TY - RPRT A1 - Vomhoff, Viktoria A1 - Geissler, Stefan A1 - Gebert, Steffen A1 - Hossfeld, Tobias T1 - Towards Understanding the Global IPX Network from an MVNO Perspective T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - In this paper, we work to understand the global IPX network from the perspective of an MVNO. In order to do this, we provide a brief description of the global architecture of mobile carriers. We provide initial results with respect to mapping the vast and complex interconnection network enabling global roaming from the point of view of a single MVNO. Finally, we provide preliminary results regarding the quality of service observed under global roaming conditions. KW - global IPX network Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322121 ER - TY - RPRT A1 - Navade, Piyush A1 - Maile, Lisa A1 - German, Reinhard T1 - Multiple DCLC Routing Algorithms for Ultra-Reliable and Time-Sensitive Applications T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - This paper discusses the problem of finding multiple shortest disjoint paths in modern communication networks, which is essential for ultra-reliable and time-sensitive applications. Dijkstra’s algorithm has been a popular solution for the shortest path problem, but repetitive use of it to find multiple paths is not scalable. The Multiple Disjoint Path Algorithm (MDPAlg), published in 2021, proposes the use of a single full graph to construct multiple disjoint paths. This paper proposes modifications to the algorithm to include a delay constraint, which is important in time-sensitive applications. Different delay constraint least-cost routing algorithms are compared in a comprehensive manner to evaluate the benefits of the adapted MDPAlg algorithm. Fault tolerance, and thereby reliability, is ensured by generating multiple link-disjoint paths from source to destination. KW - Dijkstra’s algorithm KW - shortest path routing KW - disjoint multi-paths KW - delay constrained KW - least cost Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322177 ER - TY - RPRT A1 - Deutschmann, Jörg A1 - Hielscher, Kai-Steffen A1 - German, Reinhard T1 - Next-Generation Satellite Communication Networks T2 - Würzburg Workshop on Next-Generation Communication Networks (WueWoWas'22) N2 - This paper gives an overview of our recent activities in the field of satellite communication networks, including an introduction to geostationary satellite systems and Low Earth Orbit megaconstellations. To mitigate the high latencies of geostationary satellite networks, TCP-splitting Performance Enhancing Proxies are deployed. However, these cannot be applied in the case of encrypted transport headers as it is the case for VPNs or QUIC. We summarize performance evaluation results from multiple measurement campaigns. In a recently concluded project, multipath communication was used to combine the advantages of very heterogeneous communication paths: low data rate, low latency (e.g., DSL light) and high data rate, high latency (e.g., geostationary satellite). KW - Datennetz KW - satellite communication KW - Performance Enhancing Proxies KW - transport protocols KW - VPN KW - QUIC KW - multipath communication KW - hybrid access Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-280732 ER - TY - RPRT A1 - Riegler, Clemens A1 - Werner, Lennart A1 - Kayal, Hakan T1 - MAPLE: Marsian Autorotation Probe Lander Experiment N2 - The first step towards aerial planetary exploration has been made. Ingenuity shows extremely promising results, and new missions are already underway. Rotorcraft are capable of flight. This capability could be utilized to support the last stages of Entry, Descent, and Landing. Thus, mass and complexity could be scaled down. Autorotation is one method of descent. It describes unpowered descent and landing, typically performed by helicopters in case of an engine failure. MAPLE is suggested to test these procedures and understand autorotation on other planets. In this series of experiments, the Ingenuity helicopter is utilized. Ingenuity would autorotate a ”mid-air-landing” before continuing with normal flight. Ultimately, the collected data shall help to understand autorotation on Mars and its utilization for interplanetary exploration. T3 - Raumfahrttechnik und Extraterrestrik - 2 KW - autorotation KW - descent KW - Mars KW - rotorcraft KW - landing KW - aerospace Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-282390 ER - TY - RPRT A1 - Simon, Manuel A1 - Gallenmüller, Sebastian A1 - Carle, Georg T1 - Never Miss Twice - Add-On-Miss Table Updates in Software Data Planes T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - State Management at line rate is crucial for critical applications in next-generation networks. P4 is a language used in software-defined networking to program the data plane. The data plane can profit in many circumstances when it is allowed to manage its state without any detour over a controller. This work is based on a previous study by investigating the potential and performance of add-on-miss insertions of state by the data plane. The state keeping capabilities of P4 are limited regarding the amount of data and the update frequency. We follow the tentative specification of an upcoming portable-NIC-architecture and implement these changes into the software P4 target T4P4S. We show that insertions are possible with only a slight overhead compared to lookups and evaluate the influence of the rate of insertions on their latency. KW - SDN KW - state management KW - P4 KW - Add-on-Miss Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322071 ER - TY - RPRT A1 - Brisch, Fabian A1 - Kassler, Andreas A1 - Vestin, Jonathan A1 - Pieska, Marcus A1 - Amend, Markus T1 - Accelerating Transport Layer Multipath Packet Scheduling for 5G-ATSSS T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - Utilizing multiple access networks such as 5G, 4G, and Wi-Fi simultaneously can lead to increased robustness, resiliency, and capacity for mobile users. However, transparently implementing packet distribution over multiple paths within the core of the network faces multiple challenges including scalability to a large number of customers, low latency, and high-capacity packet processing requirements. In this paper, we offload congestion-aware multipath packet scheduling to a smartNIC. However, such hardware acceleration faces multiple challenges due to programming language and platform limitations. We implement different multipath schedulers in P4 with different complexity in order to cope with dynamically changing path capacities. Using testbed measurements, we show that our CMon scheduler, which monitors path congestion in the data plane and dynamically adjusts scheduling weights for the different paths based on path state information, can process more than 3.5 Mpps packets 25 μs latency. KW - multipath packet scheduling KW - P4 KW - MP-DCCP KW - 5G KW - ATSSSS Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322052 ER - TY - RPRT A1 - Hasslinger, Gerhard A1 - Ntougias, Konstantinos A1 - Hasslinger, Frank A1 - Hohlfeld, Oliver T1 - Performance Analysis of Basic Web Caching Strategies (LFU, LRU, FIFO, ...) with Time-To-Live Data Validation T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - Web caches often use a Time-to-live (TTL) limit to validate data consistency with web servers. We study the impact of TTL constraints on the hit ratio of basic strategies in caches of fixed size. We derive analytical results and confirm their accuracy in comparison to simulations. We propose a score-based caching method with awareness of the current TTL per data for improving the hit ratio close to the upper bound. KW - LRU KW - LFU KW - FIFO caching strategies KW - hit ratio analysis and simulation KW - TTL validation of data consistency Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322048 ER - TY - RPRT A1 - Funda, Christoph A1 - Marín García, Pablo A1 - German, Reinhard A1 - Hielscher, Kai-Steffen T1 - Online Algorithm for Arrival & Service Curve Estimation T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - This paper presents a novel concept to extend state-of-the-art buffer monitoring with additional measures to estimate service-curves. The online algorithm for service-curve estimation replaces the state-of-the-art timestamp logging, as we expect it to overcome the main disadvantages of generating a huge amount of data and using a lot of CPU resources to store the data to a file during operation. We prove the accuracy of the online-algorithm offline with timestamp data and compare the derived bounds to the measured delay and backlog. We also do a proof-of- concept of the online-algorithm, implement it in LabVIEW and compare its performance to the timestamp logging by CPU load and data-size of the log-file. However, the implementation is still work-in-progress. KW - hardware-in-the-loop streaming system KW - network calculus KW - service-curve estimation KW - performance monitoring Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322112 ER - TY - RPRT A1 - Mazigh, Sadok Mehdi A1 - Beausencourt, Marcel A1 - Bode, Max Julius A1 - Scheffler, Thomas T1 - Using P4-INT on Tofino for Measuring Device Performance Characteristics in a Network Lab T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - This paper presents a prototypical implementation of the In-band Network Telemetry (INT) specification in P4 and demonstrates a use case, where a Tofino Switch is used to measure device and network performance in a lab setting. This work is based on research activities in the area of P4 data plane programming conducted at the network lab of HTW Berlin. KW - P4-INT Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322084 ER - TY - RPRT A1 - Nguyen, Kien A1 - Loh, Frank A1 - Hoßfeld, Tobias T1 - Challenges of Serverless Deployment in Edge-MEC-Cloud T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - The emerging serverless computing may meet Edge Cloud in a beneficial manner as the two offer flexibility and dynamicity in optimizing finite hardware resources. However, the lack of proper study of a joint platform leaves a gap in literature about consumption and performance of such integration. To this end, this paper identifies the key questions and proposes a methodology to answer them. KW - Edge-MEC-Cloud Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322025 ER - TY - RPRT A1 - Raffeck, Simon A1 - Geißler, Stefan A1 - Hoßfeld, Tobias T1 - Towards Understanding the Signaling Traffic in 5G Core Networks T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - The Fifth Generation (5G) communication technology, its infrastructure and architecture, though already deployed in campus and small scale networks, is still undergoing continuous changes and research. Especially, in the light of future large scale deployments and industrial use cases, a detailed analysis of the performance and utilization with regard to latency and service times constraints is crucial. To this end, a fine granular investigation of the Network Function (NF) based core system and the duration for all the tasks performed by these services is necessary. This work presents the first steps towards analyzing the signaling traffic in 5G core networks, and introduces a tool to automatically extract sequence diagrams and service times for NF tasks from traffic traces. KW - signaling traffic KW - 5G core network Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322106 ER - TY - RPRT A1 - Großmann, Marcel A1 - Homeyer, Tobias T1 - Emulation of Multipath Transmissions in P4 Networks with Kathará T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - Packets sent over a network can either get lost or reach their destination. Protocols like TCP try to solve this problem by resending the lost packets. However, retransmissions consume a lot of time and are cumbersome for the transmission of critical data. Multipath solutions are quite common to address this reliability issue and are available on almost every layer of the ISO/OSI model. We propose a solution based on a P4 network to duplicate packets in order to send them to their destination via multiple routes. The last network hop ensures that only a single copy of the traffic is further forwarded to its destination by adopting a concept similar to Bloom filters. Besides, if fast delivery is requested we provide a P4 prototype, which randomly forwards the packets over different transmission paths. For reproducibility, we implement our approach in a container-based network emulation system called Kathará. KW - P4 KW - multipath KW - emulation KW - Kathará Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322095 ER - TY - RPRT A1 - Riegler, Clemens A1 - Kayal, Hakan T1 - VELEX: Venus Lightning Experiment N2 - Lightning has fascinated humanity since the beginning of our existence. Different types of lightning like sprites and blue jets were discovered, and many more are theorized. However, it is very likely that these phenomena are not exclusive to our home planet. Venus’s dense and active atmosphere is a place where lightning is to be expected. Missions like Venera, Pioneer, and Galileo have carried instruments to measure electromagnetic activity. These measurements have indeed delivered results. However, these results are not clear. They could be explained by other effects like cosmic rays, plasma noise, or spacecraft noise. Furthermore, these lightning seem different from those we know from our home planet. In order to tackle these issues, a different approach to measurement is proposed. When multiple devices in different spacecraft or locations can measure the same atmospheric discharge, most other explanations become increasingly less likely. Thus, the suggested instrument and method of VELEX incorporates multiple spacecraft. With this approach, the question about the existence of lightning on Venus could be settled. T3 - Raumfahrttechnik und Extraterrestrik - 3 KW - Venus KW - Lightning KW - CubeSat KW - Balloon KW - Autorotation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-282481 ER - TY - RPRT A1 - Grigorjew, Alexej A1 - Schumann, Lukas Kilian A1 - Diederich, Philip A1 - Hoßfeld, Tobias A1 - Kellerer, Wolfgang T1 - Understanding the Performance of Different Packet Reception and Timestamping Methods in Linux T2 - KuVS Fachgespräch - Würzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS’23) N2 - This document briefly presents some renowned packet reception techniques for network packets in Linux systems. Further, it compares their performance when measuring packet timestamps with respect to throughput and accuracy. Both software and hardware timestamps are compared, and various parameters are examined, including frame size, link speed, network interface card, and CPU load. The results indicate that hardware timestamping offers significantly better accuracy with no downsides, and that packet reception techniques that avoid system calls offer superior measurement throughput. KW - packet reception method KW - timestamping method KW - Linux Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-322064 ER - TY - RPRT A1 - Elsayed, Karim A1 - Rizk, Amr T1 - Response Times in Time-to-Live Caching Hierarchies under Random Network Delays T2 - Würzburg Workshop on Next-Generation Communication Networks (WueWoWas'22) N2 - Time-to-Live (TTL) caches decouple the occupancy of objects in cache through object-specific validity timers. Stateof- the art techniques provide exact methods for the calculation of object-specific hit probabilities given entire cache hierarchies with random inter-cache network delays. The system hit probability is a provider-centric metric as it relates to the origin offload, i.e., the decrease in the number of requests that are served by the content origin server. In this paper we consider a user-centric metric, i.e., the response time, which is shown to be structurally different from the system hit probability. Equipped with the state-of-theart exact modeling technique using Markov-arrival processes we derive expressions for the expected object response time and pave a way for its optimization under network delays. KW - Datennetz KW - TTL Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-280843 ER - TY - RPRT A1 - Alfredsson, Rebecka A1 - Kassler, Andreas A1 - Vestin, Jonathan A1 - Pieska, Marcus A1 - Amend, Markus T1 - Accelerating a Transport Layer based 5G Multi-Access Proxy on SmartNIC T2 - Würzburg Workshop on Next-Generation Communication Networks (WueWoWas'22) N2 - Utilizing multiple access technologies such as 5G, 4G, and Wi-Fi within a coherent framework is currently standardized by 3GPP within 5G ATSSS. Indeed, distributing packets over multiple networks can lead to increased robustness, resiliency and capacity. A key part of such a framework is the multi-access proxy, which transparently distributes packets over multiple paths. As the proxy needs to serve thousands of customers, scalability and performance are crucial for operator deployments. In this paper, we leverage recent advancements in data plane programming, implement a multi-access proxy based on the MP-DCCP tunneling approach in P4 and hardware accelerate it by deploying the pipeline on a smartNIC. This is challenging due to the complex scheduling and congestion control operations involved. We present our pipeline and data structures design for congestion control and packet scheduling state management. Initial measurements in our testbed show that packet latency is in the range of 25 μs demonstrating the feasibility of our approach. KW - Datennetz KW - multipath KW - MP-DCCP KW - 5G-ATSSS KW - networking KW - dataplane programming KW - P4 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-280798 ER - TY - RPRT ED - Hoßfeld, Tobias ED - Wunderer, Stefan T1 - White Paper on Crowdsourced Network and QoE Measurements – Definitions, Use Cases and Challenges N2 - The goal of the white paper at hand is as follows. The definitions of the terms build a framework for discussions around the hype topic ‘crowdsourcing’. This serves as a basis for differentiation and a consistent view from different perspectives on crowdsourced network measurements, with the goal to provide a commonly accepted definition in the community. The focus is on the context of mobile and fixed network operators, but also on measurements of different layers (network, application, user layer). In addition, the white paper shows the value of crowdsourcing for selected use cases, e.g., to improve QoE or regulatory issues. Finally, the major challenges and issues for researchers and practitioners are highlighted. This white paper is the outcome of the Würzburg seminar on “Crowdsourced Network and QoE Measurements” which took place from 25-26 September 2019 in Würzburg, Germany. International experts were invited from industry and academia. They are well known in their communities, having different backgrounds in crowdsourcing, mobile networks, network measurements, network performance, Quality of Service (QoS), and Quality of Experience (QoE). The discussions in the seminar focused on how crowdsourcing will support vendors, operators, and regulators to determine the Quality of Experience in new 5G networks that enable various new applications and network architectures. As a result of the discussions, the need for a white paper manifested, with the goal of providing a scientific discussion of the terms “crowdsourced network measurements” and “crowdsourced QoE measurements”, describing relevant use cases for such crowdsourced data, and its underlying challenges. During the seminar, those main topics were identified, intensively discussed in break-out groups, and brought back into the plenum several times. The outcome of the seminar is this white paper at hand which is – to our knowledge – the first one covering the topic of crowdsourced network and QoE measurements. KW - Crowdsourcing KW - Network Measurements KW - Quality of Service (QoS) KW - Quality of Experience (QoE) KW - crowdsourced network measurements KW - crowdsourced QoE measurements Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202327 ER - TY - RPRT A1 - Metzger, Florian T1 - Crowdsensed QoE for the community - a concept to make QoE assessment accessible N2 - In recent years several community testbeds as well as participatory sensing platforms have successfully established themselves to provide open data to everyone interested. Each of them with a specific goal in mind, ranging from collecting radio coverage data up to environmental and radiation data. Such data can be used by the community in their decision making, whether to subscribe to a specific mobile phone service that provides good coverage in an area or in finding a sunny and warm region for the summer holidays. However, the existing platforms are usually limiting themselves to directly measurable network QoS. If such a crowdsourced data set provides more in-depth derived measures, this would enable an even better decision making. A community-driven crowdsensing platform that derives spatial application-layer user experience from resource-friendly bandwidth estimates would be such a case, video streaming services come to mind as a prime example. In this paper we present a concept for such a system based on an initial prototype that eases the collection of data necessary to determine mobile-specific QoE at large scale. In addition we reason why the simple quality metric proposed here can hold its own. KW - Quality of Experience KW - Crowdsourcing KW - Crowdsensing KW - QoE Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203748 N1 - Originally written in 2017, but never published. ER - TY - RPRT A1 - Lhamo, Osel A1 - Nguyen, Giang T. A1 - Fitzek, Frank H. P. T1 - Virtual Queues for QoS Compliance of Haptic Data Streams in Teleoperation T2 - Würzburg Workshop on Next-Generation Communication Networks (WueWoWas'22) N2 - Tactile Internet aims at allowing perceived real-time interactions between humans and machines. This requires satisfying a stringent latency requirement of haptic data streams whose data rates vary drastically as the results of perceptual codecs. This introduces a complex problem for the underlying network infrastructure to fulfill the pre-defined level of Quality of Service (QoS). However, novel networking hardware with data plane programming capability allows processing packets differently and opens up a new opportunity. For example, a dynamic and network-aware resource management strategy can help satisfy the QoS requirements of different priority flows without wasting precious bandwidth. This paper introduces virtual queues for service differentiation between different types of traffic streams, leveraging protocol independent switch architecture (PISA). We propose coordinating the management of all the queues and dynamically adapting their sizes to minimize packet loss and delay due to network congestion and ensure QoS compliance. KW - Datennetz KW - data plane programming KW - software defined network KW - P4 KW - virtual queue KW - haptic data Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-280762 ER - TY - RPRT A1 - Vomhoff, Viktoria A1 - Geißler, Stefan A1 - Hoßfeld, Tobias T1 - Identification of Signaling Patterns in Mobile IoT Signaling Traffic T2 - Würzburg Workshop on Next-Generation Communication Networks (WueWoWas'22) N2 - We attempt to identify sequences of signaling dialogs, to strengthen our understanding of the signaling behavior of IoT devices by examining a dataset containing over 270.000 distinct IoT devices whose signaling traffic has been observed over a 31-day period in a 2G network [4]. We propose a set of rules that allows the assembly of signaling dialogs into so-called sessions in order to identify common patterns and lay the foundation for future research in the areas of traffic modeling and anomaly detection. KW - Datennetz KW - IoT Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-280819 ER -