2013.
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  Application-Aware Networking is a promising approach to provide good application quality to users in scenarios with limited network resources, like today’s access networks. With SDN, a particularly interesting method to enable flowbased traffic management in networks has become available. In this work we take a look at how a specific application, i.e., YouTube Streaming, can benefit from such an SDN-based Application-Aware Network. We implement and investigate an approach based on Deep Packet Inspection (DPI) and one based on direct information input from the application in an OpenFlow testbed in order to show, how these different types of application information can be exploited to enhance the Quality of Experience (QoE). Furthermore, we determine the overhead caused by each of the presented approaches.

  @inproceedings{info3-inproceedings-2013-477, abstract = {Application-Aware Networking is a promising approach to provide good application quality to users in scenarios with limited network resources, like today’s access networks. With SDN, a particularly interesting method to enable flowbased traffic management in networks has become available. In this work we take a look at how a specific application, i.e., YouTube Streaming, can benefit from such an SDN-based Application-Aware Network. We implement and investigate an approach based on Deep Packet Inspection (DPI) and one based on direct information input from the application in an OpenFlow testbed in order to show, how these different types of application information can be exploited to enhance the Quality of Experience (QoE). Furthermore, we determine the overhead caused by each of the presented approaches.}, address = {Berlin, Germany}, author = {Jarschel, Michael and Wamser, Florian and Höhn, Thomas and Zinner, Thomas and Tran-Gia, Phuoc}, booktitle = {2nd European Workshop on Software Defined Networks (EWSDN 2013)}, keywords = {demobenefit}, month = 10, title = {SDN-based Application-Aware Networking on the Example of YouTube Video Streaming}, year = 2013 }

  %0 Conference Paper %1 info3-inproceedings-2013-477 %A Jarschel, Michael %A Wamser, Florian %A Höhn, Thomas %A Zinner, Thomas %A Tran-Gia, Phuoc %B 2nd European Workshop on Software Defined Networks (EWSDN 2013) %C Berlin, Germany %D 2013 %T SDN-based Application-Aware Networking on the Example of YouTube Video Streaming %X Application-Aware Networking is a promising approach to provide good application quality to users in scenarios with limited network resources, like today’s access networks. With SDN, a particularly interesting method to enable flowbased traffic management in networks has become available. In this work we take a look at how a specific application, i.e., YouTube Streaming, can benefit from such an SDN-based Application-Aware Network. We implement and investigate an approach based on Deep Packet Inspection (DPI) and one based on direct information input from the application in an OpenFlow testbed in order to show, how these different types of application information can be exploited to enhance the Quality of Experience (QoE). Furthermore, we determine the overhead caused by each of the presented approaches.
• On the Accuracy of Leveraging SDN for Passive Network Measurements. Jarschel, Michael; Zinner, Thomas; Höhn, Thomas; Tran-Gia, Phuoc. In Australasian Telecommunication Networks & Applications Conference (ATNAC 2013). Christchurch, New Zealand, 2013.
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  Network Measurement has emerged as one promising field of application for Software Defined Networking. The reason for this is that the logically centralized control plane of an SDN network inherently has to aggregate network state information in order to function. This circumstance can be leveraged for network measurements at the SDN controller without the need for additional equipment or active – and possibly disruptive – measurements in the network itself. However, the accuracy and potential resource overhead of this approach has not been discussed. In this paper we compare an SDN-based solution to actual traffic measurements in order to determine its accuracy and resource demand by performing tests in an OpenFlow testbed.

  @inproceedings{info3-inproceedings-2013-480, abstract = {Network Measurement has emerged as one promising field of application for Software Defined Networking. The reason for this is that the logically centralized control plane of an SDN network inherently has to aggregate network state information in order to function. This circumstance can be leveraged for network measurements at the SDN controller without the need for additional equipment or active – and possibly disruptive – measurements in the network itself. However, the accuracy and potential resource overhead of this approach has not been discussed. In this paper we compare an SDN-based solution to actual traffic measurements in order to determine its accuracy and resource demand by performing tests in an OpenFlow testbed.}, address = {Christchurch, New Zealand}, author = {Jarschel, Michael and Zinner, Thomas and Höhn, Thomas and Tran-Gia, Phuoc}, booktitle = {Australasian Telecommunication Networks & Applications Conference (ATNAC 2013)}, keywords = {sys:hidden:inproceedings}, month = 11, title = {On the Accuracy of Leveraging SDN for Passive Network Measurements}, year = 2013 }

  %0 Conference Paper %1 info3-inproceedings-2013-480 %A Jarschel, Michael %A Zinner, Thomas %A Höhn, Thomas %A Tran-Gia, Phuoc %B Australasian Telecommunication Networks & Applications Conference (ATNAC 2013) %C Christchurch, New Zealand %D 2013 %T On the Accuracy of Leveraging SDN for Passive Network Measurements %X Network Measurement has emerged as one promising field of application for Software Defined Networking. The reason for this is that the logically centralized control plane of an SDN network inherently has to aggregate network state information in order to function. This circumstance can be leveraged for network measurements at the SDN controller without the need for additional equipment or active – and possibly disruptive – measurements in the network itself. However, the accuracy and potential resource overhead of this approach has not been discussed. In this paper we compare an SDN-based solution to actual traffic measurements in order to determine its accuracy and resource demand by performing tests in an OpenFlow testbed.
• Network Function Virtualization: Towards the Commoditization of Middle Boxes. Jarschel, Michael. DATEV Trendscout, Nürnberg, Germany, 2013, November 5.
  • [ BibTeX ]
  • [ EndNote ]
  @presentation{info3-talk-2013-474, address = {DATEV Trendscout, Nürnberg, Germany}, author = {Jarschel, Michael}, keywords = {sys:hidden:presentation}, month = 11, title = {Network Function Virtualization: Towards the Commoditization of Middle Boxes}, year = 2013 }

  %0 Generic %1 info3-talk-2013-474 %A Jarschel, Michael %C DATEV Trendscout, Nürnberg, Germany %D 2013 %T Network Function Virtualization: Towards the Commoditization of Middle Boxes
• On the Accuracy of Leveraging SDN for Passive Network Measurements. Jarschel, Michael; Zinner, Thomas; Höhn, Thomas; Tran-Gia, Phuoc. Australasian Telecommunication Networks & Applications Conference (ATNAC 2013), Christchurch, New Zealand, 2013, November 20.
  • [ BibTeX ]
  • [ EndNote ]
  @presentation{info3-talk-2013-475, address = {Australasian Telecommunication Networks & Applications Conference (ATNAC 2013), Christchurch, New Zealand}, author = {Jarschel, Michael and Zinner, Thomas and Höhn, Thomas and Tran-Gia, Phuoc}, keywords = {sys:hidden:presentation}, month = 11, title = {On the Accuracy of Leveraging SDN for Passive Network Measurements}, year = 2013 }

  %0 Generic %1 info3-talk-2013-475 %A Jarschel, Michael %A Zinner, Thomas %A Höhn, Thomas %A Tran-Gia, Phuoc %C Australasian Telecommunication Networks & Applications Conference (ATNAC 2013), Christchurch, New Zealand %D 2013 %T On the Accuracy of Leveraging SDN for Passive Network Measurements
• SDN-based Application-Aware Networking on the Example of YouTube Video Streaming. Jarschel, Michael; Wamser, Florian; Höhn, Thomas; Zinner, Thomas; Tran-Gia, Phuoc. 2nd European Workshop on Software Defined Networks (EWSDN 2013), Berlin, Germany, 2013, October 11.
  • [ BibTeX ]
  • [ EndNote ]
  @presentation{info3-talk-2013-473, address = {2nd European Workshop on Software Defined Networks (EWSDN 2013), Berlin, Germany}, author = {Jarschel, Michael and Wamser, Florian and Höhn, Thomas and Zinner, Thomas and Tran-Gia, Phuoc}, keywords = {demobenefit}, month = 10, title = {SDN-based Application-Aware Networking on the Example of YouTube Video Streaming}, year = 2013 }

  %0 Generic %1 info3-talk-2013-473 %A Jarschel, Michael %A Wamser, Florian %A Höhn, Thomas %A Zinner, Thomas %A Tran-Gia, Phuoc %C 2nd European Workshop on Software Defined Networks (EWSDN 2013), Berlin, Germany %D 2013 %T SDN-based Application-Aware Networking on the Example of YouTube Video Streaming

• SDN - The Future of Networking?. Jarschel, Michael. DATEV Trendscout, Nürnberg, Germany, 2012, May 24.
  • [ BibTeX ]
  • [ EndNote ]
  @presentation{info3-talk-2012-440, address = {DATEV Trendscout, Nürnberg, Germany}, author = {Jarschel, Michael}, keywords = {sys:hidden:presentation}, month = {05}, title = {SDN - The Future of Networking?}, year = 2012 }

  %0 Generic %1 info3-talk-2012-440 %A Jarschel, Michael %C DATEV Trendscout, Nürnberg, Germany %D 2012 %T SDN - The Future of Networking?
• Gaming in the clouds: QoE and the users’ perspective. Jarschel, Michael; Schlosser, Daniel; Scheuring, Sven; Hoßfeld, Tobias. In Mathematical and Computer Modelling. 2012.
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  Cloud Gaming is a new kind of service, which combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users remotely from a data center. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. The end device only needs a broadband internet connection and the ability to display High Definition (HD) video. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for service quality in terms of bandwidth and latency for the underlying network. In this paper we present the results of a subjective user study we conducted into the user-perceived quality of experience (QoE) in Cloud Gaming. We design a measurement environment, that emulates this new type of service, define tests for users to assess the QoE, derive Key Influence Factors (KFI) and influences of content and perception from our results.

  @article{info3-article-2012-95, abstract = {Cloud Gaming is a new kind of service, which combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users remotely from a data center. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. The end device only needs a broadband internet connection and the ability to display High Definition (HD) video. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for service quality in terms of bandwidth and latency for the underlying network. In this paper we present the results of a subjective user study we conducted into the user-perceived quality of experience (QoE) in Cloud Gaming. We design a measurement environment, that emulates this new type of service, define tests for users to assess the QoE, derive Key Influence Factors (KFI) and influences of content and perception from our results.}, author = {Jarschel, Michael and Schlosser, Daniel and Scheuring, Sven and Hoßfeld, Tobias}, journal = {Mathematical and Computer Modelling}, keywords = {sys:hidden:article}, title = {Gaming in the clouds: QoE and the users’ perspective}, year = 2012 }

  %0 Journal Article %1 info3-article-2012-95 %A Jarschel, Michael %A Schlosser, Daniel %A Scheuring, Sven %A Hoßfeld, Tobias %D 2012 %J Mathematical and Computer Modelling %T Gaming in the clouds: QoE and the users’ perspective %X Cloud Gaming is a new kind of service, which combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users remotely from a data center. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. The end device only needs a broadband internet connection and the ability to display High Definition (HD) video. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for service quality in terms of bandwidth and latency for the underlying network. In this paper we present the results of a subjective user study we conducted into the user-perceived quality of experience (QoE) in Cloud Gaming. We design a measurement environment, that emulates this new type of service, define tests for users to assess the QoE, derive Key Influence Factors (KFI) and influences of content and perception from our results.
• SDN - A Technical Perspective. Jarschel, Michael; Tran-Gia, Phuoc. DATEV Technical Trendscout, Nürnberg, Germany, 2012, May 24.
  • [ BibTeX ]
  • [ EndNote ]
  @presentation{info3-talk-2012-439, address = {DATEV Technical Trendscout, Nürnberg, Germany}, author = {Jarschel, Michael and Tran-Gia, Phuoc}, keywords = {sys:hidden:presentation}, month = {05}, title = {SDN - A Technical Perspective}, year = 2012 }

  %0 Generic %1 info3-talk-2012-439 %A Jarschel, Michael %A Tran-Gia, Phuoc %C DATEV Technical Trendscout, Nürnberg, Germany %D 2012 %T SDN - A Technical Perspective
• On the Usability of OpenFlow in Data Center Environments. Pries, Rastin; Jarschel, Michael; Goll, Sebastian. In Workshop on Clouds, Networks and Data Centers collocated with the IEEE International Conference on Communications (ICC 2012). Ottawa, Canada, 2012.
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  Since its introduction OpenFlow has been used as an enabler for network experiments in a variety of fields. Although OpenFlow was initially only used in the research domain, the concept is now finding its way into data centers due to the relatively cheap hardware and high flexibility. In this paper, we take a look at the scalability and usability of OpenFlow in data centers. Based on data center traffic models and OpenFlow measurements, we evaluate whether OpenFlow is able to cope with the short flow inter-arrival times in data centers by means of simulation.

  @inproceedings{info3-inproceedings-2012-438, abstract = {Since its introduction OpenFlow has been used as an enabler for network experiments in a variety of fields. Although OpenFlow was initially only used in the research domain, the concept is now finding its way into data centers due to the relatively cheap hardware and high flexibility. In this paper, we take a look at the scalability and usability of OpenFlow in data centers. Based on data center traffic models and OpenFlow measurements, we evaluate whether OpenFlow is able to cope with the short flow inter-arrival times in data centers by means of simulation.}, address = {Ottawa, Canada}, author = {Pries, Rastin and Jarschel, Michael and Goll, Sebastian}, booktitle = {Workshop on Clouds, Networks and Data Centers collocated with the IEEE International Conference on Communications (ICC 2012)}, keywords = {openflow}, month = {06}, title = {On the Usability of OpenFlow in Data Center Environments}, year = 2012 }

  %0 Conference Paper %1 info3-inproceedings-2012-438 %A Pries, Rastin %A Jarschel, Michael %A Goll, Sebastian %B Workshop on Clouds, Networks and Data Centers collocated with the IEEE International Conference on Communications (ICC 2012) %C Ottawa, Canada %D 2012 %T On the Usability of OpenFlow in Data Center Environments %X Since its introduction OpenFlow has been used as an enabler for network experiments in a variety of fields. Although OpenFlow was initially only used in the research domain, the concept is now finding its way into data centers due to the relatively cheap hardware and high flexibility. In this paper, we take a look at the scalability and usability of OpenFlow in data centers. Based on data center traffic models and OpenFlow measurements, we evaluate whether OpenFlow is able to cope with the short flow inter-arrival times in data centers by means of simulation.
• An OpenFlow-Based Energy-Efficient Data Center Approach. Jarschel, Michael; Pries, Rastin. Helsinki, Finland, 2012, August.
  • [ BibTeX ]
  • [ EndNote ]
  @misc{info3-software-2012-10, address = {Helsinki, Finland}, author = {Jarschel, Michael and Pries, Rastin}, booktitle = {SIGCOMM}, keywords = {sys:hidden:software}, month = {08}, title = {An OpenFlow-Based Energy-Efficient Data Center Approach}, year = 2012 }

  %0 Generic %1 info3-software-2012-10 %A Jarschel, Michael %A Pries, Rastin %B SIGCOMM %C Helsinki, Finland %D 2012 %T An OpenFlow-Based Energy-Efficient Data Center Approach
• A Flexible OpenFlow-Controller Benchmark. Jarschel, Michael; Lehrieder, Frank; Magyari, Zsolt; Pries, Rastin. In 1st European Workshop on Software Defined Networks (EWSDN 2012). Darmstadt, Germany, 2012.
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  Software defined networking (SDN) promises a way to more flexible networks that can adapt to changing demands. At the same time these networks should also benefit from simpler management mechanisms. This is achieved by moving the network control out of the forwarding devices to purpose-tailored software-applications on top of a ”networking operating system”. Currently, the most notable representative of this approach is OpenFlow. In the OpenFlow architecture the operating system is represented by the OpenFlow controller. As the key component of the OpenFlow ecosystem, the behavior and performance of the controller are significant for the entire network. Therefore, it is important to understand these influence factors, when planning an OpenFlow-based SDN deployment. In this work, we introduce a tool to help achieving just that - a flexible OpenFlow controller benchmark. The benchmark creates a set of message-generating virtual switches, which can be configured independently from each other to emulate a certain scenario and also keep their own statistics. This way a granular controller performance analysis is possible.

  @inproceedings{info3-inproceedings-2012-455, abstract = {Software defined networking (SDN) promises a way to more flexible networks that can adapt to changing demands. At the same time these networks should also benefit from simpler management mechanisms. This is achieved by moving the network control out of the forwarding devices to purpose-tailored software-applications on top of a ”networking operating system”. Currently, the most notable representative of this approach is OpenFlow. In the OpenFlow architecture the operating system is represented by the OpenFlow controller. As the key component of the OpenFlow ecosystem, the behavior and performance of the controller are significant for the entire network. Therefore, it is important to understand these influence factors, when planning an OpenFlow-based SDN deployment. In this work, we introduce a tool to help achieving just that - a flexible OpenFlow controller benchmark. The benchmark creates a set of message-generating virtual switches, which can be configured independently from each other to emulate a certain scenario and also keep their own statistics. This way a granular controller performance analysis is possible.}, address = {Darmstadt, Germany}, author = {Jarschel, Michael and Lehrieder, Frank and Magyari, Zsolt and Pries, Rastin}, booktitle = {1st European Workshop on Software Defined Networks (EWSDN 2012)}, keywords = {openflow}, month = 10, title = {A Flexible OpenFlow-Controller Benchmark}, year = 2012 }

  %0 Conference Paper %1 info3-inproceedings-2012-455 %A Jarschel, Michael %A Lehrieder, Frank %A Magyari, Zsolt %A Pries, Rastin %B 1st European Workshop on Software Defined Networks (EWSDN 2012) %C Darmstadt, Germany %D 2012 %T A Flexible OpenFlow-Controller Benchmark %X Software defined networking (SDN) promises a way to more flexible networks that can adapt to changing demands. At the same time these networks should also benefit from simpler management mechanisms. This is achieved by moving the network control out of the forwarding devices to purpose-tailored software-applications on top of a ”networking operating system”. Currently, the most notable representative of this approach is OpenFlow. In the OpenFlow architecture the operating system is represented by the OpenFlow controller. As the key component of the OpenFlow ecosystem, the behavior and performance of the controller are significant for the entire network. Therefore, it is important to understand these influence factors, when planning an OpenFlow-based SDN deployment. In this work, we introduce a tool to help achieving just that - a flexible OpenFlow controller benchmark. The benchmark creates a set of message-generating virtual switches, which can be configured independently from each other to emulate a certain scenario and also keep their own statistics. This way a granular controller performance analysis is possible.
• A Flexible OpenFlow-Controller Benchmark. Jarschel, Michael; Lehrieder, Frank; Magyari, Zsolt; Pries, Rastin. European Workshop on Software Defined Networks, Darmstadt, Germany, 2012, October 26.
  • [ BibTeX ]
  • [ EndNote ]
  @presentation{info3-talk-2012-450, address = {European Workshop on Software Defined Networks, Darmstadt, Germany}, author = {Jarschel, Michael and Lehrieder, Frank and Magyari, Zsolt and Pries, Rastin}, keywords = {openflow}, month = 10, title = {A Flexible OpenFlow-Controller Benchmark}, year = 2012 }

  %0 Generic %1 info3-talk-2012-450 %A Jarschel, Michael %A Lehrieder, Frank %A Magyari, Zsolt %A Pries, Rastin %C European Workshop on Software Defined Networks, Darmstadt, Germany %D 2012 %T A Flexible OpenFlow-Controller Benchmark

• IPOM: Interactive Proxy Management Tool for Future Communication Networks Using OpenFlow. Jarschel, Michael; Schlosser, Daniel; Duelli, Michael; Pries, Rastin. Kaiserslautern, Germany, 2011, June.
  • [ BibTeX ]
  • [ EndNote ]
  @misc{info3-software-2011-6, address = {Kaiserslautern, Germany}, author = {Jarschel, Michael and Schlosser, Daniel and Duelli, Michael and Pries, Rastin}, booktitle = {Next Generation Internet (NGI)}, keywords = {sys:hidden:software}, month = {06}, title = {IPOM: Interactive Proxy Management Tool for Future Communication Networks Using OpenFlow}, year = 2011 }

  %0 Generic %1 info3-software-2011-6 %A Jarschel, Michael %A Schlosser, Daniel %A Duelli, Michael %A Pries, Rastin %B Next Generation Internet (NGI) %C Kaiserslautern, Germany %D 2011 %T IPOM: Interactive Proxy Management Tool for Future Communication Networks Using OpenFlow
• Provisioning and Operation of Virtual Networks. Meier, Sebastian; Barisch, Marc; Kirstädter, Andreas; Schlosser, Daniel; Duelli, Michael; Jarschel, Michael; Hoßfeld, Tobias; Hoffmann, Klaus; Hoffmann, Marco; Kellerer, Wolfgang; Khan, Ashiq; Jurca, Dan; Kozu, Kazuyuki. In Electronic Communications of the EASST, Kommunikation in Verteilten Systemen 2011, 37. 2011.
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  In today’s Internet, requirements of services regarding the underlying transport network are very diverse. In the future, this diversity will increase and make it harder to accommodate all services in a single network. A possible approach to keep up with this diversity in future networks is the deployment of isolated, custom tailored networks on top of a single shared physical substrate. The COMCON (COntrol and Monitoring of COexisting Networks) project aims to define a reference architecture for setup, control, and monitoring of virtual networks on a provider- and operator-grade level. In this paper, we present the building blocks and interfaces of our architecture.

  @article{info3-article-2011-87, abstract = {In today’s Internet, requirements of services regarding the underlying transport network are very diverse. In the future, this diversity will increase and make it harder to accommodate all services in a single network. A possible approach to keep up with this diversity in future networks is the deployment of isolated, custom tailored networks on top of a single shared physical substrate. The COMCON (COntrol and Monitoring of COexisting Networks) project aims to define a reference architecture for setup, control, and monitoring of virtual networks on a provider- and operator-grade level. In this paper, we present the building blocks and interfaces of our architecture.}, author = {Meier, Sebastian and Barisch, Marc and Kirstädter, Andreas and Schlosser, Daniel and Duelli, Michael and Jarschel, Michael and Hoßfeld, Tobias and Hoffmann, Klaus and Hoffmann, Marco and Kellerer, Wolfgang and Khan, Ashiq and Jurca, Dan and Kozu, Kazuyuki}, journal = {Electronic Communications of the EASST, Kommunikation in Verteilten Systemen 2011}, keywords = {sys:hidden:article}, month = {03}, title = {Provisioning and Operation of Virtual Networks}, volume = 37, year = 2011 }

  %0 Journal Article %1 info3-article-2011-87 %A Meier, Sebastian %A Barisch, Marc %A Kirstädter, Andreas %A Schlosser, Daniel %A Duelli, Michael %A Jarschel, Michael %A Hoßfeld, Tobias %A Hoffmann, Klaus %A Hoffmann, Marco %A Kellerer, Wolfgang %A Khan, Ashiq %A Jurca, Dan %A Kozu, Kazuyuki %D 2011 %J Electronic Communications of the EASST, Kommunikation in Verteilten Systemen 2011 %T Provisioning and Operation of Virtual Networks %V 37 %X In today’s Internet, requirements of services regarding the underlying transport network are very diverse. In the future, this diversity will increase and make it harder to accommodate all services in a single network. A possible approach to keep up with this diversity in future networks is the deployment of isolated, custom tailored networks on top of a single shared physical substrate. The COMCON (COntrol and Monitoring of COexisting Networks) project aims to define a reference architecture for setup, control, and monitoring of virtual networks on a provider- and operator-grade level. In this paper, we present the building blocks and interfaces of our architecture.
• COntrol and Management of COexisting Networks (COMCON). Schlosser, Daniel; Jarschel, Michael; Meier, Sebastian; Hoffmann, Marco; Hoffmann, Klaus; Hoßfeld, Tobias; Khan, Ashiq; Kellerer, Wolfgang; Kirstädter, Andreas; Köhler, Stefan; Morper, Hans-Jochen; Schmid, Matthias. San Juan, Puerto Rico, 2011, March.
  • [ BibTeX ]
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  @misc{info3-poster-2011-26, address = {San Juan, Puerto Rico}, author = {Schlosser, Daniel and Jarschel, Michael and Meier, Sebastian and Hoffmann, Marco and Hoffmann, Klaus and Hoßfeld, Tobias and Khan, Ashiq and Kellerer, Wolfgang and Kirstädter, Andreas and Köhler, Stefan and Morper, Hans-Jochen and Schmid, Matthias}, booktitle = {1st DFG / NSF Young Researchers Workshop at GEC10}, keywords = {sys:hidden:poster}, month = {03}, title = {COntrol and Management of COexisting Networks (COMCON)}, year = 2011 }

  %0 Generic %1 info3-poster-2011-26 %A Schlosser, Daniel %A Jarschel, Michael %A Meier, Sebastian %A Hoffmann, Marco %A Hoffmann, Klaus %A Hoßfeld, Tobias %A Khan, Ashiq %A Kellerer, Wolfgang %A Kirstädter, Andreas %A Köhler, Stefan %A Morper, Hans-Jochen %A Schmid, Matthias %B 1st DFG / NSF Young Researchers Workshop at GEC10 %C San Juan, Puerto Rico %D 2011 %T COntrol and Management of COexisting Networks (COMCON)
• Cost and QoE Optimized Service Provisioning. Jarschel, Michael; Meier, Sebastian; Campowsky, Konrad; Wippel, Hans; Patali, Rohit; Sivakumar, Ashiwan. 1st DFG / NSF Young Researchers Workshop at GEC10, San Juan, Puerto Rico, 2011, March 15.
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  @presentation{info3-talk-2011-428, address = {1st DFG / NSF Young Researchers Workshop at GEC10, San Juan, Puerto Rico}, author = {Jarschel, Michael and Meier, Sebastian and Campowsky, Konrad and Wippel, Hans and Patali, Rohit and Sivakumar, Ashiwan}, keywords = {sys:hidden:presentation}, month = {03}, title = {Cost and QoE Optimized Service Provisioning}, year = 2011 }

  %0 Generic %1 info3-talk-2011-428 %A Jarschel, Michael %A Meier, Sebastian %A Campowsky, Konrad %A Wippel, Hans %A Patali, Rohit %A Sivakumar, Ashiwan %C 1st DFG / NSF Young Researchers Workshop at GEC10, San Juan, Puerto Rico %D 2011 %T Cost and QoE Optimized Service Provisioning
• An Evaluation of QoE in Cloud Gaming Based on Subjective Tests. Jarschel, Michael; Schlosser, Daniel; Scheuring, Sven; Hoßfeld, Tobias. In Workshop on Future Internet and Next Generation Networks (FINGNet-2011). Seoul, Korea, 2011.
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  Cloud Gaming is a new kind of service, which combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users remotely from a data center. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. The end device only needs a broadband internet connection and the ability to display High Definition (HD) video. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for service quality in terms of bandwidth and latency for the underlying network. In this paper we present the results of a subjective user study we conducted into the user-perceived quality of experience (QoE) in Cloud Gaming. We design a measurement environment, that emulates this new type of service, define tests for users to assess the QoE, derive Key Influence Factors (KFI) and influences of content and perception from our results.

  @inproceedings{info3-inproceedings-2011-411, abstract = {Cloud Gaming is a new kind of service, which combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users remotely from a data center. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. The end device only needs a broadband internet connection and the ability to display High Definition (HD) video. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for service quality in terms of bandwidth and latency for the underlying network. In this paper we present the results of a subjective user study we conducted into the user-perceived quality of experience (QoE) in Cloud Gaming. We design a measurement environment, that emulates this new type of service, define tests for users to assess the QoE, derive Key Influence Factors (KFI) and influences of content and perception from our results.}, address = {Seoul, Korea}, author = {Jarschel, Michael and Schlosser, Daniel and Scheuring, Sven and Hoßfeld, Tobias}, booktitle = {Workshop on Future Internet and Next Generation Networks (FINGNet-2011)}, keywords = {sys:hidden:inproceedings}, month = {06}, title = {An Evaluation of QoE in Cloud Gaming Based on Subjective Tests}, year = 2011 }

  %0 Conference Paper %1 info3-inproceedings-2011-411 %A Jarschel, Michael %A Schlosser, Daniel %A Scheuring, Sven %A Hoßfeld, Tobias %B Workshop on Future Internet and Next Generation Networks (FINGNet-2011) %C Seoul, Korea %D 2011 %T An Evaluation of QoE in Cloud Gaming Based on Subjective Tests %X Cloud Gaming is a new kind of service, which combines the successful concepts of Cloud Computing and Online Gaming. It provides the entire game experience to the users remotely from a data center. The player is no longer dependent on a specific type or quality of gaming hardware, but is able to use common devices. The end device only needs a broadband internet connection and the ability to display High Definition (HD) video. While this may reduce hardware costs for users and increase the revenue for developers by leaving out the retail chain, it also raises new challenges for service quality in terms of bandwidth and latency for the underlying network. In this paper we present the results of a subjective user study we conducted into the user-perceived quality of experience (QoE) in Cloud Gaming. We design a measurement environment, that emulates this new type of service, define tests for users to assess the QoE, derive Key Influence Factors (KFI) and influences of content and perception from our results.
• Modeling and Performance Evaluation of an OpenFlow Architecture. Jarschel, Michael; Oechsner, Simon; Schlosser, Daniel; Pries, Rastin; Goll, Sebastian; Tran-Gia, Phuoc. 23rd International Teletraffic Congress (ITC 2011), San Francisco, CA, USA, 2011, September 6.
  • [ BibTeX ]
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  @presentation{info3-talk-2011-431, address = {23rd International Teletraffic Congress (ITC 2011), San Francisco, CA, USA}, author = {Jarschel, Michael and Oechsner, Simon and Schlosser, Daniel and Pries, Rastin and Goll, Sebastian and Tran-Gia, Phuoc}, keywords = {openflow}, month = {09}, title = {Modeling and Performance Evaluation of an OpenFlow Architecture}, year = 2011 }

  %0 Generic %1 info3-talk-2011-431 %A Jarschel, Michael %A Oechsner, Simon %A Schlosser, Daniel %A Pries, Rastin %A Goll, Sebastian %A Tran-Gia, Phuoc %C 23rd International Teletraffic Congress (ITC 2011), San Francisco, CA, USA %D 2011 %T Modeling and Performance Evaluation of an OpenFlow Architecture
• An Evaluation of QoE in Cloud Gaming Based on Subjective Tests. Jarschel, Michael; Schlosser, Daniel; Scheuring, Sven; Hoßfeld, Tobias. Workshop on Future Internet and Next Generation Networks (FINGNet-2011), Seoul, Korea, 2011, July 2.
  • [ BibTeX ]
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  @presentation{info3-talk-2011-426, address = {Workshop on Future Internet and Next Generation Networks (FINGNet-2011), Seoul, Korea}, author = {Jarschel, Michael and Schlosser, Daniel and Scheuring, Sven and Hoßfeld, Tobias}, keywords = {sys:hidden:presentation}, month = {07}, title = {An Evaluation of QoE in Cloud Gaming Based on Subjective Tests}, year = 2011 }

  %0 Generic %1 info3-talk-2011-426 %A Jarschel, Michael %A Schlosser, Daniel %A Scheuring, Sven %A Hoßfeld, Tobias %C Workshop on Future Internet and Next Generation Networks (FINGNet-2011), Seoul, Korea %D 2011 %T An Evaluation of QoE in Cloud Gaming Based on Subjective Tests
• ECODANE - Reducing Energy COnsumption in DAta Center NEtworks based on Traffic Engineering. Thu Huong, Truong; Schlosser, Daniel; Ngoc Nam, Pham; Jarschel, Michael; Huu Thanh, Nguyen; Pries, Rastin. 2011, August.
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  @misc{info3-poster-2011-29, author = {Thu Huong, Truong and Schlosser, Daniel and Ngoc Nam, Pham and Jarschel, Michael and Huu Thanh, Nguyen and Pries, Rastin}, keywords = {sys:hidden:poster}, month = {08}, title = {ECODANE - Reducing Energy COnsumption in DAta Center NEtworks based on Traffic Engineering}, year = 2011 }

  %0 Generic %1 info3-poster-2011-29 %A Thu Huong, Truong %A Schlosser, Daniel %A Ngoc Nam, Pham %A Jarschel, Michael %A Huu Thanh, Nguyen %A Pries, Rastin %D 2011 %T ECODANE - Reducing Energy COnsumption in DAta Center NEtworks based on Traffic Engineering
• Modeling and Performance Evaluation of an OpenFlow Architecture. Jarschel, Michael; Oechsner, Simon; Schlosser, Daniel; Pries, Rastin; Goll, Sebastian; Tran-Gia, Phuoc. In 23rd International Teletraffic Congress (ITC 2011). San Francisco, CA, USA, 2011.
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  The OpenFlow concept of flow-based forwarding and separation of the control plane from the data plane provides a new flexibility in network innovation. While initially used solely in the research domain, OpenFlow is now finding its way into commercial applications. However, this creates new challenges, as questions of OpenFlow scalability and performance have not yet been answered. This paper is a first step towards that goal. Based on measurements of switching times of current OpenFlow hardware, we derive a basic model for the forwarding speed and blocking probability of an OpenFlow switch combined with an OpenFlow controller and validate it using a simulation. This model can be used to estimate the packet sojourn time and the probability of lost packets in such a system and can give hints to developers and researchers on questions how an OpenFlow architecture will perform given certain parameters.

  @inproceedings{info3-inproceedings-2011-423, abstract = {The OpenFlow concept of flow-based forwarding and separation of the control plane from the data plane provides a new flexibility in network innovation. While initially used solely in the research domain, OpenFlow is now finding its way into commercial applications. However, this creates new challenges, as questions of OpenFlow scalability and performance have not yet been answered. This paper is a first step towards that goal. Based on measurements of switching times of current OpenFlow hardware, we derive a basic model for the forwarding speed and blocking probability of an OpenFlow switch combined with an OpenFlow controller and validate it using a simulation. This model can be used to estimate the packet sojourn time and the probability of lost packets in such a system and can give hints to developers and researchers on questions how an OpenFlow architecture will perform given certain parameters.}, address = {San Francisco, CA, USA}, author = {Jarschel, Michael and Oechsner, Simon and Schlosser, Daniel and Pries, Rastin and Goll, Sebastian and Tran-Gia, Phuoc}, booktitle = {23rd International Teletraffic Congress (ITC 2011)}, keywords = {openflow}, month = {09}, title = {Modeling and Performance Evaluation of an OpenFlow Architecture}, year = 2011 }

  %0 Conference Paper %1 info3-inproceedings-2011-423 %A Jarschel, Michael %A Oechsner, Simon %A Schlosser, Daniel %A Pries, Rastin %A Goll, Sebastian %A Tran-Gia, Phuoc %B 23rd International Teletraffic Congress (ITC 2011) %C San Francisco, CA, USA %D 2011 %T Modeling and Performance Evaluation of an OpenFlow Architecture %X The OpenFlow concept of flow-based forwarding and separation of the control plane from the data plane provides a new flexibility in network innovation. While initially used solely in the research domain, OpenFlow is now finding its way into commercial applications. However, this creates new challenges, as questions of OpenFlow scalability and performance have not yet been answered. This paper is a first step towards that goal. Based on measurements of switching times of current OpenFlow hardware, we derive a basic model for the forwarding speed and blocking probability of an OpenFlow switch combined with an OpenFlow controller and validate it using a simulation. This model can be used to estimate the packet sojourn time and the probability of lost packets in such a system and can give hints to developers and researchers on questions how an OpenFlow architecture will perform given certain parameters.
• Power Consumption Analysis of Data Center Architectures. Pries, Rastin; Jarschel, Michael; Schlosser, Daniel; Klopf, Michael; Tran-Gia, Phuoc. In GreenNets. Colmar, France, 2011.
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  The high power consumption of data centers confronts the providers with major challenges. However, not only the servers and the cooling consume a huge amount of energy, but also the data center network architecture makes an important contribution. In this paper, we introduce different data center architectures and compare them regarding their power consumption. The results show that there are some differences which should not be neglected and that with only minor modifications of the architecture, it is possible to save a huge amount of energy.

  @inproceedings{info3-inproceedings-2011-424, abstract = {The high power consumption of data centers confronts the providers with major challenges. However, not only the servers and the cooling consume a huge amount of energy, but also the data center network architecture makes an important contribution. In this paper, we introduce different data center architectures and compare them regarding their power consumption. The results show that there are some differences which should not be neglected and that with only minor modifications of the architecture, it is possible to save a huge amount of energy.}, address = {Colmar, France}, author = {Pries, Rastin and Jarschel, Michael and Schlosser, Daniel and Klopf, Michael and Tran-Gia, Phuoc}, booktitle = {GreenNets}, keywords = {sys:hidden:inproceedings}, month = 10, title = {Power Consumption Analysis of Data Center Architectures}, year = 2011 }

  %0 Conference Paper %1 info3-inproceedings-2011-424 %A Pries, Rastin %A Jarschel, Michael %A Schlosser, Daniel %A Klopf, Michael %A Tran-Gia, Phuoc %B GreenNets %C Colmar, France %D 2011 %T Power Consumption Analysis of Data Center Architectures %X The high power consumption of data centers confronts the providers with major challenges. However, not only the servers and the cooling consume a huge amount of energy, but also the data center network architecture makes an important contribution. In this paper, we introduce different data center architectures and compare them regarding their power consumption. The results show that there are some differences which should not be neglected and that with only minor modifications of the architecture, it is possible to save a huge amount of energy.
• Evaluating OpenFlow Performance using Queueing Models. Jarschel, Michael; Klein, Dominik. Berlin, Germany, 2011, November.
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  @misc{info3-poster-2011-31, address = {Berlin, Germany}, author = {Jarschel, Michael and Klein, Dominik}, booktitle = {CHANGE & OFELIA Summer School}, keywords = {sys:hidden:poster}, month = 11, title = {Evaluating OpenFlow Performance using Queueing Models}, year = 2011 }

  %0 Generic %1 info3-poster-2011-31 %A Jarschel, Michael %A Klein, Dominik %B CHANGE & OFELIA Summer School %C Berlin, Germany %D 2011 %T Evaluating OpenFlow Performance using Queueing Models

• A Use Case Driven Approach to Network Virtualization. Schlosser, Daniel; Jarschel, Michael; Duelli, Michael; Hoßfeld, Tobias; Hoffmann, Klaus; Hoffmann, Marco; Jochen Morper, Hans; Jurca, Dan; Khan, Ashiq. In accepted at IEEE Kaleidoscope 2010, published via OPUS Würzburg under OpenAccess. Würzburg, 2010.
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  In today's Internet, services are very different in their requirements on the underlying transport network. In the future, this diversity will increase and it will be more difficult to accommodate all services in a single network. A possible approach to cope with this diversity within future networks is the introduction of support for running isolated networks for different services on top of a single shared physical substrate. This would also enable easy network management and ensure an economically sound operation. End-customers will readily adopt this approach as it enables new and innovative services without being expensive. In order to arrive at a concept that enables this kind of network, it needs to be designed around and constantly checked against realistic use cases. In this contribution, we present three use cases for future networks. We describe functional blocks of a virtual network architecture, which are necessary to support these use cases within the network. Furthermore, we discuss the interfaces needed between the functional blocks and consider standardization issues that arise in order to achieve a global consistent control and management structure of virtual networks.

  @inproceedings{info3-inproceedings-2010-412, abstract = {In today's Internet, services are very different in their requirements on the underlying transport network. In the future, this diversity will increase and it will be more difficult to accommodate all services in a single network. A possible approach to cope with this diversity within future networks is the introduction of support for running isolated networks for different services on top of a single shared physical substrate. This would also enable easy network management and ensure an economically sound operation. End-customers will readily adopt this approach as it enables new and innovative services without being expensive. In order to arrive at a concept that enables this kind of network, it needs to be designed around and constantly checked against realistic use cases. In this contribution, we present three use cases for future networks. We describe functional blocks of a virtual network architecture, which are necessary to support these use cases within the network. Furthermore, we discuss the interfaces needed between the functional blocks and consider standardization issues that arise in order to achieve a global consistent control and management structure of virtual networks.}, address = {Würzburg}, author = {Schlosser, Daniel and Jarschel, Michael and Duelli, Michael and Hoßfeld, Tobias and Hoffmann, Klaus and Hoffmann, Marco and Jochen Morper, Hans and Jurca, Dan and Khan, Ashiq}, booktitle = {accepted at IEEE Kaleidoscope 2010, published via OPUS Würzburg under OpenAccess}, keywords = {sys:hidden:inproceedings}, month = 12, title = {A Use Case Driven Approach to Network Virtualization}, year = 2010 }

  %0 Conference Paper %1 info3-inproceedings-2010-412 %A Schlosser, Daniel %A Jarschel, Michael %A Duelli, Michael %A Hoßfeld, Tobias %A Hoffmann, Klaus %A Hoffmann, Marco %A Jochen Morper, Hans %A Jurca, Dan %A Khan, Ashiq %B accepted at IEEE Kaleidoscope 2010, published via OPUS Würzburg under OpenAccess %C Würzburg %D 2010 %T A Use Case Driven Approach to Network Virtualization %X In today's Internet, services are very different in their requirements on the underlying transport network. In the future, this diversity will increase and it will be more difficult to accommodate all services in a single network. A possible approach to cope with this diversity within future networks is the introduction of support for running isolated networks for different services on top of a single shared physical substrate. This would also enable easy network management and ensure an economically sound operation. End-customers will readily adopt this approach as it enables new and innovative services without being expensive. In order to arrive at a concept that enables this kind of network, it needs to be designed around and constantly checked against realistic use cases. In this contribution, we present three use cases for future networks. We describe functional blocks of a virtual network architecture, which are necessary to support these use cases within the network. Furthermore, we discuss the interfaces needed between the functional blocks and consider standardization issues that arise in order to achieve a global consistent control and management structure of virtual networks.
• Network Virtualization: Isolation Problems and Scalability Issues. Schlosser, Daniel; Jarschel, Michael. 6. GI/ITG KuVS Fachgespräch Future Internet, Hannover, Germany, 2010, November 22.
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  @presentation{info3-talk-2010-405, address = {6. GI/ITG KuVS Fachgespräch Future Internet, Hannover, Germany}, author = {Schlosser, Daniel and Jarschel, Michael}, keywords = {sys:hidden:presentation}, month = 11, title = {Network Virtualization: Isolation Problems and Scalability Issues}, year = 2010 }

  %0 Generic %1 info3-talk-2010-405 %A Schlosser, Daniel %A Jarschel, Michael %C 6. GI/ITG KuVS Fachgespräch Future Internet, Hannover, Germany %D 2010 %T Network Virtualization: Isolation Problems and Scalability Issues
• Monitoring the User Perceived Quality of SILK-Based Voice Calls. Schlosser, Daniel; Jarschel, Michael; Burger, Valentin; Pries, Rastin. In Australasian Telecommunication Networks and Applications Conference (ATNAC 2010). Auckland, New Zealand, 2010.
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  Quality measurements are required to support VoIP traffic in the Internet. The widely used average Mean Opinion Score is, however, not sufficient for this task. In this paper, we provide a detailed analysis of the Skype SILK codec and compare it with the iLBC and GSM codec. The results show that the SILK codec is superior to the other codecs in scenarios with random and bulk packet loss. This increased tolerance of packet loss enables the option of QoE Monitoring under reasonable network conditions. From analysis, we derive an estimation, which can be used to monitor the MOS value of the users in the worst case. Furthermore, we show how sampling can effectively decrease the required measurement effort. This work was funded by the Federal Ministry of Education and Research of the Federal Republic of Germany (Förderkennzeichen 01BK0917, GLab). The authors alone are responsible for the content of the paper.

  @inproceedings{info3-inproceedings-2010-399, abstract = {Quality measurements are required to support VoIP traffic in the Internet. The widely used average Mean Opinion Score is, however, not sufficient for this task. In this paper, we provide a detailed analysis of the Skype SILK codec and compare it with the iLBC and GSM codec. The results show that the SILK codec is superior to the other codecs in scenarios with random and bulk packet loss. This increased tolerance of packet loss enables the option of QoE Monitoring under reasonable network conditions. From analysis, we derive an estimation, which can be used to monitor the MOS value of the users in the worst case. Furthermore, we show how sampling can effectively decrease the required measurement effort. This work was funded by the Federal Ministry of Education and Research of the Federal Republic of Germany (Förderkennzeichen 01BK0917, GLab). The authors alone are responsible for the content of the paper.}, address = {Auckland, New Zealand}, author = {Schlosser, Daniel and Jarschel, Michael and Burger, Valentin and Pries, Rastin}, booktitle = {Australasian Telecommunication Networks and Applications Conference (ATNAC 2010)}, keywords = {sys:hidden:inproceedings}, month = 11, title = {Monitoring the User Perceived Quality of SILK-Based Voice Calls}, year = 2010 }

  %0 Conference Paper %1 info3-inproceedings-2010-399 %A Schlosser, Daniel %A Jarschel, Michael %A Burger, Valentin %A Pries, Rastin %B Australasian Telecommunication Networks and Applications Conference (ATNAC 2010) %C Auckland, New Zealand %D 2010 %T Monitoring the User Perceived Quality of SILK-Based Voice Calls %X Quality measurements are required to support VoIP traffic in the Internet. The widely used average Mean Opinion Score is, however, not sufficient for this task. In this paper, we provide a detailed analysis of the Skype SILK codec and compare it with the iLBC and GSM codec. The results show that the SILK codec is superior to the other codecs in scenarios with random and bulk packet loss. This increased tolerance of packet loss enables the option of QoE Monitoring under reasonable network conditions. From analysis, we derive an estimation, which can be used to monitor the MOS value of the users in the worst case. Furthermore, we show how sampling can effectively decrease the required measurement effort. This work was funded by the Federal Ministry of Education and Research of the Federal Republic of Germany (Förderkennzeichen 01BK0917, GLab). The authors alone are responsible for the content of the paper.
• COMCON: Use Cases for Virtual Future Networks. Jarschel, Michael; Kirstädter, Andreas; Kellerer, Wolfgang; Hoffmann, Marco; Hoßfeld, Tobias; Köhler, Stefan; Schlosser, Daniel. In TridentCom 2010. Berlin, 2010.
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  In the Future Internet, a multitude of networks will coexist and complement each other. These networks allow specialization but require isolation of functionalities in order to provide dependable and predictable networks. This allows different networks to run in parallel but isolated from each other. Additionally, network resource scalability is supported to reduce the time and overhead required to introduce new services. The objective of the COMCON (COntrol and Management of COexisting Networks) project is to design novel control and management mechanisms that support the coexistence of networks in a future networking scenario and to illustrate the economic advantages. In this contribution we present three use cases defined in COMCON, which serve as a guideline for our virtual network architecture.

  @inproceedings{info3-inproceedings-2010-383, abstract = {In the Future Internet, a multitude of networks will coexist and complement each other. These networks allow specialization but require isolation of functionalities in order to provide dependable and predictable networks. This allows different networks to run in parallel but isolated from each other. Additionally, network resource scalability is supported to reduce the time and overhead required to introduce new services. The objective of the COMCON (COntrol and Management of COexisting Networks) project is to design novel control and management mechanisms that support the coexistence of networks in a future networking scenario and to illustrate the economic advantages. In this contribution we present three use cases defined in COMCON, which serve as a guideline for our virtual network architecture.}, address = {Berlin}, author = {Jarschel, Michael and Kirstädter, Andreas and Kellerer, Wolfgang and Hoffmann, Marco and Hoßfeld, Tobias and Köhler, Stefan and Schlosser, Daniel}, booktitle = {TridentCom 2010}, keywords = {sys:hidden:inproceedings}, month = {05}, title = {COMCON: Use Cases for Virtual Future Networks}, year = 2010 }

  %0 Conference Paper %1 info3-inproceedings-2010-383 %A Jarschel, Michael %A Kirstädter, Andreas %A Kellerer, Wolfgang %A Hoffmann, Marco %A Hoßfeld, Tobias %A Köhler, Stefan %A Schlosser, Daniel %B TridentCom 2010 %C Berlin %D 2010 %T COMCON: Use Cases for Virtual Future Networks %X In the Future Internet, a multitude of networks will coexist and complement each other. These networks allow specialization but require isolation of functionalities in order to provide dependable and predictable networks. This allows different networks to run in parallel but isolated from each other. Additionally, network resource scalability is supported to reduce the time and overhead required to introduce new services. The objective of the COMCON (COntrol and Management of COexisting Networks) project is to design novel control and management mechanisms that support the coexistence of networks in a future networking scenario and to illustrate the economic advantages. In this contribution we present three use cases defined in COMCON, which serve as a guideline for our virtual network architecture.
• Towards Network Virtualization using OpenFlow Switches. Jarschel, Michael; Hoßfeld, Tobias. ITG FG521 Workshop: Technik und Grenzen der Virtualisierung, Hamburg-Harburg, Germany, 2010, April 23.
  • [ BibTeX ]
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  @presentation{info3-talk-2010-372, address = {ITG FG521 Workshop: Technik und Grenzen der Virtualisierung, Hamburg-Harburg, Germany}, author = {Jarschel, Michael and Hoßfeld, Tobias}, keywords = {sys:hidden:presentation}, month = {04}, title = {Towards Network Virtualization using OpenFlow Switches}, year = 2010 }

  %0 Generic %1 info3-talk-2010-372 %A Jarschel, Michael %A Hoßfeld, Tobias %C ITG FG521 Workshop: Technik und Grenzen der Virtualisierung, Hamburg-Harburg, Germany %D 2010 %T Towards Network Virtualization using OpenFlow Switches
• Open Source Netzwerk Emulatoren. Jarschel, Michael. G-Lab Experimental Facility Workshop, Kaiserslautern, Germany, 2010, March 25.
  • [ BibTeX ]
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  @presentation{info3-talk-2010-427, address = {G-Lab Experimental Facility Workshop, Kaiserslautern, Germany}, author = {Jarschel, Michael}, keywords = {sys:hidden:presentation}, month = {03}, title = {Open Source Netzwerk Emulatoren}, year = 2010 }

  %0 Generic %1 info3-talk-2010-427 %A Jarschel, Michael %C G-Lab Experimental Facility Workshop, Kaiserslautern, Germany %D 2010 %T Open Source Netzwerk Emulatoren