Čičić, Tarik; Kvalbein, Amund; Al-Selwi, Anas Saeed; Michelinakis, Foivos Ioannis and Dreibholz, Thomas: ``Norske mobilnett i 2022 – Tilstandsrapport fra Centre for Resilient Networks and Applications´´ (PDF, 8343 KiB, 44 pages, på norsk), Simula Metropolitan Center for Digital Engineering, Centre for Resilient Networks and Applications (CRNA), ISBN 978-82-92593-38-7, Oslo/Norway, April 27, 2023.
Abstract: Denne rapporten er utarbeidet av Center for Resilient Networks and Applications (CRNA), som er en del av Simula Metropolitan Center for Digital Engineering. CRNA driver grunnleggende forskning innen robusthet og sikkerhet i nettverk med mandat og finansiering fra Kommunal- og moderniseringsdepartementet. Senteret produserer en årlig rapport om tilstanden i norske mobilnett. Årets rapport er den tiende i rekken
URL: https://web-backend.simula.no/sites/default/files/publications/files/crna-2022.pdf
MD5: 0e3fb8dba3abb5a4877bf234cbb64a4a
Mazumdar, Somnath and Dreibholz, Thomas: ``Secure Embedded Living: Towards a Self-contained User Data Preserving Framework´´ (PDF, 336 KiB, 7 pages, in English), in IEEE Communications Magazine, vol. 60, pp. 74–80, DOI 10.1109/MCOM.001.2200165, ISSN 0163-6804, November 11, 2022.
Keywords: IoTs, Cloud, Blockchain, Data, Security, User
Abstract: Smart living represents the hardware-software co-inhabiting with humans for better living standards and improved well-being. Here, hardware monitors human activities (by collecting data) specific to a context. Such data can be processed to offer context-specific valuable insights. Such insights can be used for optimising the well-being, living experience and energy cost of smart homes. This paper proposes a Secure Embedded Living Framework (SELF) that enforces a privacy-preserving data control mechanism by integrating multiple technologies, such as Internet-of-thing, cloud/fog platform, machine learning and blockchain. The primary aim of the SELF is to allow the user to retain more control of its data.
URL: https://web-backend.simula.no/sites/default/files/publications/files/commmag2022.pdf
MD5: aee5a6a9043799f00b9836ce7cafd8d4
Adhari, Hakim; Werner, Sebastian; Dreibholz, Thomas and Rathgeb, Erwin Paul: ``LEDBAT-MP – On the Application of Lower-than-Best-Effort for Concurrent Multipath Transfer´´ (PDF, 1229 KiB, 7 pages, in English), in Proceedings of the 4th International Workshop on Protocols and Applications with Multi-Homing Support (PAMS), DOI 10.1109/WAINA.2014.125, ISBN 978-1-4799-2652-7, Victoria, British Columbia/Canada, May 16, 2014.
Keywords: Multi-Path Transfer, Congestion Control, Background Traffic, CMT-SCTP, MPTCP
Abstract: The Internet is based on best effort communication, i.e. it tries to deliver packets but does not provide any guarantees. A transport protocol can make use of this best effort service to provide a suitable service to its applications. Also, its congestion control is responsible for a fair distribution of the resources within the Internet. However, background data transfer applications (like file sharing or update fetching) do not require "best effort", they in fact could use a "lower-than-best-effort" service to leave resources to more important applications if needed. For this purpose, the Low Extra Delay Background Transport (LEDBAT) algorithm has been standardized by the IETF.
Nowadays, multi-homing is becoming increasingly common in modern networks and several approaches to exploit this feature (e.g. CMT-SCTP, MPTCP) have evolved that are able to combine resources of multiple paths. For background traffic oriented algorithms like LEDBAT, this feature could be of great use, too, i.e. by increasing the overall bandwidth while shifting the transmission away from paths which are used by other flows. This could be particularly useful for non-critical bulk transfers in data centres. In this paper, we introduce our approach LEDBAT for Multi-Path – denoted as LEDBAT-MP – and analyze its performance by simulations. With this paper, we want to highlight some generic design questions and start a discussion on how a solid universal background multi-path congestion control strategy should behave.
URL: https://web-backend.simula.no/sites/default/files/publications/Simula.simula.2512.pdf
MD5: dfdfcfef3b476f3d9aad8215ef058662
Dreibholz, Thomas: ``NorNet – An Open, Large-Scale Testbed for Multi-Homed Systems´´ (PDF, 4655 KiB, 31 pages, in English), Invited Talk at Swinburne University, Centre for Advanced Internet Architectures (CAIA), Melbourne, Victoria/Australia, January 30, 2014.
Keywords: NorNet, NorNet Core, NorNet Edge, Testbed, Multi-Homing, Introduction, Status
Abstract: Multi-homing denotes the simultaneous connection of endpoints (e.g. cloud servers, smartphones, etc.) to multiple Internet Service Providers (ISP). That is, the endpoints remain reachable even when some of the ISPs have problems (e.g. malfunction of hardware or break of cables). Besides the redundancy aspect, multi-homing can also make load sharing by multi-path transport possible, i.e. increasing the application throughput by utilising multiple paths simultaneously. Multi-path transport can e.g. be realised by Concurrent Multi-Path Transfer for SCTP (CMT-SCTP) and Multi-Path TCP (MPTCP), two protocols that are currently under standardisation in the IETF.
The growing need for and deployment of multi-homed applications makes large-scale testing and evaluation in realistic Internet setups necessary. For instance, different paths can have very different characteristics with regard to bandwidth, packet loss rate, congestion, delay and jitter. Therefore, the NorNet project of the Simula Research Laboratory is building up an open platform for such experiments: the NorNet testbed. It provides programmable nodes with multiple ISP connections – wired as well as wireless – that are distributed all over Norway as well as some international locations. This talk will give an overview over NorNet with a focus on its usage for research on multi-path transport. Particularly, it will also show how the NorNet testbed can be utilised for research at CAIA/Swinburne University.
URL: https://web-backend.simula.no/sites/default/files/publications/files/caia2014-presentation-web.pdf
MD5: 2c2282e72cc039210aa3b8ee97b389a6
Dreibholz, Thomas and Gran, Ernst Gunnar: ``Design and Implementation of the NorNet Core Research Testbed for Multi-Homed Systems´´ (PDF, 20082 KiB, 7 pages, in English), in Proceedings of the 3nd International Workshop on Protocols and Applications with Multi-Homing Support (PAMS), pp. 1094–1100, DOI 10.1109/WAINA.2013.71, ISBN 978-0-7695-4952-1, Barcelona, Catalonia/Spain, March 27, 2013.
Keywords: NorNet, Testbed, Multi-Homing, Design, Implementation
Abstract: The Internet has made it possible to communicate and to use services over large geographical distances. While it has originally been built for less critical services like e-mail and file transfer, it is nowadays also increasingly often used for availability-critical services like e.g. e-commerce or healthcare. Clearly, the reachability of such services must be ensured by so-called multi-homing of endpoints. That is, endpoints are simultaneously connected to multiple Internet Service Providers (ISP) to provide redundancy. If one ISP has problems, it is intended that the connection to another one still works. However, such assumptions have never been verified in real, large-scale setups.
The intention of the NorNet project is to build up a realistic Internet testbed for multi-homing. In this paper, we describe the design of NorNet with focus on the implementation of its fixed-line part: NorNet Core. This paper is intended to give researchers an overview of its mode of operation, its capabilities as well as its interesting feature realisations. The knowledge about these items is very useful to plan own experiments in the NorNet testbed.
MD5: 6560234f120c9c1e0166928b1c13e400
Dreibholz, Thomas: ``Evaluation and Optimisation of Multi-Path Transport using the Stream Control Transmission Protocol´´ (PDF, 36779 KiB, 264 pages, in English), Habilitation Treatise, University of Duisburg-Essen, Faculty of Economics, Institute for Computer Science and Business Information Systems, URN urn:nbn:de:hbz:464-20120315-103208-1, March 13, 2012.
Keywords: Stream Control Transmission Protocol (SCTP), Multi-Path Transport, Dissimilar Paths, Fairness, Evaluation, Optimisation
Abstract: The Stream Control Transmission Protocol (SCTP) as defined in RFC 4960 is an advanced Transport Layer protocol that provides support for multi-homing. That is, SCTP endpoints may simultaneously use multiple Network Layer addresses, which allows to connect the endpoints to multiple networks for redundancy purposes. However, for the transfer of user data, only one of the possible paths is currently used at a time. All other paths remain as backup and are only used for retransmissions.
Clearly, the existence of multiple paths has led to the idea of applying load sharing among the paths. An extension to SCTP – denoted as Concurrent Multipath Transfer (CMT) – realises this load sharing functionality. While this approach works well for similar paths, i.e. paths having similar characteristics regarding bandwidths, bit error rates and delays, the use of dissimilar paths does not work that neatly.
In this thesis, the issues of dissimilar paths for CMT-based load sharing will be demonstrated first. The reasons for these issues will be identified and solutions proposed. These solutions will be evaluated in simulations, as well as partially also in a real-world Internet testbed setup, in order to show their effectiveness. In particular, it will be shown that a combination of multiple mechanisms is necessary to make CMT work as expected under a wide range of network and system parameters.
Furthermore, the fairness of CMT-based transport – in concurrency to classic non-CMT flows – will be analysed. The usage of plain CMT leads to an overly aggressive bandwidth occupation on so-called shared bottlenecks. As a countermeasure, the idea of Resource Pooling will be utilised. For this purpose, two new and one adapted congestion control approach – all based on the Resource Pooling principle – will be introduced and examined in similar as well as dissimilar path setups, in order to show how to fairly deploy CMT transport in the Internet.
The results of this work have also been contributed to the ongoing IETF standardisation process of SCTP and its extensions.
MD5: add34f0b780cb35b7ee1f963ea85e59c
Dreibholz, Thomas; Becke, Martin; Rathgeb, Erwin Paul and Tüxen, Michael: ``On the Use of Concurrent Multipath Transfer over Asymmetric Paths´´ (PDF, 1036 KiB, 6 pages, in English), in Proceedings of the IEEE Global Communications Conference (GLOBECOM), DOI 10.1109/GLOCOM.2010.5683579, ISBN 978-1-4244-5637-6, Miami, Florida/U.S.A., December 7, 2010.
Keywords: Concurrent Multipath Transfer, Resource Pooling, Asymmetric Paths, Buffer Handling, Performance Analysis
Abstract: With the deployment of more and more resilience-critical Internet applications, there is a rising demand for multi-homed network sites. This leads to the desire for simultaneously utilising all available access paths to improve application data throughput. This is commonly known as Concurrent Multipath Transfer (CMT), approaches for several Transport Layer protocols have been proposed. Combined with Resource Pooling (RP), CMT can also fairly coexist with concurrent non-CMT flows. Current approaches focus on symmetric paths (i.e. similar bandwidth, delay and error rate). However, asymmetric paths are much more likely – particularly for realistic Internet setups – and efficient CMT usage on such paths is therefore crucial.
In this paper, we first show the challenges of plain as well as RP-aware CMT data transport over asymmetric paths. After that, we introduce mechanisms for efficient transport over such paths. Finally, we analyse the performance of our approaches by using simulations.
URL: https://www.wiwi.uni-due.de/fileadmin/fileupload/I-TDR/SCTP/Paper/Globecom2010.pdf
MD5: 96629a6c95f6882e9fdd54acdee2de5d
Dreibholz, Thomas; IJsselmuiden, Avril J. and Adams, John L.: ``An Advanced QoS Protocol for Mass Content´´ (PDF, 113 KiB, 2 pages, in English), in Proceedings of the IEEE Conference on Local Computer Networks (LCN) 30th Anniversary, pp. 517–518, DOI 10.1109/LCN.2005.25, ISBN 0-7695-2421-4, Sydney, New South Wales/Australia, November 17, 2005.
Keywords: Quality of Service (QoS), Signalling Protocols, Telecommunication Congestion Control, Telecommunication Traffic
Abstract: This paper presents a novel network device being located in network edge nodes. It provides a solution for QoS guarantees to certain flows on a congested link by focussing packet discard on selected flows. Unlike IntServ solutions like RSVP, our approach only requires minimal signalling and provides both efficiency and scalability.
In this paper, we first describe the ideas of our QoS device and then provide first results from a fast-track simulation model implementing a lightweight version of our approach.
URL: https://www.wiwi.uni-due.de/fileadmin/fileupload/I-TDR/FlowRouting/Paper/LCN2005-EdgeDevice.pdf
MD5: 081882106105904aa7f496def9022c4e
Dreibholz, Thomas: ``Das rsplib–Projekt – Hochverfügbarkeit mit Reliable Server Pooling´´ (PDF, 1154 KiB, 19 pages, auf Deutsch), in Proceedings of the LinuxTag, Karlsruhe, Baden-Württemberg/Germany, June 24, 2005.
Keywords: Reliable Server Pooling (RSerPool)
Abstract: In unserem Paper geben wir zunächst eine Einführung zu Reliable Server Pooling (RSerPool), danach stellen wir unsere Implementation vor – das rsplib-Projekt. Im Anschluß daran zeigen wir, wie basierend auf unserer Implementation eigene, hochverfügbare Anwendungen mit RSerPool entwickelt werden können – begleitet durch Code-Beispiele. Zum Abschluß stellen wir noch eine unserer Beispielanwendungen vor.
URL: https://www.wiwi.uni-due.de/fileadmin/fileupload/I-TDR/ReliableServer/Publications/LinuxTag2005.pdf
MD5: 7e2afb7bb1cc82c458c4ac8217d3f8d0