Internet Cloud Architectures

In the area of Internet cloud architectures, we work on national and international projects with different focus. In the following, projects are listed and results are presented.

INPUT project now is in final review

INPUT has been a research project funded by the European Commission under the Horizon 2020 program (Call H2020-ICT-2014-1, Grant no. 644672). The project, started in Juanuary 2015 and ended in December 2017, aims at designing a novel infrastructure and paradigm to support Information Technology (IT) personal cloud services in a scalable and sustainable way and with innovative added-value capabilities.

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QoE Monitoring with VNFs (Virtual Network Functions) in the Cloud

QoE Monitoring VNF is now available at https://go.uniwue.de/qoevnf. The VNF QoE monitoring is a plain software that exploits a C++ library, namely libtins to capture the un-encrypted video flows at network interface. The captured packets are then parsed to feed all necessary information for the video buffer estimation algorithm, such as IP address, TCP header and the payload of application layer protocols.

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Best Demonstration Award IM 2017

The team around Florian Wamser, Frank Loh, Roberto Bruschi, Paolo Lago, Michael Seufert and Phuoc Tran-Gia has won the Best Demonstration Award atInternational Symposium on Integrated Network Management 2017 (IM).

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Current Projects

INPUT (In-Network Programmability for Next-Generation Personal Cloud Service Support, funded by European Commission H2020)

The goal of INPUT is to design a novel edge cloud supported infrastructure for personal cloud services. Within this project, our focus is mainly on monitoring, orchestration, and consolidation algorithms for optimized configuration of network/cloud infrastructure and allocation of virtualized cloud services with respect to energy consumption and Quality of Experience.

After a successful first review in October 2016, we are now right before the final review. The project has fully achieved its objectives and milestones as described in the kick-off meeting in 2015. The project insights can be found at

http://www.input-project.eu

Several demonstration activities are available at

http://www.input-project.eu/index.php/outcomes/demonstration

and objective vs. outcome of the project is available at

http://www.input-project.eu/index.php/outcomes/outcome-vs-objectives

DFG QoE-DZ (Analysis and Optimization of the Trade-off between QoE and Energy-Efficiency in Data Centers)

This project focuses on quantifying and adjusting the trade-off between QoE and energy-efficiency in data centers for highly relevant use cases. An interesting use case for the interconnection between data centers, QoE, and energy-efficiency that is considered to have an increasing impact in the following years, are Virtual Desktop Infrastructures (VDIs). A VDI enables users to use very lightweight systems, e.g., so-called thin clients, whereby the actual operating system including all computations and software runs in a data center.

Related Research Areas

Research Area: QoE Monitoring in the Cloud

The rapid growth of video streaming offers video providers with a great opportunity to increase their revenues, but also presents challenges for the network providers. Network providers are typically not aware of the actual quality experienced by users of video streaming services. As a result, it is difficult for providers to adapt in the network when the QoE is low due to network impairments. To solve this problem, a monitoring mechanism in the network is needed to estimate the QoE perceived by the users.

Publications

Project: EU H2020 INPUT

Impact of VNF Placements on QoE Monitoring in the Cloud. Dinh-Xuan, Lam; Popp, Christian; Burger, Valentin; Wamser, Florian; Hoßfeld, Tobias. In International Journal of Network Management, (NEM-18-0120.R1). 2018.
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@article{info3-article-2018-6, author = {Dinh-Xuan, Lam and Popp, Christian and Burger, Valentin and Wamser, Florian and Hoßfeld, Tobias}, journal = {International Journal of Network Management}, keywords = {video-quality}, month = 10, number = {NEM-18-0120.R1}, title = {Impact of VNF Placements on QoE Monitoring in the Cloud}, year = 2018 }

%0 Journal Article %1 info3-article-2018-6 %A Dinh-Xuan, Lam %A Popp, Christian %A Burger, Valentin %A Wamser, Florian %A Hoßfeld, Tobias %D 2018 %J International Journal of Network Management %N NEM-18-0120.R1 %T Impact of VNF Placements on QoE Monitoring in the Cloud
Quality of Service Assessment of Live Video Streaming with a Remote-Controlled Drone. Loh, Frank; Wamser, Florian; Hoßfeld, Tobias; Tran-Gia, Phuoc. In IEEE Conference on Network Softwarization. Montreal, Canada, 2018.
- [ Abstract ]
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Today's networks require a deep understanding of applications to optimize networks, efficiently design networks, and meet traffic demands, application heterogeneity, and application requirements. Current application areas include live video streaming and real-time applications, such as those that are named in 5G use cases with automation, disaster recovery, gaming, and Industry 4.0. In this work, we examine an application scenario with live video streaming and parallel real-time requirements in the uplink for disaster recovery. We study the quality of service (QoS) features of a remote-controlled drone. The drone is controlled via a tablet or smartphone while the video from the camera is transmitted from the drone to the user. There are high demands in both the uplink and downlink direction. The contribution of the work is the measurement of the QoS and application parameters for this scenario and the definition of influencing parameters for the application-layer.

@inproceedings{info3-inproceedings-2018-31, abstract = {Today's networks require a deep understanding of applications to optimize networks, efficiently design networks, and meet traffic demands, application heterogeneity, and application requirements. Current application areas include live video streaming and real-time applications, such as those that are named in 5G use cases with automation, disaster recovery, gaming, and Industry 4.0. In this work, we examine an application scenario with live video streaming and parallel real-time requirements in the uplink for disaster recovery. We study the quality of service (QoS) features of a remote-controlled drone. The drone is controlled via a tablet or smartphone while the video from the camera is transmitted from the drone to the user. There are high demands in both the uplink and downlink direction. The contribution of the work is the measurement of the QoS and application parameters for this scenario and the definition of influencing parameters for the application-layer.}, address = {Montreal, Canada}, author = {Loh, Frank and Wamser, Florian and Hoßfeld, Tobias and Tran-Gia, Phuoc}, booktitle = {IEEE Conference on Network Softwarization}, keywords = {can}, month = {07}, title = {Quality of Service Assessment of Live Video Streaming with a Remote-Controlled Drone}, year = 2018 }

%0 Conference Paper %1 info3-inproceedings-2018-31 %A Loh, Frank %A Wamser, Florian %A Hoßfeld, Tobias %A Tran-Gia, Phuoc %B IEEE Conference on Network Softwarization %C Montreal, Canada %D 2018 %T Quality of Service Assessment of Live Video Streaming with a Remote-Controlled Drone %X Today's networks require a deep understanding of applications to optimize networks, efficiently design networks, and meet traffic demands, application heterogeneity, and application requirements. Current application areas include live video streaming and real-time applications, such as those that are named in 5G use cases with automation, disaster recovery, gaming, and Industry 4.0. In this work, we examine an application scenario with live video streaming and parallel real-time requirements in the uplink for disaster recovery. We study the quality of service (QoS) features of a remote-controlled drone. The drone is controlled via a tablet or smartphone while the video from the camera is transmitted from the drone to the user. There are high demands in both the uplink and downlink direction. The contribution of the work is the measurement of the QoS and application parameters for this scenario and the definition of influencing parameters for the application-layer.
Orchestration and Monitoring in Fog Computing for Personal Edge Cloud Service Support. Wamser, Florian; Lombardo, Chiara; Vassilakis, Constantinos; Dinh-Xuan, Lam; Lago, Paolo; Bruschi, Roberto; Tran-Gia, Phuoc. In 2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN). 2018.
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@inproceedings{info3-inproceedings-2018-30, author = {Wamser, Florian and Lombardo, Chiara and Vassilakis, Constantinos and Dinh-Xuan, Lam and Lago, Paolo and Bruschi, Roberto and Tran-Gia, Phuoc}, booktitle = {2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN)}, keywords = {can}, month = {06}, title = {Orchestration and Monitoring in Fog Computing for Personal Edge Cloud Service Support}, year = 2018 }

%0 Conference Paper %1 info3-inproceedings-2018-30 %A Wamser, Florian %A Lombardo, Chiara %A Vassilakis, Constantinos %A Dinh-Xuan, Lam %A Lago, Paolo %A Bruschi, Roberto %A Tran-Gia, Phuoc %B 2018 IEEE International Symposium on Local and Metropolitan Area Networks (LANMAN) %D 2018 %T Orchestration and Monitoring in Fog Computing for Personal Edge Cloud Service Support
Performance Assessment of Cloud Migrations from Network and Application Point of View. Iffländer, Lukas; Wamser, Florian; Metter, Christopher; Tran-Gia, Phuoc; Kounev, Samuel. In Proceedings of 9th EAI International Conference on Mobile Networks and Management (MONAMI 2017). Melbourne, Australia, 2017.
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@inproceedings{info3-inproceedings-2017-22, address = {Melbourne, Australia}, author = {Iffländer, Lukas and Wamser, Florian and Metter, Christopher and Tran-Gia, Phuoc and Kounev, Samuel}, booktitle = {Proceedings of 9th EAI International Conference on Mobile Networks and Management (MONAMI 2017)}, keywords = {can}, month = 12, title = {Performance Assessment of Cloud Migrations from Network and Application Point of View}, year = 2017 }

%0 Conference Paper %1 info3-inproceedings-2017-22 %A Iffländer, Lukas %A Wamser, Florian %A Metter, Christopher %A Tran-Gia, Phuoc %A Kounev, Samuel %B Proceedings of 9th EAI International Conference on Mobile Networks and Management (MONAMI 2017) %C Melbourne, Australia %D 2017 %T Performance Assessment of Cloud Migrations from Network and Application Point of View
Performance Evaluation of Video Streaming Service Chains in Softwarized 5G Networks with Task Graph Reduction. Loh, Frank; Burger, Valentin; Wamser, Florian; Tran-Gia, Phuoc; Schembra, Giovanni; Rametta, Corrado. In 29th International Teletraffic Congress (ITC). 2017.
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@inproceedings{info3-inproceedings-2017-18, author = {Loh, Frank and Burger, Valentin and Wamser, Florian and Tran-Gia, Phuoc and Schembra, Giovanni and Rametta, Corrado}, booktitle = {29th International Teletraffic Congress (ITC)}, keywords = {can}, month = {09}, title = {Performance Evaluation of Video Streaming Service Chains in Softwarized 5G Networks with Task Graph Reduction}, year = 2017 }

%0 Conference Paper %1 info3-inproceedings-2017-18 %A Loh, Frank %A Burger, Valentin %A Wamser, Florian %A Tran-Gia, Phuoc %A Schembra, Giovanni %A Rametta, Corrado %B 29th International Teletraffic Congress (ITC) %D 2017 %T Performance Evaluation of Video Streaming Service Chains in Softwarized 5G Networks with Task Graph Reduction
Server and Content Selection for MPEG DASH Video Streaming with Client Information. Wamser, Florian; Höfner, Steffen; Seufert, Michael; Tran-Gia, Phuoc. In ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE). Los Angeles, CA, USA, 2017.
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In HTTP adaptive streaming (HAS), such as MPEG DASH, the video is split into chunks and is available in different quality levels. If the video chunks are stored or cached on different servers to deal with the high load in the network and the Quality of Experience (QoE) requirements of the users, the problem of content selection arises. In this paper, we evaluate client-side algorithms for dynamically selecting an appropriate content server during DASH video streaming. We present three algorithms with which the DASH client itself can determine the most appropriate server based on client-specific metrics, like actual latency or bandwidth to the content servers. We evaluate and discuss the proposed algorithms with respect to the resulting DASH streaming behavior in terms of buffer levels and quality level selection.

@inproceedings{info3-article-2017-3, abstract = {In HTTP adaptive streaming (HAS), such as MPEG DASH, the video is split into chunks and is available in different quality levels. If the video chunks are stored or cached on different servers to deal with the high load in the network and the Quality of Experience (QoE) requirements of the users, the problem of content selection arises. In this paper, we evaluate client-side algorithms for dynamically selecting an appropriate content server during DASH video streaming. We present three algorithms with which the DASH client itself can determine the most appropriate server based on client-specific metrics, like actual latency or bandwidth to the content servers. We evaluate and discuss the proposed algorithms with respect to the resulting DASH streaming behavior in terms of buffer levels and quality level selection.}, address = {Los Angeles, CA, USA}, author = {Wamser, Florian and Höfner, Steffen and Seufert, Michael and Tran-Gia, Phuoc}, booktitle = {ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {can}, month = {08}, title = {Server and Content Selection for MPEG DASH Video Streaming with Client Information}, year = 2017 }

%0 Conference Paper %1 info3-article-2017-3 %A Wamser, Florian %A Höfner, Steffen %A Seufert, Michael %A Tran-Gia, Phuoc %B ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Los Angeles, CA, USA %D 2017 %T Server and Content Selection for MPEG DASH Video Streaming with Client Information %X In HTTP adaptive streaming (HAS), such as MPEG DASH, the video is split into chunks and is available in different quality levels. If the video chunks are stored or cached on different servers to deal with the high load in the network and the Quality of Experience (QoE) requirements of the users, the problem of content selection arises. In this paper, we evaluate client-side algorithms for dynamically selecting an appropriate content server during DASH video streaming. We present three algorithms with which the DASH client itself can determine the most appropriate server based on client-specific metrics, like actual latency or bandwidth to the content servers. We evaluate and discuss the proposed algorithms with respect to the resulting DASH streaming behavior in terms of buffer levels and quality level selection.
EdgeNetworkCloudSim: Placement of Service Chains in Edge Clouds Using NetworkCloudSim. Seufert, Michael; Kamneng Kwam, Brice; Wamser, Florian; Tran-Gia, Phuoc. In 1st IEEE International Workshop on Network Programmability - From the Data Center to the Ground (NetFoG). Bologna, Italy, 2017.
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Edge cloud computing is a trending paradigm, which extends cloud computing by additionally utilizing computing resources at the network edge, e.g., at mobile base stations. Especially personalized services can be instantiated or migrated close to end users, which improves the latency and supports user mobility. However, the placement of the service chains is crucial for the performance of the services and the energy consumption of the edge cloud platform, and appropriate algorithms have to be designed. To support the simulative performance evaluation of such algorithms, EdgeNetworkCloudSim was developed. It is an extension of NetworkCloudSim, and allows to simulate and evaluate the orchestration and consolidation of service chains in an edge network cloud.

@inproceedings{info3-inproceedings-2017-12, abstract = {Edge cloud computing is a trending paradigm, which extends cloud computing by additionally utilizing computing resources at the network edge, e.g., at mobile base stations. Especially personalized services can be instantiated or migrated close to end users, which improves the latency and supports user mobility. However, the placement of the service chains is crucial for the performance of the services and the energy consumption of the edge cloud platform, and appropriate algorithms have to be designed. To support the simulative performance evaluation of such algorithms, EdgeNetworkCloudSim was developed. It is an extension of NetworkCloudSim, and allows to simulate and evaluate the orchestration and consolidation of service chains in an edge network cloud.}, address = {Bologna, Italy}, author = {Seufert, Michael and Kamneng Kwam, Brice and Wamser, Florian and Tran-Gia, Phuoc}, booktitle = {1st IEEE International Workshop on Network Programmability - From the Data Center to the Ground (NetFoG)}, keywords = {can}, month = {07}, title = {EdgeNetworkCloudSim: Placement of Service Chains in Edge Clouds Using NetworkCloudSim}, year = 2017 }

%0 Conference Paper %1 info3-inproceedings-2017-12 %A Seufert, Michael %A Kamneng Kwam, Brice %A Wamser, Florian %A Tran-Gia, Phuoc %B 1st IEEE International Workshop on Network Programmability - From the Data Center to the Ground (NetFoG) %C Bologna, Italy %D 2017 %T EdgeNetworkCloudSim: Placement of Service Chains in Edge Clouds Using NetworkCloudSim %X Edge cloud computing is a trending paradigm, which extends cloud computing by additionally utilizing computing resources at the network edge, e.g., at mobile base stations. Especially personalized services can be instantiated or migrated close to end users, which improves the latency and supports user mobility. However, the placement of the service chains is crucial for the performance of the services and the energy consumption of the edge cloud platform, and appropriate algorithms have to be designed. To support the simulative performance evaluation of such algorithms, EdgeNetworkCloudSim was developed. It is an extension of NetworkCloudSim, and allows to simulate and evaluate the orchestration and consolidation of service chains in an edge network cloud.
Study on the Accuracy of QoE Monitoring for HTTP Adaptive Video Streaming Using VNF. Dinh-Xuan, Lam; Seufert, Michael; Wamser, Florian; Tran-Gia, Phuoc. In 1st IFIP/IEEE International Workshop on Quality of Experience Management (QoE-Management). Lisbon, Portugal, 2017.
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- [ EndNote ]
The fast growth of HTTP video streaming is responsible for a huge amount of traffic over the past few years. Due to the variety and popularity of video content, more and more people are watching videos on the smart TV or on mobile devices. As a result, a potential market is emerging for video providers, which can significantly increase their revenues. In order to offer users a good experience, adaptive video streaming has been introduced to adapt the video quality to the network conditions. Nevertheless, it is still difficult for the network operators to assess the actual video quality on the device of the users and therefore they can not react to improve the service on the network. In this work, we propose a Virtual Network Function (VNF) to monitor the Quality of Experience (QoE) for online video service in the network. To conduct the study, on the one hand, we design a VNF monitoring to measure the video quality and estimate the QoE at the client machine. Our function is placed in two locations nearby and far away from the user to analyze the impact of geographical placement of the VNF on its performance. On the other hand, we set up a local testbed to examine the functional operation and measure the actual video buffer from a client web browser directly to validate the accuracy of the function. Our findings show that with respect to function placement, the VNF has high accuracy in estimating the QoE if it is deployed at the edge network close to the user. However, the VNF does not perform well when it operates far away from the users, e.g., at data centers. These insights help network vendors to more closely monitor the quality of the videos streamed to their customers.

@inproceedings{info3-inproceedings-2017-3, abstract = {The fast growth of HTTP video streaming is responsible for a huge amount of traffic over the past few years. Due to the variety and popularity of video content, more and more people are watching videos on the smart TV or on mobile devices. As a result, a potential market is emerging for video providers, which can significantly increase their revenues. In order to offer users a good experience, adaptive video streaming has been introduced to adapt the video quality to the network conditions. Nevertheless, it is still difficult for the network operators to assess the actual video quality on the device of the users and therefore they can not react to improve the service on the network. In this work, we propose a Virtual Network Function (VNF) to monitor the Quality of Experience (QoE) for online video service in the network. To conduct the study, on the one hand, we design a VNF monitoring to measure the video quality and estimate the QoE at the client machine. Our function is placed in two locations nearby and far away from the user to analyze the impact of geographical placement of the VNF on its performance. On the other hand, we set up a local testbed to examine the functional operation and measure the actual video buffer from a client web browser directly to validate the accuracy of the function. Our findings show that with respect to function placement, the VNF has high accuracy in estimating the QoE if it is deployed at the edge network close to the user. However, the VNF does not perform well when it operates far away from the users, e.g., at data centers. These insights help network vendors to more closely monitor the quality of the videos streamed to their customers.}, address = {Lisbon, Portugal}, author = {Dinh-Xuan, Lam and Seufert, Michael and Wamser, Florian and Tran-Gia, Phuoc}, booktitle = {1st IFIP/IEEE International Workshop on Quality of Experience Management (QoE-Management)}, keywords = {can}, month = {05}, title = {Study on the Accuracy of QoE Monitoring for HTTP Adaptive Video Streaming Using VNF}, year = 2017 }

%0 Conference Paper %1 info3-inproceedings-2017-3 %A Dinh-Xuan, Lam %A Seufert, Michael %A Wamser, Florian %A Tran-Gia, Phuoc %B 1st IFIP/IEEE International Workshop on Quality of Experience Management (QoE-Management) %C Lisbon, Portugal %D 2017 %T Study on the Accuracy of QoE Monitoring for HTTP Adaptive Video Streaming Using VNF %X The fast growth of HTTP video streaming is responsible for a huge amount of traffic over the past few years. Due to the variety and popularity of video content, more and more people are watching videos on the smart TV or on mobile devices. As a result, a potential market is emerging for video providers, which can significantly increase their revenues. In order to offer users a good experience, adaptive video streaming has been introduced to adapt the video quality to the network conditions. Nevertheless, it is still difficult for the network operators to assess the actual video quality on the device of the users and therefore they can not react to improve the service on the network. In this work, we propose a Virtual Network Function (VNF) to monitor the Quality of Experience (QoE) for online video service in the network. To conduct the study, on the one hand, we design a VNF monitoring to measure the video quality and estimate the QoE at the client machine. Our function is placed in two locations nearby and far away from the user to analyze the impact of geographical placement of the VNF on its performance. On the other hand, we set up a local testbed to examine the functional operation and measure the actual video buffer from a client web browser directly to validate the accuracy of the function. Our findings show that with respect to function placement, the VNF has high accuracy in estimating the QoE if it is deployed at the edge network close to the user. However, the VNF does not perform well when it operates far away from the users, e.g., at data centers. These insights help network vendors to more closely monitor the quality of the videos streamed to their customers.
Unsupervised QoE Field Study for Mobile YouTube Video Streaming with YoMoApp. Seufert, Michael; Wehner, Nikolas; Wamser, Florian; Casas, Pedro; D’Alconzo, Alessandro; Tran-Gia, Phuoc. In 9th International Conference on Quality of Multimedia Experience (QoMEX). Erfurt, Germany, 2017.
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YoMoApp (YouTube Monitoring App) is an Android app to monitor mobile YouTube video streaming on both application- and network-layer. Additionally, it allows to collect subjective Quality of Experience (QoE) feedback of end users. During the development of the app, the stable versions of YoMoApp were already available in the Google Play Store, and the app was downloaded, installed, and used on many devices to monitor streaming sessions. As the app was not advertised in special campaigns or used for dedicated QoE studies, the monitored streaming sessions of this period compose the data set of a large unsupervised field study. The collected data set is evaluated to characterize current mobile YouTube streaming on both application and network layers. Furthermore, the problems and methodology to obtain QoE results from such unsupervised field study are discussed together with the actual QoE results. Correlations between QoE factors are investigated, and the QoE of clusters of similar streaming sessions is analyzed.

@inproceedings{info3-inproceedings-2017-9, abstract = {YoMoApp (YouTube Monitoring App) is an Android app to monitor mobile YouTube video streaming on both application- and network-layer. Additionally, it allows to collect subjective Quality of Experience (QoE) feedback of end users. During the development of the app, the stable versions of YoMoApp were already available in the Google Play Store, and the app was downloaded, installed, and used on many devices to monitor streaming sessions. As the app was not advertised in special campaigns or used for dedicated QoE studies, the monitored streaming sessions of this period compose the data set of a large unsupervised field study. The collected data set is evaluated to characterize current mobile YouTube streaming on both application and network layers. Furthermore, the problems and methodology to obtain QoE results from such unsupervised field study are discussed together with the actual QoE results. Correlations between QoE factors are investigated, and the QoE of clusters of similar streaming sessions is analyzed.}, address = {Erfurt, Germany}, author = {Seufert, Michael and Wehner, Nikolas and Wamser, Florian and Casas, Pedro and D'Alconzo, Alessandro and Tran-Gia, Phuoc}, booktitle = {9th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {can}, month = {05}, title = {Unsupervised QoE Field Study for Mobile YouTube Video Streaming with YoMoApp}, year = 2017 }

%0 Conference Paper %1 info3-inproceedings-2017-9 %A Seufert, Michael %A Wehner, Nikolas %A Wamser, Florian %A Casas, Pedro %A D'Alconzo, Alessandro %A Tran-Gia, Phuoc %B 9th International Conference on Quality of Multimedia Experience (QoMEX) %C Erfurt, Germany %D 2017 %T Unsupervised QoE Field Study for Mobile YouTube Video Streaming with YoMoApp %X YoMoApp (YouTube Monitoring App) is an Android app to monitor mobile YouTube video streaming on both application- and network-layer. Additionally, it allows to collect subjective Quality of Experience (QoE) feedback of end users. During the development of the app, the stable versions of YoMoApp were already available in the Google Play Store, and the app was downloaded, installed, and used on many devices to monitor streaming sessions. As the app was not advertised in special campaigns or used for dedicated QoE studies, the monitored streaming sessions of this period compose the data set of a large unsupervised field study. The collected data set is evaluated to characterize current mobile YouTube streaming on both application and network layers. Furthermore, the problems and methodology to obtain QoE results from such unsupervised field study are discussed together with the actual QoE results. Correlations between QoE factors are investigated, and the QoE of clusters of similar streaming sessions is analyzed.
Unperturbed Video Streaming QoE Under Web Page Related Context Factors. Seufert, Michael; Zach, Ondrej; Slanina, Martin; Tran-Gia, Phuoc. In 9th International Conference on Quality of Multimedia Experience (QoMEX). Erfurt, Germany, 2017.
- [ Abstract ]
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- [ EndNote ]
Quality of Experience (QoE) of Internet services is affected by human, system, and context influence factors. While most QoE studies so far are focused on system factors only, this work will assess the impact of context factors of video streaming on QoE. As video streaming is mostly consumed from web pages, such as video portals, the investigated test conditions are applied to the web page, which embeds the video player. Therefore, the study of context factors is implicitly conducted within a crowdsourced QoE study. The test conditions considered different page load times, poster image qualities, and displayed advertisements on the web page, which are typical context factors when consuming a video streaming service. The results of the study show that the modification of the context factors on the streaming web page leaves the users' QoE rating unperturbed, which suggests that the investigated context factors have a negligible impact on video streaming QoE, or that the rating task of the subjective QoE study superimposed the context factors.

@inproceedings{info3-inproceedings-2017-11, abstract = {Quality of Experience (QoE) of Internet services is affected by human, system, and context influence factors. While most QoE studies so far are focused on system factors only, this work will assess the impact of context factors of video streaming on QoE. As video streaming is mostly consumed from web pages, such as video portals, the investigated test conditions are applied to the web page, which embeds the video player. Therefore, the study of context factors is implicitly conducted within a crowdsourced QoE study. The test conditions considered different page load times, poster image qualities, and displayed advertisements on the web page, which are typical context factors when consuming a video streaming service. The results of the study show that the modification of the context factors on the streaming web page leaves the users' QoE rating unperturbed, which suggests that the investigated context factors have a negligible impact on video streaming QoE, or that the rating task of the subjective QoE study superimposed the context factors.}, address = {Erfurt, Germany}, author = {Seufert, Michael and Zach, Ondrej and Slanina, Martin and Tran-Gia, Phuoc}, booktitle = {9th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {can}, month = {05}, title = {Unperturbed Video Streaming QoE Under Web Page Related Context Factors}, year = 2017 }

%0 Conference Paper %1 info3-inproceedings-2017-11 %A Seufert, Michael %A Zach, Ondrej %A Slanina, Martin %A Tran-Gia, Phuoc %B 9th International Conference on Quality of Multimedia Experience (QoMEX) %C Erfurt, Germany %D 2017 %T Unperturbed Video Streaming QoE Under Web Page Related Context Factors %X Quality of Experience (QoE) of Internet services is affected by human, system, and context influence factors. While most QoE studies so far are focused on system factors only, this work will assess the impact of context factors of video streaming on QoE. As video streaming is mostly consumed from web pages, such as video portals, the investigated test conditions are applied to the web page, which embeds the video player. Therefore, the study of context factors is implicitly conducted within a crowdsourced QoE study. The test conditions considered different page load times, poster image qualities, and displayed advertisements on the web page, which are typical context factors when consuming a video streaming service. The results of the study show that the modification of the context factors on the streaming web page leaves the users' QoE rating unperturbed, which suggests that the investigated context factors have a negligible impact on video streaming QoE, or that the rating task of the subjective QoE study superimposed the context factors.
Dynamic Cloud Service Placement for Live Video Streaming with a Remote-Controlled Drone. Wamser, Florian; Loh, Frank; Bruschi, Roberto; Lago, Paolo; Seufert, Michael; Tran-Gia, Phuoc. Best Demo Award, Lisbon, Portugal, 2017, May.
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- [ EndNote ]
The continuous growth of Internet content, applications and services has led to ever more demanding requirements in the networks. To meet this, there have been significant developments in the migration of applications and services towards the cloud. The cloud not only provides applications, but also offers dynamic adaptability, scalability, and optimization with respect to the location of the application by migrating storage and application containers. In particular, cloud services can typically be placed and orchestrated at a variety of locations in the cloud. This demonstration shows a dynamic placement of a cloud service with video streaming and real-time control commands for a remote-controlled drone. We control a drone with the help of a cloud service which, in addition to the control commands, also returns a camera image to the operator. The requirements of this cloud application are groundbreaking. The camera requires high data rates from the drone to the cloud and from the cloud to the operator, so that the image can be transmitted in acceptable quality. For the control of the drone, a short delay must also be given in the direction of the drone so that the control can be carried out in real time.

@misc{info3-demo-2017-1, abstract = {The continuous growth of Internet content, applications and services has led to ever more demanding requirements in the networks. To meet this, there have been significant developments in the migration of applications and services towards the cloud. The cloud not only provides applications, but also offers dynamic adaptability, scalability, and optimization with respect to the location of the application by migrating storage and application containers. In particular, cloud services can typically be placed and orchestrated at a variety of locations in the cloud. This demonstration shows a dynamic placement of a cloud service with video streaming and real-time control commands for a remote-controlled drone. We control a drone with the help of a cloud service which, in addition to the control commands, also returns a camera image to the operator. The requirements of this cloud application are groundbreaking. The camera requires high data rates from the drone to the cloud and from the cloud to the operator, so that the image can be transmitted in acceptable quality. For the control of the drone, a short delay must also be given in the direction of the drone so that the control can be carried out in real time.}, address = {Best Demo Award, Lisbon, Portugal}, author = {Wamser, Florian and Loh, Frank and Bruschi, Roberto and Lago, Paolo and Seufert, Michael and Tran-Gia, Phuoc}, booktitle = {15th IFIP/IEEE International Symposium on Integrated Network Management (IM)}, keywords = {can}, month = {05}, title = {Dynamic Cloud Service Placement for Live Video Streaming with a Remote-Controlled Drone}, year = 2017 }

%0 Generic %1 info3-demo-2017-1 %A Wamser, Florian %A Loh, Frank %A Bruschi, Roberto %A Lago, Paolo %A Seufert, Michael %A Tran-Gia, Phuoc %B 15th IFIP/IEEE International Symposium on Integrated Network Management (IM) %C Best Demo Award, Lisbon, Portugal %D 2017 %T Dynamic Cloud Service Placement for Live Video Streaming with a Remote-Controlled Drone %X The continuous growth of Internet content, applications and services has led to ever more demanding requirements in the networks. To meet this, there have been significant developments in the migration of applications and services towards the cloud. The cloud not only provides applications, but also offers dynamic adaptability, scalability, and optimization with respect to the location of the application by migrating storage and application containers. In particular, cloud services can typically be placed and orchestrated at a variety of locations in the cloud. This demonstration shows a dynamic placement of a cloud service with video streaming and real-time control commands for a remote-controlled drone. We control a drone with the help of a cloud service which, in addition to the control commands, also returns a camera image to the operator. The requirements of this cloud application are groundbreaking. The camera requires high data rates from the drone to the cloud and from the cloud to the operator, so that the image can be transmitted in acceptable quality. For the control of the drone, a short delay must also be given in the direction of the drone so that the control can be carried out in real time.
Modeling the YouTube Stack: from Packets to Quality of Experience. Wamser, Florian; Casas, Pedro; Seufert, Michael; Moldovan, Christian; Tran-Gia, Phuoc; Hoßfeld, Tobias. In Computer Networks, 109(2), pp. 211–224. 2016.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
YouTube is one of the most popular and volume-dominant services in today’s Internet, and has changed the Web for ever. Consequently, network operators are forced to consider it in the design, deployment, and optimization of their networks. Taming YouTube requires a good understanding of the complete YouTube stack, from the network streaming service to the application itself. Understanding the interplays between individual YouTube functionalities and their implications for traffic and user Quality of Experience (QoE) becomes paramount nowadays. In this paper we characterize and model the YouTube stack at different layers, going from the generated network traffic to the QoE perceived by the users watching YouTube videos. Firstly, we present a network traffic model for the YouTube flow control mechanism, which permits to understand how YouTube provisions video traffic flows to users. Secondly, we investigate how traffic is consumed at the client side, deriving a simple model for the YouTube application. Thirdly, we analyze the implications for the end user, and present a model for the quality as perceived by them. This model is finally integrated into a system for real time QoE-based YouTube monitoring, highly useful to operators to assess the performance of their networks for provisioning YouTube videos. The central parameter for all the presented models is the buffer level at the YouTube application layer. This paper provides an extensive compendium of objective tools and models for network operators to better understand the YouTube traffic in their networks, to predict the playback behavior of the video player, and to assess how well they do it in the practice with the satisfaction of their customers watching YouTube.

@article{info3-article-2016-6, abstract = {YouTube is one of the most popular and volume-dominant services in today’s Internet, and has changed the Web for ever. Consequently, network operators are forced to consider it in the design, deployment, and optimization of their networks. Taming YouTube requires a good understanding of the complete YouTube stack, from the network streaming service to the application itself. Understanding the interplays between individual YouTube functionalities and their implications for traffic and user Quality of Experience (QoE) becomes paramount nowadays. In this paper we characterize and model the YouTube stack at different layers, going from the generated network traffic to the QoE perceived by the users watching YouTube videos. Firstly, we present a network traffic model for the YouTube flow control mechanism, which permits to understand how YouTube provisions video traffic flows to users. Secondly, we investigate how traffic is consumed at the client side, deriving a simple model for the YouTube application. Thirdly, we analyze the implications for the end user, and present a model for the quality as perceived by them. This model is finally integrated into a system for real time QoE-based YouTube monitoring, highly useful to operators to assess the performance of their networks for provisioning YouTube videos. The central parameter for all the presented models is the buffer level at the YouTube application layer. This paper provides an extensive compendium of objective tools and models for network operators to better understand the YouTube traffic in their networks, to predict the playback behavior of the video player, and to assess how well they do it in the practice with the satisfaction of their customers watching YouTube.}, author = {Wamser, Florian and Casas, Pedro and Seufert, Michael and Moldovan, Christian and Tran-Gia, Phuoc and Hoßfeld, Tobias}, journal = {Computer Networks}, keywords = {can}, month = 11, number = 2, pages = {211-224}, title = {Modeling the YouTube Stack: from Packets to Quality of Experience}, volume = 109, year = 2016 }

%0 Journal Article %1 info3-article-2016-6 %A Wamser, Florian %A Casas, Pedro %A Seufert, Michael %A Moldovan, Christian %A Tran-Gia, Phuoc %A Hoßfeld, Tobias %D 2016 %J Computer Networks %N 2 %P 211-224 %T Modeling the YouTube Stack: from Packets to Quality of Experience %V 109 %X YouTube is one of the most popular and volume-dominant services in today’s Internet, and has changed the Web for ever. Consequently, network operators are forced to consider it in the design, deployment, and optimization of their networks. Taming YouTube requires a good understanding of the complete YouTube stack, from the network streaming service to the application itself. Understanding the interplays between individual YouTube functionalities and their implications for traffic and user Quality of Experience (QoE) becomes paramount nowadays. In this paper we characterize and model the YouTube stack at different layers, going from the generated network traffic to the QoE perceived by the users watching YouTube videos. Firstly, we present a network traffic model for the YouTube flow control mechanism, which permits to understand how YouTube provisions video traffic flows to users. Secondly, we investigate how traffic is consumed at the client side, deriving a simple model for the YouTube application. Thirdly, we analyze the implications for the end user, and present a model for the quality as perceived by them. This model is finally integrated into a system for real time QoE-based YouTube monitoring, highly useful to operators to assess the performance of their networks for provisioning YouTube videos. The central parameter for all the presented models is the buffer level at the YouTube application layer. This paper provides an extensive compendium of objective tools and models for network operators to better understand the YouTube traffic in their networks, to predict the playback behavior of the video player, and to assess how well they do it in the practice with the satisfaction of their customers watching YouTube.
Concept for Client-initiated Selection of Cloud Instances for Improving QoE of Distributed Cloud Services. Wamser, Florian; Seufert, Michael; Höfner, Steffen; Tran-Gia, Phuoc. In ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE). Florianópolis, Brazil, 2016.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
We introduce a concept for client-initiated selection of service location and service quality for improving the Quality of Experience (QoE) of general cloud services. It is loosely based on the HTTP adaptive streaming approach (e.g., MPEG DASH). A manifest file compiled by the cloud service provider specifies the available service locations and qualities, from which the user selects the optimal service instance based on contextual information obtained from client measurements and user preferences. The proposed concept is defined and is implemented in two client-based decision algorithms for improving the QoE of a simple picture gallery cloud service. These decision algorithms are evaluated and their impact on the service delivery is discussed. The evaluation shows that it is possible to improve the service location and quality selection by light-weight client-based algorithms.

@inproceedings{info3-inproceedings-2016-14, abstract = {We introduce a concept for client-initiated selection of service location and service quality for improving the Quality of Experience (QoE) of general cloud services. It is loosely based on the HTTP adaptive streaming approach (e.g., MPEG DASH). A manifest file compiled by the cloud service provider specifies the available service locations and qualities, from which the user selects the optimal service instance based on contextual information obtained from client measurements and user preferences. The proposed concept is defined and is implemented in two client-based decision algorithms for improving the QoE of a simple picture gallery cloud service. These decision algorithms are evaluated and their impact on the service delivery is discussed. The evaluation shows that it is possible to improve the service location and quality selection by light-weight client-based algorithms.}, address = {Florianópolis, Brazil}, author = {Wamser, Florian and Seufert, Michael and Höfner, Steffen and Tran-Gia, Phuoc}, booktitle = {ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {can}, month = {08}, title = {Concept for Client-initiated Selection of Cloud Instances for Improving QoE of Distributed Cloud Services}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-14 %A Wamser, Florian %A Seufert, Michael %A Höfner, Steffen %A Tran-Gia, Phuoc %B ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Florianópolis, Brazil %D 2016 %T Concept for Client-initiated Selection of Cloud Instances for Improving QoE of Distributed Cloud Services %X We introduce a concept for client-initiated selection of service location and service quality for improving the Quality of Experience (QoE) of general cloud services. It is loosely based on the HTTP adaptive streaming approach (e.g., MPEG DASH). A manifest file compiled by the cloud service provider specifies the available service locations and qualities, from which the user selects the optimal service instance based on contextual information obtained from client measurements and user preferences. The proposed concept is defined and is implemented in two client-based decision algorithms for improving the QoE of a simple picture gallery cloud service. These decision algorithms are evaluated and their impact on the service delivery is discussed. The evaluation shows that it is possible to improve the service location and quality selection by light-weight client-based algorithms.
QoE Aware Placement of Content in Edge Networks on the Example of a Photo Album Cloud Service. Dinh-Xuan, Lam; Seufert, Michael; Wamser, Florian; Tran-Gia, Phuoc. In IEEE 6th International Conference on Communications and Electronics (ICCE). Ha Long, Vietnam, 2016.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
The paradigm of Software as a Service has gained great achievements in the last decade. By transferring computation and storage to the cloud and migrating services to the edge network, users benefit from using demanding services on lightweight devices. However, the user perceived quality of experience (QoE) for these services is facing the challenges of network impairments and the accessibility of users. Unlike a typical PC-based software, the cloud provides users a location-aware, flexible placement of resource for a cost effective service. The geographical placement of content is therefore one of the key factors that affects the user's satisfaction. The closer the content to the user geographically is, the faster it will be delivered to the user that will also increase the user perceived QoE. In this work, we estimate more precisely the QoE for photo loading time in a particular usage of a photo album cloud service with regard to the influence of various parameters. Firstly, we validate a TCP throughput model and use it to calculate the photo loading time from a given photo size and network QoS. Thereafter, we formulate a mapping function to calculate the MOS value from a QoE model adding the output of the TCP model. From this mapping function, we can estimate QoE for photo loading time from a given photo size, its placement and network QoS. Our main contribution is to determine the trade-off between the size of photo and its placement to acquire a high QoE for photo loading time, which is important for the development of a photo album cloud service.

@inproceedings{info3-inproceedings-2016-16, abstract = {The paradigm of Software as a Service has gained great achievements in the last decade. By transferring computation and storage to the cloud and migrating services to the edge network, users benefit from using demanding services on lightweight devices. However, the user perceived quality of experience (QoE) for these services is facing the challenges of network impairments and the accessibility of users. Unlike a typical PC-based software, the cloud provides users a location-aware, flexible placement of resource for a cost effective service. The geographical placement of content is therefore one of the key factors that affects the user's satisfaction. The closer the content to the user geographically is, the faster it will be delivered to the user that will also increase the user perceived QoE. In this work, we estimate more precisely the QoE for photo loading time in a particular usage of a photo album cloud service with regard to the influence of various parameters. Firstly, we validate a TCP throughput model and use it to calculate the photo loading time from a given photo size and network QoS. Thereafter, we formulate a mapping function to calculate the MOS value from a QoE model adding the output of the TCP model. From this mapping function, we can estimate QoE for photo loading time from a given photo size, its placement and network QoS. Our main contribution is to determine the trade-off between the size of photo and its placement to acquire a high QoE for photo loading time, which is important for the development of a photo album cloud service.}, address = {Ha Long, Vietnam}, author = {Dinh-Xuan, Lam and Seufert, Michael and Wamser, Florian and Tran-Gia, Phuoc}, booktitle = {IEEE 6th International Conference on Communications and Electronics (ICCE)}, keywords = {can}, month = {07}, title = {QoE Aware Placement of Content in Edge Networks on the Example of a Photo Album Cloud Service}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-16 %A Dinh-Xuan, Lam %A Seufert, Michael %A Wamser, Florian %A Tran-Gia, Phuoc %B IEEE 6th International Conference on Communications and Electronics (ICCE) %C Ha Long, Vietnam %D 2016 %T QoE Aware Placement of Content in Edge Networks on the Example of a Photo Album Cloud Service %X The paradigm of Software as a Service has gained great achievements in the last decade. By transferring computation and storage to the cloud and migrating services to the edge network, users benefit from using demanding services on lightweight devices. However, the user perceived quality of experience (QoE) for these services is facing the challenges of network impairments and the accessibility of users. Unlike a typical PC-based software, the cloud provides users a location-aware, flexible placement of resource for a cost effective service. The geographical placement of content is therefore one of the key factors that affects the user's satisfaction. The closer the content to the user geographically is, the faster it will be delivered to the user that will also increase the user perceived QoE. In this work, we estimate more precisely the QoE for photo loading time in a particular usage of a photo album cloud service with regard to the influence of various parameters. Firstly, we validate a TCP throughput model and use it to calculate the photo loading time from a given photo size and network QoS. Thereafter, we formulate a mapping function to calculate the MOS value from a QoE model adding the output of the TCP model. From this mapping function, we can estimate QoE for photo loading time from a given photo size, its placement and network QoS. Our main contribution is to determine the trade-off between the size of photo and its placement to acquire a high QoE for photo loading time, which is important for the development of a photo album cloud service.
Application-Layer Monitoring of QoE Parameters for Mobile YouTube Video Streaming in the Field. Seufert, Michael; Casas, Pedro; Wamser, Florian; Wehner, Nikolas; Schatz, Raimund; Tran-Gia, Phuoc. In IEEE 6th International Conference on Communications and Electronics (ICCE). Ha Long, Vietnam, 2016.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
YouTube video streaming is one of the most popular and most demanding services in cellular networks. Thus, operators are concerned about the quality of the streaming delivered by their networks and would like to monitor the Quality of Experience (QoE) of the end users. In this work, we conduct a field study of mobile YouTube video streaming, in which both network flow parameters and application-layer streaming parameters were monitored, and present the characteristics of current mobile YouTube streaming. The impact of both approaches is investigated showing that monitoring network parameters is not sufficient to directly infer the resulting QoE. In contrast, the streaming parameters, which can be obtained from application-layer monitoring, show high correlations to the subjectively experienced quality, and thus, are better suited for QoE monitoring.

@inproceedings{info3-inproceedings-2016-9, abstract = {YouTube video streaming is one of the most popular and most demanding services in cellular networks. Thus, operators are concerned about the quality of the streaming delivered by their networks and would like to monitor the Quality of Experience (QoE) of the end users. In this work, we conduct a field study of mobile YouTube video streaming, in which both network flow parameters and application-layer streaming parameters were monitored, and present the characteristics of current mobile YouTube streaming. The impact of both approaches is investigated showing that monitoring network parameters is not sufficient to directly infer the resulting QoE. In contrast, the streaming parameters, which can be obtained from application-layer monitoring, show high correlations to the subjectively experienced quality, and thus, are better suited for QoE monitoring.}, address = {Ha Long, Vietnam}, author = {Seufert, Michael and Casas, Pedro and Wamser, Florian and Wehner, Nikolas and Schatz, Raimund and Tran-Gia, Phuoc}, booktitle = {IEEE 6th International Conference on Communications and Electronics (ICCE)}, keywords = {can}, month = {07}, title = {Application-Layer Monitoring of QoE Parameters for Mobile YouTube Video Streaming in the Field}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-9 %A Seufert, Michael %A Casas, Pedro %A Wamser, Florian %A Wehner, Nikolas %A Schatz, Raimund %A Tran-Gia, Phuoc %B IEEE 6th International Conference on Communications and Electronics (ICCE) %C Ha Long, Vietnam %D 2016 %T Application-Layer Monitoring of QoE Parameters for Mobile YouTube Video Streaming in the Field %X YouTube video streaming is one of the most popular and most demanding services in cellular networks. Thus, operators are concerned about the quality of the streaming delivered by their networks and would like to monitor the Quality of Experience (QoE) of the end users. In this work, we conduct a field study of mobile YouTube video streaming, in which both network flow parameters and application-layer streaming parameters were monitored, and present the characteristics of current mobile YouTube streaming. The impact of both approaches is investigated showing that monitoring network parameters is not sufficient to directly infer the resulting QoE. In contrast, the streaming parameters, which can be obtained from application-layer monitoring, show high correlations to the subjectively experienced quality, and thus, are better suited for QoE monitoring.
Load Dynamics of a Multiplayer Online Battle Area and Simulative Assessment of Edge Server Placements. Burger, Valentin; Frances Pajo, Jane; Sanchez, Odnan Ref; Seufert, Michael; Schwartz, Christian; Wamser, Florian; Davoli, Franco; Tran-Gia, Phuoc. In ACM Multimedia Systems Conference (MMSys). Klagenfurt, Austria, 2016.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
Free-to-play models, streaming of games and eSports are reasons for online gaming to grow in popularity recently. On the forefront are multiplayer online battle arenas, which gain high popularity by introducing a competitive format that is easy to access and requires cooperation and team play. These games highly rely on fast reaction of the players, which makes latency the key performance indicator of such applications. To obtain low latency, this paper proposes moving game servers close to players towards the edge of the network. The performance of such mechanism highly depends on the geographic distribution of players. By analyzing match histories and statistics, we develop models for the arrival process and location of game requests. This allows us to evaluate the performance of edge server resource migration policies in an event based simulation. Our results show that a high number of edge servers is preferable compared to few larger edge servers to reduce the latency of players. This supports approaches that allow deploying virtual server instances in the back-haul.

@inproceedings{info3-inproceedings-2016-2, abstract = {Free-to-play models, streaming of games and eSports are reasons for online gaming to grow in popularity recently. On the forefront are multiplayer online battle arenas, which gain high popularity by introducing a competitive format that is easy to access and requires cooperation and team play. These games highly rely on fast reaction of the players, which makes latency the key performance indicator of such applications. To obtain low latency, this paper proposes moving game servers close to players towards the edge of the network. The performance of such mechanism highly depends on the geographic distribution of players. By analyzing match histories and statistics, we develop models for the arrival process and location of game requests. This allows us to evaluate the performance of edge server resource migration policies in an event based simulation. Our results show that a high number of edge servers is preferable compared to few larger edge servers to reduce the latency of players. This supports approaches that allow deploying virtual server instances in the back-haul.}, address = {Klagenfurt, Austria}, author = {Burger, Valentin and Frances Pajo, Jane and Sanchez, Odnan Ref and Seufert, Michael and Schwartz, Christian and Wamser, Florian and Davoli, Franco and Tran-Gia, Phuoc}, booktitle = {ACM Multimedia Systems Conference (MMSys)}, keywords = {can}, month = {05}, title = {Load Dynamics of a Multiplayer Online Battle Area and Simulative Assessment of Edge Server Placements}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-2 %A Burger, Valentin %A Frances Pajo, Jane %A Sanchez, Odnan Ref %A Seufert, Michael %A Schwartz, Christian %A Wamser, Florian %A Davoli, Franco %A Tran-Gia, Phuoc %B ACM Multimedia Systems Conference (MMSys) %C Klagenfurt, Austria %D 2016 %T Load Dynamics of a Multiplayer Online Battle Area and Simulative Assessment of Edge Server Placements %X Free-to-play models, streaming of games and eSports are reasons for online gaming to grow in popularity recently. On the forefront are multiplayer online battle arenas, which gain high popularity by introducing a competitive format that is easy to access and requires cooperation and team play. These games highly rely on fast reaction of the players, which makes latency the key performance indicator of such applications. To obtain low latency, this paper proposes moving game servers close to players towards the edge of the network. The performance of such mechanism highly depends on the geographic distribution of players. By analyzing match histories and statistics, we develop models for the arrival process and location of game requests. This allows us to evaluate the performance of edge server resource migration policies in an event based simulation. Our results show that a high number of edge servers is preferable compared to few larger edge servers to reduce the latency of players. This supports approaches that allow deploying virtual server instances in the back-haul.
Trade-Off between QoE and Operational Cost in Edge Resource Supported Video Streaming. Burger, Valentin; Darzanos, George; Papafili, Ioanna; Seufert, Michael. In 10th International Conference on P2P, Parallel, Grid, Cloud and Internet Computing (3PGCIC). Krakow, Poland, 2015.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
The largest share of today`s consumer Internet traffic is video streaming and its demand on content delivery networks is continuously growing. To cope with the increasing demand of video streaming, recent work proposes mitigating end-user equipment to support content delivery at the edge of the network. The throughput of end-user equipment supporting content delivery is limited by the uplink of the users Internet connection.Especially for video streaming insufficient throughput causes the video to stall and affects the Quality of Experience (QoE) of end-users.To prevent video streams from stalling, we consider a tiered caching architecture, which requests higher tier caches to support content delivery, if the uplink throughput drops below a certain threshold. We conduct a simulative performance evaluation of the mechanism to investigate its impact on the QoE of end-users. Our results show that especially if the upload bandwidth of end-user equipment is low the setting of the threshold has a high impact. This can be used by operators to achieve the desired trade-off between QoE and operational cost for cache resources.

@inproceedings{info3-inproceedings-2015-530, abstract = {The largest share of today`s consumer Internet traffic is video streaming and its demand on content delivery networks is continuously growing. To cope with the increasing demand of video streaming, recent work proposes mitigating end-user equipment to support content delivery at the edge of the network. The throughput of end-user equipment supporting content delivery is limited by the uplink of the users Internet connection.Especially for video streaming insufficient throughput causes the video to stall and affects the Quality of Experience (QoE) of end-users.To prevent video streams from stalling, we consider a tiered caching architecture, which requests higher tier caches to support content delivery, if the uplink throughput drops below a certain threshold. We conduct a simulative performance evaluation of the mechanism to investigate its impact on the QoE of end-users. Our results show that especially if the upload bandwidth of end-user equipment is low the setting of the threshold has a high impact. This can be used by operators to achieve the desired trade-off between QoE and operational cost for cache resources.}, address = {Krakow, Poland}, author = {Burger, Valentin and Darzanos, George and Papafili, Ioanna and Seufert, Michael}, booktitle = {10th International Conference on P2P, Parallel, Grid, Cloud and Internet Computing (3PGCIC)}, keywords = {can}, month = 11, title = {Trade-Off between QoE and Operational Cost in Edge Resource Supported Video Streaming}, year = 2015 }

%0 Conference Paper %1 info3-inproceedings-2015-530 %A Burger, Valentin %A Darzanos, George %A Papafili, Ioanna %A Seufert, Michael %B 10th International Conference on P2P, Parallel, Grid, Cloud and Internet Computing (3PGCIC) %C Krakow, Poland %D 2015 %T Trade-Off between QoE and Operational Cost in Edge Resource Supported Video Streaming %X The largest share of today`s consumer Internet traffic is video streaming and its demand on content delivery networks is continuously growing. To cope with the increasing demand of video streaming, recent work proposes mitigating end-user equipment to support content delivery at the edge of the network. The throughput of end-user equipment supporting content delivery is limited by the uplink of the users Internet connection.Especially for video streaming insufficient throughput causes the video to stall and affects the Quality of Experience (QoE) of end-users.To prevent video streams from stalling, we consider a tiered caching architecture, which requests higher tier caches to support content delivery, if the uplink throughput drops below a certain threshold. We conduct a simulative performance evaluation of the mechanism to investigate its impact on the QoE of end-users. Our results show that especially if the upload bandwidth of end-user equipment is low the setting of the threshold has a high impact. This can be used by operators to achieve the desired trade-off between QoE and operational cost for cache resources.
Utilizing Home Router Caches to Augment CDNs towards Information-Centric Networking. Seufert, Michael; Burger, Valentin; Wamser, Florian; Tran-Gia, Phuoc; Moldovan, Christian; Hoßfeld, Tobias. In European Conference on Networks and Communications (EuCNC). Paris, France, 2015.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
To implement improved Quality of Service (QoS) and Quality of Experience (QoE) management for content-heavy services like video streaming, content has to be moved closer to the edge. The concept of information-centric networking (ICN) would be a prospective enabler but is currently not practically feasible yet. We propose a hierarchical caching architecture utilizing caches on home routers to augment existing content delivery network (CDN) infrastructure. This approach can be implemented via Software-defined Networking (SDN) and brings current CDNs closer towards ICN. Based on a simulation study, we confirm that our approach is able to serve content more locally, which results in QoS and QoE benefits for end users as well as inter-domain traffic savings for network operators.

@inproceedings{info3-inproceedings-2015-514, abstract = {To implement improved Quality of Service (QoS) and Quality of Experience (QoE) management for content-heavy services like video streaming, content has to be moved closer to the edge. The concept of information-centric networking (ICN) would be a prospective enabler but is currently not practically feasible yet. We propose a hierarchical caching architecture utilizing caches on home routers to augment existing content delivery network (CDN) infrastructure. This approach can be implemented via Software-defined Networking (SDN) and brings current CDNs closer towards ICN. Based on a simulation study, we confirm that our approach is able to serve content more locally, which results in QoS and QoE benefits for end users as well as inter-domain traffic savings for network operators.}, address = {Paris, France}, author = {Seufert, Michael and Burger, Valentin and Wamser, Florian and Tran-Gia, Phuoc and Moldovan, Christian and Hoßfeld, Tobias}, booktitle = {European Conference on Networks and Communications (EuCNC)}, keywords = {can}, month = {06}, title = {Utilizing Home Router Caches to Augment CDNs towards Information-Centric Networking}, year = 2015 }

%0 Conference Paper %1 info3-inproceedings-2015-514 %A Seufert, Michael %A Burger, Valentin %A Wamser, Florian %A Tran-Gia, Phuoc %A Moldovan, Christian %A Hoßfeld, Tobias %B European Conference on Networks and Communications (EuCNC) %C Paris, France %D 2015 %T Utilizing Home Router Caches to Augment CDNs towards Information-Centric Networking %X To implement improved Quality of Service (QoS) and Quality of Experience (QoE) management for content-heavy services like video streaming, content has to be moved closer to the edge. The concept of information-centric networking (ICN) would be a prospective enabler but is currently not practically feasible yet. We propose a hierarchical caching architecture utilizing caches on home routers to augment existing content delivery network (CDN) infrastructure. This approach can be implemented via Software-defined Networking (SDN) and brings current CDNs closer towards ICN. Based on a simulation study, we confirm that our approach is able to serve content more locally, which results in QoS and QoE benefits for end users as well as inter-domain traffic savings for network operators.

Project: DFG QoE-DZ

Collecting Subjective Ratings in Enterprise Environments. Borchert, Kathrin; Hirth, Matthias; Zinner, Thomas; Göritz, Anja. In 9th International Conference on Quality of Multimedia Experience (QoMEX). Erfurt, Germany, 2017.
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- [ EndNote ]
- [ Download ]
@inproceedings{info3-inproceedings-2017-14, address = {Erfurt, Germany}, author = {Borchert, Kathrin and Hirth, Matthias and Zinner, Thomas and Göritz, Anja}, booktitle = {9th International Conference on Quality of Multimedia Experience (QoMEX)}, keywords = {ua-net}, month = {05}, title = {Collecting Subjective Ratings in Enterprise Environments}, year = 2017 }

%0 Conference Paper %1 info3-inproceedings-2017-14 %A Borchert, Kathrin %A Hirth, Matthias %A Zinner, Thomas %A Göritz, Anja %B 9th International Conference on Quality of Multimedia Experience (QoMEX) %C Erfurt, Germany %D 2017 %T Collecting Subjective Ratings in Enterprise Environments
Performance Analysis of Hierarchical Caching Systems with Bandwidth Constraints. Burger, Valentin; Zinner, Thomas. In Proceedings of the International Telecommunication Networks and Applications Conference. Dunedin, New Zealand, 2016.
- [ Abstract ]
- [ BibTeX ]
- [ EndNote ]
The vast majority of Internet traffic is carried by content delivery networks. A high potential to bring content even closer to consumers and to reduce energy cost is achieved by the nano data center (NaDa) concept that has been proposed in recent work. In this approach the capacity available on small devices such as home gateways is used to support content delivery in an hierarchical caching system. In this work, we present a method to determine the efficiency of hierarchical content delivery networks with limited bandwidth, such as in the NaDa approach, analytically. We analyze the Internet Census Dataset to assess the number of available devices on autonomous system level. We evaluate the potential of hierarchical cache networks with bandwidth constraints to assist content delivery and determine its limits.

@inproceedings{info3-inproceedings-2016-22, abstract = {The vast majority of Internet traffic is carried by content delivery networks. A high potential to bring content even closer to consumers and to reduce energy cost is achieved by the nano data center (NaDa) concept that has been proposed in recent work. In this approach the capacity available on small devices such as home gateways is used to support content delivery in an hierarchical caching system. In this work, we present a method to determine the efficiency of hierarchical content delivery networks with limited bandwidth, such as in the NaDa approach, analytically. We analyze the Internet Census Dataset to assess the number of available devices on autonomous system level. We evaluate the potential of hierarchical cache networks with bandwidth constraints to assist content delivery and determine its limits.}, address = {Dunedin, New Zealand}, author = {Burger, Valentin and Zinner, Thomas}, booktitle = {Proceedings of the International Telecommunication Networks and Applications Conference}, keywords = {can}, month = 12, title = {Performance Analysis of Hierarchical Caching Systems with Bandwidth Constraints}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-22 %A Burger, Valentin %A Zinner, Thomas %B Proceedings of the International Telecommunication Networks and Applications Conference %C Dunedin, New Zealand %D 2016 %T Performance Analysis of Hierarchical Caching Systems with Bandwidth Constraints %X The vast majority of Internet traffic is carried by content delivery networks. A high potential to bring content even closer to consumers and to reduce energy cost is achieved by the nano data center (NaDa) concept that has been proposed in recent work. In this approach the capacity available on small devices such as home gateways is used to support content delivery in an hierarchical caching system. In this work, we present a method to determine the efficiency of hierarchical content delivery networks with limited bandwidth, such as in the NaDa approach, analytically. We analyze the Internet Census Dataset to assess the number of available devices on autonomous system level. We evaluate the potential of hierarchical cache networks with bandwidth constraints to assist content delivery and determine its limits.
Modeling the YouTube Stack: from Packets to Quality of Experience. Wamser, Florian; Casas, Pedro; Seufert, Michael; Moldovan, Christian; Tran-Gia, Phuoc; Hoßfeld, Tobias. In Computer Networks, 109(2), pp. 211–224. 2016.
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YouTube is one of the most popular and volume-dominant services in today’s Internet, and has changed the Web for ever. Consequently, network operators are forced to consider it in the design, deployment, and optimization of their networks. Taming YouTube requires a good understanding of the complete YouTube stack, from the network streaming service to the application itself. Understanding the interplays between individual YouTube functionalities and their implications for traffic and user Quality of Experience (QoE) becomes paramount nowadays. In this paper we characterize and model the YouTube stack at different layers, going from the generated network traffic to the QoE perceived by the users watching YouTube videos. Firstly, we present a network traffic model for the YouTube flow control mechanism, which permits to understand how YouTube provisions video traffic flows to users. Secondly, we investigate how traffic is consumed at the client side, deriving a simple model for the YouTube application. Thirdly, we analyze the implications for the end user, and present a model for the quality as perceived by them. This model is finally integrated into a system for real time QoE-based YouTube monitoring, highly useful to operators to assess the performance of their networks for provisioning YouTube videos. The central parameter for all the presented models is the buffer level at the YouTube application layer. This paper provides an extensive compendium of objective tools and models for network operators to better understand the YouTube traffic in their networks, to predict the playback behavior of the video player, and to assess how well they do it in the practice with the satisfaction of their customers watching YouTube.

@article{info3-article-2016-6, abstract = {YouTube is one of the most popular and volume-dominant services in today’s Internet, and has changed the Web for ever. Consequently, network operators are forced to consider it in the design, deployment, and optimization of their networks. Taming YouTube requires a good understanding of the complete YouTube stack, from the network streaming service to the application itself. Understanding the interplays between individual YouTube functionalities and their implications for traffic and user Quality of Experience (QoE) becomes paramount nowadays. In this paper we characterize and model the YouTube stack at different layers, going from the generated network traffic to the QoE perceived by the users watching YouTube videos. Firstly, we present a network traffic model for the YouTube flow control mechanism, which permits to understand how YouTube provisions video traffic flows to users. Secondly, we investigate how traffic is consumed at the client side, deriving a simple model for the YouTube application. Thirdly, we analyze the implications for the end user, and present a model for the quality as perceived by them. This model is finally integrated into a system for real time QoE-based YouTube monitoring, highly useful to operators to assess the performance of their networks for provisioning YouTube videos. The central parameter for all the presented models is the buffer level at the YouTube application layer. This paper provides an extensive compendium of objective tools and models for network operators to better understand the YouTube traffic in their networks, to predict the playback behavior of the video player, and to assess how well they do it in the practice with the satisfaction of their customers watching YouTube.}, author = {Wamser, Florian and Casas, Pedro and Seufert, Michael and Moldovan, Christian and Tran-Gia, Phuoc and Hoßfeld, Tobias}, journal = {Computer Networks}, keywords = {can}, month = 11, number = 2, pages = {211-224}, title = {Modeling the YouTube Stack: from Packets to Quality of Experience}, volume = 109, year = 2016 }

%0 Journal Article %1 info3-article-2016-6 %A Wamser, Florian %A Casas, Pedro %A Seufert, Michael %A Moldovan, Christian %A Tran-Gia, Phuoc %A Hoßfeld, Tobias %D 2016 %J Computer Networks %N 2 %P 211-224 %T Modeling the YouTube Stack: from Packets to Quality of Experience %V 109 %X YouTube is one of the most popular and volume-dominant services in today’s Internet, and has changed the Web for ever. Consequently, network operators are forced to consider it in the design, deployment, and optimization of their networks. Taming YouTube requires a good understanding of the complete YouTube stack, from the network streaming service to the application itself. Understanding the interplays between individual YouTube functionalities and their implications for traffic and user Quality of Experience (QoE) becomes paramount nowadays. In this paper we characterize and model the YouTube stack at different layers, going from the generated network traffic to the QoE perceived by the users watching YouTube videos. Firstly, we present a network traffic model for the YouTube flow control mechanism, which permits to understand how YouTube provisions video traffic flows to users. Secondly, we investigate how traffic is consumed at the client side, deriving a simple model for the YouTube application. Thirdly, we analyze the implications for the end user, and present a model for the quality as perceived by them. This model is finally integrated into a system for real time QoE-based YouTube monitoring, highly useful to operators to assess the performance of their networks for provisioning YouTube videos. The central parameter for all the presented models is the buffer level at the YouTube application layer. This paper provides an extensive compendium of objective tools and models for network operators to better understand the YouTube traffic in their networks, to predict the playback behavior of the video player, and to assess how well they do it in the practice with the satisfaction of their customers watching YouTube.
Correlating QoE and Technical Parameters of an SAP System in an Enterprise Environment. Borchert, Kathrin; Hirth, Matthias; Zinner, Thomas; Mocanu, Decebal Constantin. In QCMan IEEE Workshop on QoE centric Management. 2016.
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@inproceedings{info3-inproceedings-2016-15, author = {Borchert, Kathrin and Hirth, Matthias and Zinner, Thomas and Mocanu, Decebal Constantin}, booktitle = {QCMan IEEE Workshop on QoE centric Management}, keywords = {oekonet}, month = {09}, title = {Correlating QoE and Technical Parameters of an SAP System in an Enterprise Environment}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-15 %A Borchert, Kathrin %A Hirth, Matthias %A Zinner, Thomas %A Mocanu, Decebal Constantin %B QCMan IEEE Workshop on QoE centric Management %D 2016 %T Correlating QoE and Technical Parameters of an SAP System in an Enterprise Environment
Assessing the Accuracy of Network Estimations in the DOTA 2 Game Client. Hirth, Matthias; Allendorf, Fabian; Metzger, Florian; Schwartz, Christian. In Workshop on Perceptual Quality of Systems (PQS). Berlin, Germany, 2016.
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Online video games and the subjective quality of player inter- actions with them rely on good network conditions. Almost equally important is a good and timely knowledge of such conditions in order to take proper countermeasures to worsening conditions. To this end, many online video games include components for estimating the current network status. In this paper, we examine the accuracy of those estimations for the popular competitive multiplayer game DOTA 2. Our results show that the game client is capable of performing a good estimation of the delay and packet loss, but only after a rather large initial delay.

@inproceedings{info3-inproceedings-2016-13, abstract = {Online video games and the subjective quality of player inter- actions with them rely on good network conditions. Almost equally important is a good and timely knowledge of such conditions in order to take proper countermeasures to worsening conditions. To this end, many online video games include components for estimating the current network status. In this paper, we examine the accuracy of those estimations for the popular competitive multiplayer game DOTA 2. Our results show that the game client is capable of performing a good estimation of the delay and packet loss, but only after a rather large initial delay.}, address = {Berlin, Germany}, author = {Hirth, Matthias and Allendorf, Fabian and Metzger, Florian and Schwartz, Christian}, booktitle = {Workshop on Perceptual Quality of Systems (PQS)}, keywords = {sys:hidden:inproceedings}, month = {08}, title = {Assessing the Accuracy of Network Estimations in the DOTA 2 Game Client}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-13 %A Hirth, Matthias %A Allendorf, Fabian %A Metzger, Florian %A Schwartz, Christian %B Workshop on Perceptual Quality of Systems (PQS) %C Berlin, Germany %D 2016 %T Assessing the Accuracy of Network Estimations in the DOTA 2 Game Client %X Online video games and the subjective quality of player inter- actions with them rely on good network conditions. Almost equally important is a good and timely knowledge of such conditions in order to take proper countermeasures to worsening conditions. To this end, many online video games include components for estimating the current network status. In this paper, we examine the accuracy of those estimations for the popular competitive multiplayer game DOTA 2. Our results show that the game client is capable of performing a good estimation of the delay and packet loss, but only after a rather large initial delay.
Concept for Client-initiated Selection of Cloud Instances for Improving QoE of Distributed Cloud Services. Wamser, Florian; Seufert, Michael; Höfner, Steffen; Tran-Gia, Phuoc. In ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE). Florianópolis, Brazil, 2016.
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We introduce a concept for client-initiated selection of service location and service quality for improving the Quality of Experience (QoE) of general cloud services. It is loosely based on the HTTP adaptive streaming approach (e.g., MPEG DASH). A manifest file compiled by the cloud service provider specifies the available service locations and qualities, from which the user selects the optimal service instance based on contextual information obtained from client measurements and user preferences. The proposed concept is defined and is implemented in two client-based decision algorithms for improving the QoE of a simple picture gallery cloud service. These decision algorithms are evaluated and their impact on the service delivery is discussed. The evaluation shows that it is possible to improve the service location and quality selection by light-weight client-based algorithms.

@inproceedings{info3-inproceedings-2016-14, abstract = {We introduce a concept for client-initiated selection of service location and service quality for improving the Quality of Experience (QoE) of general cloud services. It is loosely based on the HTTP adaptive streaming approach (e.g., MPEG DASH). A manifest file compiled by the cloud service provider specifies the available service locations and qualities, from which the user selects the optimal service instance based on contextual information obtained from client measurements and user preferences. The proposed concept is defined and is implemented in two client-based decision algorithms for improving the QoE of a simple picture gallery cloud service. These decision algorithms are evaluated and their impact on the service delivery is discussed. The evaluation shows that it is possible to improve the service location and quality selection by light-weight client-based algorithms.}, address = {Florianópolis, Brazil}, author = {Wamser, Florian and Seufert, Michael and Höfner, Steffen and Tran-Gia, Phuoc}, booktitle = {ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE)}, keywords = {can}, month = {08}, title = {Concept for Client-initiated Selection of Cloud Instances for Improving QoE of Distributed Cloud Services}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-14 %A Wamser, Florian %A Seufert, Michael %A Höfner, Steffen %A Tran-Gia, Phuoc %B ACM SIGCOMM Workshop on QoE-based Analysis and Management of Data Communication Networks (Internet-QoE) %C Florianópolis, Brazil %D 2016 %T Concept for Client-initiated Selection of Cloud Instances for Improving QoE of Distributed Cloud Services %X We introduce a concept for client-initiated selection of service location and service quality for improving the Quality of Experience (QoE) of general cloud services. It is loosely based on the HTTP adaptive streaming approach (e.g., MPEG DASH). A manifest file compiled by the cloud service provider specifies the available service locations and qualities, from which the user selects the optimal service instance based on contextual information obtained from client measurements and user preferences. The proposed concept is defined and is implemented in two client-based decision algorithms for improving the QoE of a simple picture gallery cloud service. These decision algorithms are evaluated and their impact on the service delivery is discussed. The evaluation shows that it is possible to improve the service location and quality selection by light-weight client-based algorithms.
ERWIN - Enabling the Reproducible Investigation of WaItiNg Times for Arbitrary Workflows. Zinner, Thomas; Hirth, Matthias; Fischer, Valentin; Hohlfeld, Oliver. In 8th International Conference on Quality of Multimedia Experiene (QoMEX). Lisbon, Portugal, 2016.
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Delay effects can impact the Quality of Experience of interactive systems, which motivates research assessing delay impairments, mostly for web based systems. Current studies follow individual methodologies and typically assesses individual and custom-made web pages, whose construction requires expert knowledge in web technologies. A range of native, non-web applications cannot be easily modified for delay studies. Thus, a generalized methodology for assessing delay impacts for a broad range of applications that is assessable to researchers without (web) development expertise is still missing. This paper con- tributes to this open problem by i) presenting a new methodology for reproducible delay assessments in a broad class of (web-based) systems and ii) presenting an open-source implementation to be used by the community. This methodology particularly aims at making delay assessment available to a broad range of researchers by avoiding programming skills and thus by lowering the barrier for setting-up delay assessments.

@inproceedings{info3-inproceedings-2016-6, abstract = {Delay effects can impact the Quality of Experience of interactive systems, which motivates research assessing delay impairments, mostly for web based systems. Current studies follow individual methodologies and typically assesses individual and custom-made web pages, whose construction requires expert knowledge in web technologies. A range of native, non-web applications cannot be easily modified for delay studies. Thus, a generalized methodology for assessing delay impacts for a broad range of applications that is assessable to researchers without (web) development expertise is still missing. This paper con- tributes to this open problem by i) presenting a new methodology for reproducible delay assessments in a broad class of (web-based) systems and ii) presenting an open-source implementation to be used by the community. This methodology particularly aims at making delay assessment available to a broad range of researchers by avoiding programming skills and thus by lowering the barrier for setting-up delay assessments.}, address = {Lisbon, Portugal}, author = {Zinner, Thomas and Hirth, Matthias and Fischer, Valentin and Hohlfeld, Oliver}, booktitle = {8th International Conference on Quality of Multimedia Experiene (QoMEX)}, keywords = {sys:hidden:inproceedings}, month = {06}, title = {ERWIN - Enabling the Reproducible Investigation of WaItiNg Times for Arbitrary Workflows}, year = 2016 }

%0 Conference Paper %1 info3-inproceedings-2016-6 %A Zinner, Thomas %A Hirth, Matthias %A Fischer, Valentin %A Hohlfeld, Oliver %B 8th International Conference on Quality of Multimedia Experiene (QoMEX) %C Lisbon, Portugal %D 2016 %T ERWIN - Enabling the Reproducible Investigation of WaItiNg Times for Arbitrary Workflows %X Delay effects can impact the Quality of Experience of interactive systems, which motivates research assessing delay impairments, mostly for web based systems. Current studies follow individual methodologies and typically assesses individual and custom-made web pages, whose construction requires expert knowledge in web technologies. A range of native, non-web applications cannot be easily modified for delay studies. Thus, a generalized methodology for assessing delay impacts for a broad range of applications that is assessable to researchers without (web) development expertise is still missing. This paper con- tributes to this open problem by i) presenting a new methodology for reproducible delay assessments in a broad class of (web-based) systems and ii) presenting an open-source implementation to be used by the community. This methodology particularly aims at making delay assessment available to a broad range of researchers by avoiding programming skills and thus by lowering the barrier for setting-up delay assessments.
Text Categorization for Deriving the Application Quality in Enterprises using Ticketing Systems. Zinner, Thomas; Lemmerich, Florian; Schwarzmann, Susanna; Hirth, Matthias; Karg, Peter; Hotho, Andreas. In 17th International Conference on Big Data Analytics and Knowledge Discovery (DaWaK 2015). Valencia, Spain, 2015.
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Today’s enterprise services and business applications are of- ten centralized in a small number of data centers. Employees located at branches and side offices access the computing infrastructure via the internet using thin client architectures. The task to provide a good application quality to the employers using a multitude of different applications and access networks has thus become complex. Enterprises have to be able to identify resource bottlenecks and applications with a poor performance quickly to take appropriate countermeasures and enable a good application quality for their employees. Ticketing systems within an enterprise use large databases for collecting complaints and problems of the users over a long period of time and thus are an interesting starting point to identify performance problems. However, manual categorization of tickets comes with a high workload. In this paper, we analyze in a case study the applicability of supervised learning algorithms for the automatic identification of relevant tickets, i.e., tickets indicating problematic applications. In that regard, we evaluate different classification algorithms using 12,000 manually annotated tickets accumulated in July 2013 at the ticketing system of a nation- wide operating enterprise. In addition to traditional machine learning metrics, we also analyze the performance of the different classifiers on business-relevant metrics.

@inproceedings{info3-inproceedings-2015-517, abstract = {Today’s enterprise services and business applications are of- ten centralized in a small number of data centers. Employees located at branches and side offices access the computing infrastructure via the internet using thin client architectures. The task to provide a good application quality to the employers using a multitude of different applications and access networks has thus become complex. Enterprises have to be able to identify resource bottlenecks and applications with a poor performance quickly to take appropriate countermeasures and enable a good application quality for their employees. Ticketing systems within an enterprise use large databases for collecting complaints and problems of the users over a long period of time and thus are an interesting starting point to identify performance problems. However, manual categorization of tickets comes with a high workload. In this paper, we analyze in a case study the applicability of supervised learning algorithms for the automatic identification of relevant tickets, i.e., tickets indicating problematic applications. In that regard, we evaluate different classification algorithms using 12,000 manually annotated tickets accumulated in July 2013 at the ticketing system of a nation- wide operating enterprise. In addition to traditional machine learning metrics, we also analyze the performance of the different classifiers on business-relevant metrics.}, address = {Valencia, Spain}, author = {Zinner, Thomas and Lemmerich, Florian and Schwarzmann, Susanna and Hirth, Matthias and Karg, Peter and Hotho, Andreas}, booktitle = {17th International Conference on Big Data Analytics and Knowledge Discovery (DaWaK 2015)}, keywords = {sys:hidden:inproceedings}, month = {09}, title = {Text Categorization for Deriving the Application Quality in Enterprises using Ticketing Systems}, year = 2015 }

%0 Conference Paper %1 info3-inproceedings-2015-517 %A Zinner, Thomas %A Lemmerich, Florian %A Schwarzmann, Susanna %A Hirth, Matthias %A Karg, Peter %A Hotho, Andreas %B 17th International Conference on Big Data Analytics and Knowledge Discovery (DaWaK 2015) %C Valencia, Spain %D 2015 %T Text Categorization for Deriving the Application Quality in Enterprises using Ticketing Systems %X Today’s enterprise services and business applications are of- ten centralized in a small number of data centers. Employees located at branches and side offices access the computing infrastructure via the internet using thin client architectures. The task to provide a good application quality to the employers using a multitude of different applications and access networks has thus become complex. Enterprises have to be able to identify resource bottlenecks and applications with a poor performance quickly to take appropriate countermeasures and enable a good application quality for their employees. Ticketing systems within an enterprise use large databases for collecting complaints and problems of the users over a long period of time and thus are an interesting starting point to identify performance problems. However, manual categorization of tickets comes with a high workload. In this paper, we analyze in a case study the applicability of supervised learning algorithms for the automatic identification of relevant tickets, i.e., tickets indicating problematic applications. In that regard, we evaluate different classification algorithms using 12,000 manually annotated tickets accumulated in July 2013 at the ticketing system of a nation- wide operating enterprise. In addition to traditional machine learning metrics, we also analyze the performance of the different classifiers on business-relevant metrics.
Analyzing the Impact of Delay and Packet Loss on Google Docs. Dinh-Xuan, Lam; Schwartz, Christian; Hirth, Matthias; Wamser, Florian; Truong Thu, Huong. In 7th International Conference on Mobile Networks and Management. Santander, Spain, 2015.
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Software as a Service allows end users to use complex soft- ware directly from their browsers, transferring heavy computation to servers in the cloud. One use of this paradigm is word processing, former a classic use cases of Thin-Client computing. Similar to Thin-Client systems, the network parameters are an important influence factor for the cloud application performance. In this paper, we study Google Docs as an example for online word processing tools. We consider a traditional single user scenario as well as a collaborative scenario with two users working on one document simultaneously. We identify multiple relevant sub-processes per scenario as performance metrics and use a testbed to automatically evaluate the performance of Google Docs under varying network parameters. The main contributions of the paper are (1) the quantification of the impact of network parameters such as delay and packet loss on application performance metrics for both scenarios and (2) linear regression models to derive the application performance for giving network parameters.

@inproceedings{info3-inproceedings-2015-522, abstract = {Software as a Service allows end users to use complex soft- ware directly from their browsers, transferring heavy computation to servers in the cloud. One use of this paradigm is word processing, former a classic use cases of Thin-Client computing. Similar to Thin-Client systems, the network parameters are an important influence factor for the cloud application performance. In this paper, we study Google Docs as an example for online word processing tools. We consider a traditional single user scenario as well as a collaborative scenario with two users working on one document simultaneously. We identify multiple relevant sub-processes per scenario as performance metrics and use a testbed to automatically evaluate the performance of Google Docs under varying network parameters. The main contributions of the paper are (1) the quantification of the impact of network parameters such as delay and packet loss on application performance metrics for both scenarios and (2) linear regression models to derive the application performance for giving network parameters.}, address = {Santander, Spain}, author = {Dinh-Xuan, Lam and Schwartz, Christian and Hirth, Matthias and Wamser, Florian and Truong Thu, Huong}, booktitle = {7th International Conference on Mobile Networks and Management}, keywords = {can}, month = {09}, title = {Analyzing the Impact of Delay and Packet Loss on Google Docs}, year = 2015 }

%0 Conference Paper %1 info3-inproceedings-2015-522 %A Dinh-Xuan, Lam %A Schwartz, Christian %A Hirth, Matthias %A Wamser, Florian %A Truong Thu, Huong %B 7th International Conference on Mobile Networks and Management %C Santander, Spain %D 2015 %T Analyzing the Impact of Delay and Packet Loss on Google Docs %X Software as a Service allows end users to use complex soft- ware directly from their browsers, transferring heavy computation to servers in the cloud. One use of this paradigm is word processing, former a classic use cases of Thin-Client computing. Similar to Thin-Client systems, the network parameters are an important influence factor for the cloud application performance. In this paper, we study Google Docs as an example for online word processing tools. We consider a traditional single user scenario as well as a collaborative scenario with two users working on one document simultaneously. We identify multiple relevant sub-processes per scenario as performance metrics and use a testbed to automatically evaluate the performance of Google Docs under varying network parameters. The main contributions of the paper are (1) the quantification of the impact of network parameters such as delay and packet loss on application performance metrics for both scenarios and (2) linear regression models to derive the application performance for giving network parameters.
Deriving the Employee-perceived Application Quality in Enterprise IT Infrastructures using Information from Ticketing Systems. Schwarzmann, Susanna; Zinner, Thomas; Hirth, Matthias. In Workshop on Knowledge Discovery, Data Mining and Machine Learning (KDML 2014). Aachen, Germany, 2014.
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@inproceedings{info3-inproceedings-2014-502, address = {Aachen, Germany}, author = {Schwarzmann, Susanna and Zinner, Thomas and Hirth, Matthias}, booktitle = {Workshop on Knowledge Discovery, Data Mining and Machine Learning (KDML 2014)}, keywords = {sys:hidden:inproceedings}, month = {09}, title = {Deriving the Employee-perceived Application Quality in Enterprise IT Infrastructures using Information from Ticketing Systems}, year = 2014 }

%0 Conference Paper %1 info3-inproceedings-2014-502 %A Schwarzmann, Susanna %A Zinner, Thomas %A Hirth, Matthias %B Workshop on Knowledge Discovery, Data Mining and Machine Learning (KDML 2014) %C Aachen, Germany %D 2014 %T Deriving the Employee-perceived Application Quality in Enterprise IT Infrastructures using Information from Ticketing Systems

Student works and theses

Master's theses:

Bachelor's theses:

Internet Cloud Architectures