Oliver Hohlfeld
Professor, Distributed Systems Group, University of Kassel
Publications
- IPD: Detecting Traffic Ingress Points at ISPs
Conference: ACM SIGCOMM 2024 - Reviewing War: Unconventional User Reviews as a Side Channel to Circumvent Information Controls
Conference: AAAI International Conference on Web and Social Media (ICWSM) 2024
PDF - ProFi: Scalable and Efficient Website Fingerprinting
Journal: IEEE Transactions on Network and Service Management 2023
PDF DOI - An overview of analysis methods and evaluation results for caching strategies
Journal: Computer Networks, Volume 228, June 2023
PDF DOI - Reviewing War: Unconventional User Reviews as a Side Channel to Circumvent Information Controls
TechReport: arXiv:2302.00598 2023
PDF - TSN Scheduler Benchmarking
Conference: IEEE International Conference on Factory Communication Systems 2023
PDF DOI - IXP Scrubber: Learning from Blackholing Traffic for ML-Driven DDoS Detection at Scale
Conference: ACM SIGCOMM 2022
PDF - Data-Driven Study of Long-Term Gaming Experience
Conference: IEEE Conference on Quality of Multimedia Experience 2022
PDF data - Reviewing Best Practices in Online Conferencing
TechReport: arXiv:2212.11619 2022
PDF - Recommendations for Designing Hybrid Conferences
Journal: ACM SIGCOMM Computer Communication Review, Volume 52, Issue 2, April 2022
PDF - Interpreting Emoji with Emoji: 🏖️ => ☀️😎🌊
Conference: 5th International Workshop on Emoji Understanding and Applications in Social Media 2022
PDF video - Characterizing the country-wide adoption and evolution of the Jodel messaging app in Saudi Arabia
Journal: Webscience Journal 2022
PDF arXiv - Anonymous Hyperlocal Communities: What do they talk about?
Conference: WWW LocWeb Workshop 2022
PDF arXiv - Analysis of the LRU Cache StartUp Phase and Convergence Time and Error Bounds on Approximations by Fagin and Che
Conference: IEEE WiOpt 2022
PDF DOI - Lights on Power Plant Control Networks
Conference: Passive and Active Measurement Conference 2022
Abstract PDFAbstract: Industrial Control Systems (ICS) are critical systems to our society. Yet they are less studied given their closed nature and often the unavailability of data. While few studies focus on wide-area SCADA systems, e.g., power or gas distribution networks, mission critical networks that control power generation are not yet studied. To address this gap, we perform the first measurement study of Distributed Control System (DCS) by analyzing traces from all network levels from several operational power plants. We show that DCS networks feature a rather rich application mix compared to wide-area SCADA networks and that applications and sites can be fingerprinted with statistical means. While traces from operational power plants are hard to obtain, we analyze to which extent easier to access training facilities can be used as vantage points. Our study aims to shed light on traffic properties of critical industries that were not yet analyzed given the lack of data. - Differences in Social Media Interactions Exist Between Western and Middle-East Countries
Conference: Passive and Active Measurement Conference 2022
Abstract PDF arXiv videoAbstract: In this paper, we empirically analyze two examples of a Western (DE) versus Middle-East (SA) Online Social Messaging App. By focusing on the system interactions over time in comparison, we identify inherent differences in user engagement. We take a deep dive and shed light onto differences in user attention shifts and showcase their structural implications to the user experience. Our main findings show that in comparison to the German counterparts, the Saudi communities prefer creating content in longer conversations, while voting more conservative. - An Empirical View on Consolidation of the Web
Journal: ACM Transactions on Internet Technology (TOIT), Volume 22, August 2022
Abstract PDF videoAbstract: The majority of Web content is delivered by only a few companies that provide Content Delivery Infrastructuress (CDIss) such as Content Delivery Networkss (CDNss) and cloud hosts. Due to increasing concerns about trends of centralization, empirical studies on the extent and implications of resulting Internet consolidation are necessary. Thus, we present an empirical view on consolidation of the Web by leveraging datasets from two different measurement platforms. We first analyze Web consolidation around CDIs at the level of landing webpages, before narrowing down the analysis to a level of embedded page resources. The datasets cover 1(a) longitudinal measurements of DNS records for 166.5 M Web domains over five years, 1(b) measurements of DNS records for Alexa Top 1 M over a month and (2) measurements of page loads and renders for 4.3 M webpages, which include data on 392.3 M requested resources. We then define CDIs penetration as the ratio of CDI-hosted objects to all measured objects, which we use to quantify consolidation around CDIs. We observe that CDI penetration has close to doubled since 2015, reaching a lower bound of 15% for all .com, .net, and .org Web domains as of January 2020. Overall, we find a set of six CDIss to deliver the majority of content across all datasets, with these six CDIss being responsible for more than 80% of all 221.9 M CDI-delivered resources (56.6% of all resources in total). We find high dependencies of Web content on a small group of CDIss, in particular, for fonts, ads, and trackers, as well as JavaScript resources such as jQuery. We further observe CDIss to play important roles in rolling out IPv6 and TLS 1.3 support. Overall, these observations indicate a potential oligopoly, which brings both benefits but also risks to the future of the Web. - United We Stand: Collaborative Detection and Mitigation of Amplification DDoS Attacks at Scale
Conference: ACM Conference on Computer and Communications Security 2021
PDF DOI video 2022 IETF/IRTF Applied Networking Research Prize - CyberBunker 2.0 - A Domain and Traffic Perspective on a Bullet Proof Hoster
Conference: ACM Conference on Computer and Communications Security (Poster) 2021
PDF arXiv video - A Questionnaire to Assess Virtual Conference Participation Experience
Conference: IEEE Conference on Quality of Multimedia Experience 2021
PDF video - Blocklist Babel: On the Transparency and Dynamics of Open Source Blocklisting
Journal: IEEE Transactions on Network and Service Management, Volume 2021
PDF DOI - A Year in Lockdown: How the Waves of COVID-19 Impact Internet Traffic
Journal: Communications of the ACM, Volume 7, Issue 64 2021
PDF Research Highlight
[ Technical Perspective on our Article written by Jennifer Rexford (Princeton University) ] - Implications of the COVID-19 Pandemic on the Internet Traffic
Conference: ITG-Symposium on Broadband Coverage in Germany 2021
PDF
[ Invited paper ] - Understanding & Predicting User Lifetime with Machine Learning in an Anonymous Location-Based Social Network
Conference: WWW LocWeb Workshop 2021
PDF arXiv DOI slides - DDoS Never Dies? An IXP Perspective on DDoS Amplification Attacks
Conference: Passive and Active Measurement Conference 2021
arXiv video
[ Daniel’s talk at the RIPE 82 Anti Abuse WG meeting ] - The Boon and Bane of Cross-Signing: Shedding Light on a Common Practice in Public Key Infrastructures
Conference: ACM Conference on Computer and Communications Security 2020
Abstract arXiv DOIAbstract: Public Key Infrastructures (PKIs) with their trusted Certificate Authorities (CAs) provide the trust backbone for the Internet: CAs sign certificates which prove the identity of servers, applications, or users. To be trusted by operating systems and browsers, a CA has to undergo lengthy and costly validation processes. Alternatively, trusted CAs can cross-sign other CAs to extend their trust to them. In this paper, we systematically analyze the present and past state of cross-signing in the Web PKI. Our dataset (derived from passive TLS monitors and public CT logs) encompasses more than 7 years and 225 million certificates with 9.3 billion trust paths. We show benefits and risks of cross-signing. We discuss the difficulty of revoking trusted CA certificates where, worrisome, cross-signing can result in valid trust paths to remain after revocation; a problem for non-browser software that often blindly trusts all CA certificates and ignores revocations. However, cross-signing also enables fast bootstrapping of new CAs, e.g., Let’s Encrypt, and achieves a non-disruptive user experience by providing backward compatibility. In this paper, we propose new rules and guidance for cross-signing to preserve its positive potential while mitigating its risks. - The Lockdown Effect: Implications of the COVID-19 Pandemic on Internet Traffic
Conference: ACM Internet Measurement Conference 2020
Abstract PDF arXiv DOI videoAbstract: Due to the COVID-19 pandemic, many governments imposed lock-downs that forced hundreds of millions of citizens to stay at home. The implementation of confinement measures increased Internet traffic demands of residential users, in particular, for remote working, entertainment, commerce, and education, which, as a result, caused traffic shifts in the Internet core.In this paper, using data from a diverse set of vantage points (one ISP, three IXPs, and one metropolitan educational network), we examine the effect of these lockdowns on traffic shifts. We find that the traffic volume increased by 15-20% almost within a week—while overall still modest, this constitutes a large increase within this short time period. However, despite this surge, we observe that the Internet infrastructure is able to handle the new volume, as most traffic shifts occur outside of traditional peak hours. When looking directly at the traffic sources, it turns out that, while hypergiants still contribute a significant fraction of traffic, we see (1) a higher increase in traffic of non-hypergiants, and (2) traffic increases in applications that people use when at home, such as Web conferencing, VPN, and gaming. While many networks see increased traffic demands, in particular, those providing services to residential users, academic networks experience major overall decreases. Yet, in these networks, we can observe substantial increases when considering applications associated to remote working and lecturing. - Mis-shapes, Mistakes, Misfits: An Analysis of Domain Classification Services
Conference: ACM Internet Measurement Conference 2020
Abstract PDF DOI videoAbstract: Domain classification services have applications in multiple areas, including cybersecurity, content blocking, and targeted advertising. Yet, these services are often a black box in terms of their methodology to classifying domains, which makes it difficult to assess their strengths, aptness for specific applications, and limitations. In this work, we perform a large-scale analysis of 13 popular domain classification services on more than 4.4M hostnames. Our study empirically explores their methodologies, scalability limitations, label constellations, and their suitability to academic research as well as other practical applications such as content filtering. We find that the coverage varies enormously across providers, ranging from over 90% to below 1%. All services deviate from their documented taxonomy, hampering sound usage for research. Further, labels are highly inconsistent across providers, who show little agreement over domains, making it difficult to compare or combine these services. We also show how the dynamics of crowd-sourced efforts may be obstructed by scalability and coverage aspects as well as subjective disagreements among human labelers. Finally, through case studies, we showcase that most services are not fit for detecting specialized content for research or content-blocking purposes. We conclude with actionable recommendations on their usage based on our empirical insights and experience. Particularly, we focus on how users should handle the significant disparities observed across services both in technical solutions and in research. - Corona-Warn-App: Tracing the Start of the Official COVID-19 Exposure Notification App for Germany
Conference: ACM SIGCOMM Poster 2020
PDF arXiv DOI slides - Tracking the deployment of TLS 1.3 on the Web: A story of experimentation and centralization
Journal: ACM SIGCOMM Computer Communication Review, Volume 50, Issue 3, July 2020
PDF code data - Lessons Learned Organizing the PAM 2020 Virtual Conference
Journal: ACM SIGCOMM Computer Communication Review, Volume 50, Issue 3, July 2020
PDF data - Multi-episodic Perceived Quality of an Audio-on-Demand Service
Conference: IEEE Conference on Quality of Multimedia Experience 2020
PDF arXiv - Word-Emoji embeddings from large scale messaging data reflect real world semantic associations of expressive icons
Conference: ICWSM Workshop on Emoji Understanding and Applications in Social Media 2020
PDF arXiv - General Knapsack Bounds of Web Caching Performance Regarding the Properties of each Cacheable Object
Conference: Global Internet Symposium 2020
PDF - MUST, SHOULD, DON'T CARE: TCP conformance in the wild
Conference: Passive and Active Measurement Conference 2020
arXiv video code
[ Mike’s talk @ IRTF MAPRG Aug'20 ] - Congestion Control in the Wild - Investigating Content Provider Fairness
Journal: IEEE Transactions on Network and Service Management, Volume 17, Issue 2, June, pages 1224--1238 2020
PDF DOI - DDoS Hide & Seek: On the Effectiveness of a Booter Services Takedown
Conference: ACM Internet Measurement Conference 2019
PDF DOI slides video
[ Daniel’s Talk at LACNIC meeting ] - Hidden Treasures -- Recycling Large-Scale Internet Measurements to Study the Internet's Control Plane
Conference: Passive and Active Measurement Conference 2019
arXiv DOI slides - An Empirical View on Content Provider Fairness
Conference: Network Traffic Measurement and Analysis Conference 2019
PDF arXiv DOI - A Performance Perspective on Web Optimized Protocol Stacks: TCP+TLS+HTTP/2 vs. QUIC
Conference: ACM Applied Networking Research Workshop 2019
PDF arXiv DOI - Determining Response-generating Contexts on Microblogging Platforms
Conference: Conference on Natural Language Processing (KONVENS) 2019
PDF
[ Venue in linguistics ] - DeePCCI: Deep Learning-based Passive Congestion Control Identification
Conference: ACM SIGCOMM Workshop on Network Meets AI & ML 2019
PDF arXiv DOI - TheFragebogen: A Web Browser-based Questionnaire Framework for Scientific Research
Conference: IEEE Conference on Quality of Multimedia Experience 2019
PDF arXiv DOI code
[ Project page: thefragebogen.de ] - The Case for Session Sharing: Relieving Clients from TLS Handshake Overheads
Conference: IEEE LCN Symposium on Emerging Topics in Networking 2019
PDF DOI - Fast and Efficient Web Caching Methods Regarding the Size and Performance Measures per Data Object
Conference: IEEE International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD) 2019
DOI - Demystifying the Performance of Offloaded Packet Processing
Conference: IEEE Netsoft 2019
Abstract DOIAbstract: High packet rates at ≥ 10 GBit/s challenge the packet processing performance of network stacks. A common solution is to offload (parts of) the user-space packet processing to other execution environments, e.g., into the device driver (kernel-space), the NIC or even from virtual machines into the host operating system (OS), or any combination of those. While common wisdom states that offloading optimizes performance, neither benefits nor negative effects are comprehensively studied. In this paper, we aim to shed light on the benefits and shortcomings of eBPF/XDP-based offloading from the user-space to i) the kernel-space or ii) a smart NIC-including VM virtualization. We show that offloading can indeed optimize packet processing, but only if the task is small and optimized for the target environment. Otherwise, offloading can even lead to detrimental performance. - Hashtag Usage in a Geographically-Local Microblogging App
Conference: WWW LocWeb Workshop 2019
Abstract arXiv DOIAbstract: This paper studies for the first time the usage and propagation of hashtags in a new and fundamentally different type of social media that is i) without profiles and ii) location-based to only show nearby posted content. Our study is based on analyzing the mobile-only Jodel microblogging app, which has an established user base in several European countries and Saudi Arabia. All posts are user to user anonymous (i.e., no displayed user handles) and are only displayed in the proximity of the user’s location (up to 20 km). It thereby forms local communities and opens the question of how information propagates within and between these communities. We tackle this question by applying established metrics for Twitter hashtags to a ground-truth data set of Jodel posts within Germany that spans three years. We find the usage of hashtags in Jodel to differ from Twitter; despite embracing local communication in its design, Jodel hashtags are mostly used country-wide. - Hi Doppelgänger: Towards Detecting Manipulation in News Comments
Conference: WWW Cybersafety Workshop 2019
Abstract DOIAbstract:Public opinion manipulation is a serious threat to society, potentially influencing elections and the political situation even in established democracies. The prevalence of online media and the opportunity for users to express opinions in comments magnifies the problem. Governments, organizations, and companies can exploit this situation for biasing opinions. Typically, they deploy a large number of pseudonyms to create an impression of a crowd that supports specific opinions. Side channel information (such as IP addresses or identities of browsers) often allows a reliable detection of pseudonyms managed by a single person. However, while spoofing and anonymizing data that links these accounts is simple, a linking without is very challenging.
In this paper, we evaluate whether stylometric features allow a detection of such doppelgängers within comment sections on news articles. To this end, we adapt a state-of-the-art doppelgänger detector to work on small texts (such as comments) and apply it on three popular news sites in two languages. Our results reveal that detecting potential doppelgängers based on linguistics is a promising approach even when no reliable side channel information is available. Preliminary results following an application in the wild shows indications for doppelgängers in real world data sets.
- TCP's Initial Window –- Deployment in the Wild and its Impact on Performance
Journal: IEEE Transactions on Network and Service Management, Volume 16, Issue 2, June 2019
PDF DOI - Blitz-starting QUIC Connections
TechReport: arXiv:1905.03144 2019
PDF - Application-Agnostic Offloading of Packet Processing
TechReport: arXiv:1904.00671 2019
PDF - A Long Way to the Top: Significance, Structure, and Stability of Internet Top Lists
Conference: ACM Internet Measurement Conference 2018
arXiv DOI data ACM IMC Community Contribution Award
[ Press: netzpolitik.org ] - Digging into Browser-based Crypto Mining
Conference: ACM Internet Measurement Conference 2018
arXiv DOI
[ MIT Technology Review: This week’s most thought-provoking papers
Press: theregister.co.uk bitcoinist dailyhoodle.com ftreporter.com banklesstimes.com eyerys.com coincrispy.com playtech.ro webtekno.com digitaltrends.com bitcoin.com oracletimes.com thenextweb.com ] - Dissecting Apple's Meta-CDN during an iOS Update
Conference: ACM Internet Measurement Conference 2018
arXiv DOI - Operating a DNS-based Active Internet Observatory
Conference: ACM SIGCOMM Poster 2018
PDF - Demystifying TCP Initial Window Configurations of Content Distribution Networks
Conference: Network Traffic Measurement and Analysis Conference 2018
PDF - A First Look at Certification Authority Authorization (CAA)
Journal: ACM SIGCOMM Computer Communication Review, April 2018
PDF DOI data - A First Look at QUIC in the Wild
Conference: Passive and Active Measurement Conference 2018
arXiv DOI slides video data
[ Video of Jan’s talk at IETF-101 ] - Structure and Stability of Internet Top Lists
TechReport: PAM Poster arXiv:1802.02651 2018 - Application-Agnostic Offloading of Datagram Processing
Conference: International Teletraffic Congress 2018
PDF - Comparing Web Cache Implementations for Fast O(1) Updates Based on LRU, LFU and Score Gated Strategies
Conference: IEEE International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD) 2018 - Optimum Caching versus LRU/LFU Methods: Comparison and Combined Limited Look-Ahead Strategies
Conference: 3rd Content Caching and Delivery in Wireless Networks Workshop 2018
DOI - Scalability Issues and Solutions for Software Defined Networks (Editorial)
Journal: IEEE JSAC Special Issue on Scalability Issues and Solutions for Software Defined Networks, Volume 36, Issue 12, December 2018
DOI - Security and Performance of Software-defined Networks and Functions Virtualization
Journal: Elsevier Computer Networks, Volume 138, Issue 19, June, pages 15--17 2018
DOI - Giving Customers Control over Their Data: Integrating a Policy Language into the Cloud
Conference: IEEE International Conference on Cloud Engineering (IC2E) 2018
PDF DOI - A Quantitative Analysis of the Impact of Arbitrary Blockchain Content on Bitcoin
Conference: International Conference on Financial Cryptography and Data Security (FinancialCrypto) 2018
PDF - Large-Scale Scanning of TCP's Initial Window
Conference: ACM Internet Measurement Conference 2017
PDF - How HTTP/2 Pushes the Web: An Empirical Study of HTTP/2 Server Push
Conference: IFIP Networking Conference 2017
PDF - Veiled in Clouds? Assessing the Prevalence of Cloud Computing in the Email Landscape
Conference: Network Traffic Measurement and Analysis Conference 2017
PDF - Network Function Virtualization in Software Defined Infrastructures (Dagstuhl Seminar 17032)
Journal: Dagstuhl Reports, Volume 7, pages 74--102 2017
DOI - Performance Evaluation for New Web Caching Strategies Combining LRU with Score Based Object Selection
Journal: Elsevier Computer Networks, Volume 125, Issue 9, October, pages 172--186 2017
PDF - SymPerf: Predicting Network Function Performance
Conference: ACM SIGCOMM Poster 2017
DOI - Performance Evaluation for New Web Caching Strategies Combining LRU with Score Based Object Selection
Conference: International Teletraffic Congress 2016
DOI - STEAN: A Storage and Transformation Engine for Advanced Networking Context
Conference: IFIP NETWORKING 2016
PDF - ERWIN -- Enabling the Reproducible Investigation of Waiting Times for Arbitrary Workflows
Conference: IEEE Conference on Quality of Multimedia Experience 2016
PDF - Moving Privacy-Sensitive Services from Public Clouds to Decentralized Private Clouds
Conference: IEEE Workshop on Legal and Technical Issues in Cloud Computing and Cloud-Supported Internet of Things 2016
PDF - New Kid on the Block: Network Functions Virtualization: From Big Boxes to Carrier Clouds
Journal: ACM SIGCOMM Computer Communication Review, July 2016
PDF - Special issue on Software-Defined Networking and Network Functions Virtualization for flexible network management
Journal: Wiley International Journal of Network Management, Volume 26, Issue 1, pages 4--5 2016
DOI - Insensitivity to Network Delay: Minecraft Gaming Experience of Casual Gamers
Conference: IEEE QCMan 2016
PDF - It's time to combine Network Advances and Databases
Conference: ACM CoNEXT Student Workshop 2016 - POSTER: I Don't Want That Content! On the Risks of the Exploitability of Bitcoin's Blockchain as a Content Store
Conference: ACM CCS 2016
PDF - Annoyed Users: Ads and Ad-Block Usage in the Wild
Conference: ACM Internet Measurement Conference 2015
PDF - On the Applicability of Computer Vision based Gaze Tracking in Mobile Scenarios
Conference: ACM MobileHCI 2015
PDF code - Santa: Faster Packet Delivery for Commonly Wished Replies [Poster Abstract]
Conference: ACM SIGCOMM Poster 2015
PDF DOI - Distributed Cloud Computing: Applications, Status Quo, and Challenges
Journal: ACM SIGCOMM Computer Communication Review, Volume 44, April 2015
PDF DOI - Subjective Quality of Webpage Loading: The Impact of Delayed and Missing Elements
Conference: IEEE Conference on Quality of Multimedia Experience 2015
PDF - A QoE Perspective on Sizing Network Buffers
Conference: ACM Internet Measurement Conference 2014
PDF - On Capacity Dimensioning in Dynamic Scenarios: The Key Role of Peak Values
Conference: IEEE LANMAN 2014
PDF - An Internet census taken by an illegal botnet - A qualitative assessment of published measurements
Journal: ACM SIGCOMM Computer Communication Review, Volume 44, July 2014
PDF - The Harvester, the Botmaster, and the Spammer: On the Relations Between the Different Actors in the Spam Landscape
Conference: ACM Symposium on Information, Computer and Communications Security 2014 - Impact of Buffering on User Experience
PhD Thesis TU Berlin 2013
PDF - Longtime Behavior of Harvesting Spam Bots
Conference: ACM Internet Measurement Conference 2012
PDF - BufferBloat: How Relevant? A QoE Perspective on Buffer Sizing
TechReport: TU Berlin, Fak. IV 2012
PDF - On the Convergence to Fairness in Overloaded FIFO Systems
Conference: IEEE INFOCOM 2011
PDF - On Revealing the ARQ Mechanism of MSTV
Conference: IEEE ICC 2011
PDF - Analysis of Random and Burst Error Codes in 2-state Markov Channels
Conference: 34th International Conference on Telecommunications and Signal Processing 2011
PDF DOI - Impact of Frame Rate and Resolution on Objective QoE Metrics
Conference: IEEE Conference on Quality of Multimedia Experience 2010
PDF DOI - The Routerlab --- Emulating Internet Characteristics in a Room
Conference: 11th ITG conference on photonic networks 2010
PDF - Efficiency of Caches for Content Distribution in the Internet
Conference: International Teletraffic Congress 2010
PDF DOI - Non-Asymptotic Throughput and Delay Distributions in Multi-Hop Wireless Networks
Conference: 48th Annual Allerton Conference on Communication, Control, and Computing 2010
PDF DOI - Towards QoE Management for Scalable Video Streaming
Conference: 21st ITC Specialist Seminar on Multimedia Applications - Traffic, Performance and QoE 2010
PDF - On Computing Bounds on Average Backlogs and Delays with Network Calculus
Conference: IEEE ICC 2010
PDF DOI - Scaling of Buffer and Capacity Requirements of Voice Traffic in Packet Networks
Conference: International Teletraffic Congress 2009
PDF - Viewing Impaired Video Transmissions From a Modeling Perspective
Journal: Performance Evaluation Review, Volume 37, September, pages 33--35 2009
PDF DOI
[ Workshop on MAthematical Performance Modeling and Analysis (MAMA) at Sigmetrics ] - Stochastic Packet Loss Model to Evaluate QoE Impairments
Journal: PIK, pages 53--56 2009
PDF - Stochastic Packet Loss Model to Evaluate QoE Impairments
Conference: KiVS: Master Thesis Award Session 2009
PDF - Packet Loss in Real-Time Services: Markovian Models Generating QoE Impairments
Conference: IEEE International Workshop on Quality of Service (IWQoS) 2008
PDF DOI - The Gilbert-Elliott Model for Packet Loss in Real Time Services
on the Internet
Conference: GI/ITG Conference on Measurement, Modeling, and Evaluation of Computer and Communication Systems (MMB) 2008
Abstract PDF
[ Errata ]Abstract: The estimation of quality for real-time services over telecommunication networks requires realistic models for impairments and failures during transmission. We focus on the classical Gilbert-Elliott model whose second order statistics is derived over arbitrary time scales and used to fit packet loss processes of traffic traces measured in the IP backbone of Deutsche Telekom. The results show that simple Markov models are appropriate to capture the observed loss pattern. - Instant Messaging Communication Gateway for Medical Applications
Conference: Proceedings of the IASTED International Conference on Telehealth 2005
AbstractAbstract: Internet has changed the way of how people communicate and exchange information. Enduringly, more and more doctors are getting familiar with Internet and the offered capabilities. Hospitals are interconnected, making use of Internet, forming medical information networks. The doctors exchange information with the help of Internet. A very common way of communication is the electronic email even when a doctor looks for a second opinion from another expert doctor. In the market, various medical applications for tele-consultation can be found. Some of them are web based and others are stand alone applications. In this paper we will propose a communication gateway, based on Jabber instant messaging protocol, for modern and demanding medical applications, focusing on tele consultation applications. The proposed gateway is able to handle connections restricted by firewalls and makes use of potential available proxies inside of a network. In addition, we will address the problems related to firewalls and proxies and will proposed a new way of communication for medical applications based on Jabber an instant messaging protocol. Furthermore, in order to handle binary data transmission to an offline entity over a Jabber network, we proposed an extension to In-Band Byte streams communication protocol. - Implementation of a Jabber-Based Medical Tele-Consulting Application
Conference: 5th International Network Conference (INC) 2005
2024
SIGCOMM'24
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2023
TNSM'23
COMNET'23
arXiv'23
WFCS'23
2022
SIGCOMM'22
QoMEX'22
arXiv'22
CCR'22
Emoji'22
Webscience Journal'22
WWW LocWeb'22
WiOpt'22
PAM'22
PAM'22
TOIT'22
2021
CCS'21
CCS-Poster'21
CoNEXT Student'21
QoMEX'21
TNSM'21
CACM'21
ITG'21
WWW LocWeb'21
PAM'21
2020
CCS'20
IMC'20
IMC'20
SIGCOMM Poster'20
CCR'20
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QoMEX'20
ICWSM Emoji'20
GI'20
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TNSM'20
2019
IMC'19
PAM'19
TMA'19
CoNEXT'19
ANRW'19
KONVENS'19
SIGCOMM NetAI'19
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LCN'19
CAMAD'19
Netsoft'19
WWW LocWeb'19
WWW Cybersafety'19
TNSM'19
arXiv'19
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2018
IMC'18
IMC'18
IMC'18
SIGCOMM Poster'18
TMA'18
CCR'18
PAM'18
PAM'18
PAM Poster'18
ITC'18
CAMAD'18
'18
JSAC'18
Comnet'18
IC2E'18
FinancalCrypto'18
2017
IMC'17
Internet-QoE'17
NETWORKING'17
TMA'17
Dagstuhl'17
Comnet'17
'17
2016
ITC'16
NETWORKING'16
QoMEX'16
'16
CCR'16
'16
QCMan'16
'16
CCS Poster'16
2015
IMC'15
MobileHCI'15
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2014
IMC'14
LANMAN'14
CCR'14
AsiaCCS'14
2013
PhD Thesis'13
2012
IMC'12
TechRep'12
2011
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ICC'11
TSP'11
2010
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'10
ITC'10
Allerton'10
ITC-SS'10
ICC'10
2009
ITC'09
SIGMETRICS MAMA'09
'09
KiVS'09
2008
IWQoS'08
MMB'08
2005
'05
'05
Theses
PhD Thesis (2013)
Impact of Buffering on Quality of Experience
Technische Universität Berlin, 2013
Advisor: Anja Feldmann Dissertation Committee:
- Sebastian Möller (Chair)
- Anja Feldmann (TU Berlin)
- Paul Barford (University of Wisconsin - Madison, USA)
- Alexander Raake (TU Berlin)
PDF Abstract / TU Berlin Metadata
Master Thesis (2008)
Statistical Error Model to Impair an H.264 Decoder
Technische Universität Darmstadt, 2008
I received the KuVS Master Thesis Award for the best master thesis in this area at the KiVS conference 2009. I also received a Master Thesis Award at MMB 2010.
Bachelor Thesis (2006)
Development of a instant messaging-based communication module for telemedical applications
University of Applied Sciences Darmstadt
Hohlfeld, Oliver: Development of an Instant Messaging-based Communication Module for Telemedical Applications. In: Computer Graphic Topics, 17 (4), 2005, p. 43
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Address:
Oliver Hohlfeld
University of Kassel
Distributed Systems Group
Wilhelmshöher Allee 73
34121 Kassel, Germany MapEmail: oliver dot hohlfeld at uni-kassel /DOT/ de
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Netray Internet Observatory
- netray.IO
- QUIC Adoption
- HTTP2 Adoption
- TCP Initial Window Configurations
- Certificate Authority Authorization (CAA)