Publications
2018 |
Desmouceaux, Yoann; Cordero, Juan Antonio; Clausen, Thomas Reliable B.I.E.R. with Peer Caching Journal Article Forthcoming Forthcoming. @article{Desmouceaux2018c, title = {Reliable B.I.E.R. with Peer Caching}, author = {Yoann Desmouceaux and Juan Antonio Cordero and Thomas Clausen}, year = {2018}, date = {2018-06-01}, abstract = {Multicast protocols usually require building multicast trees and maintaining state in intermediate routers, incurring operation complexity. B.I.E.R. (Bit-Indexed Explicit Replication) ambitions to alleviate this complexity by allowing for source-driven selection of destinations and state-less packet forwarding. B.I.E.R. can also be used to achieve reliable delivery of content, by retransmitting packet to the exact set of destinations which have missed it. While B.I.E.R.- based reliable multicast exhibits attractive performance attributes, repair of a lost packet is achieved through source retransmissions, which may be costly and even unnecessary if close peers are able to provide a copy of the packet. Thus, this paper extends the use of reliable B.I.E.R. multicast to allow recoveries from peers, using Segment Routing (SR) to steer retransmission requests through potential candidates. A framework is introduced, which can accommodate different policies for the selection of candidate peers for retransmissions. Simple (both static and adaptive) policies are introduced and analyzed, both (i) theoretically and (ii) by way of simulations in data-center-like and real-world topologies. Results indicate that local peer recovery is able to substantially reduce the overall retransmission traffic, and that this can be achieved through simple policies, where no signaling is required to build a set of candidate peers.}, keywords = {}, pubstate = {forthcoming}, tppubtype = {article} } Multicast protocols usually require building multicast trees and maintaining state in intermediate routers, incurring operation complexity. B.I.E.R. (Bit-Indexed Explicit Replication) ambitions to alleviate this complexity by allowing for source-driven selection of destinations and state-less packet forwarding. B.I.E.R. can also be used to achieve reliable delivery of content, by retransmitting packet to the exact set of destinations which have missed it. While B.I.E.R.- based reliable multicast exhibits attractive performance attributes, repair of a lost packet is achieved through source retransmissions, which may be costly and even unnecessary if close peers are able to provide a copy of the packet. Thus, this paper extends the use of reliable B.I.E.R. multicast to allow recoveries from peers, using Segment Routing (SR) to steer retransmission requests through potential candidates. A framework is introduced, which can accommodate different policies for the selection of candidate peers for retransmissions. Simple (both static and adaptive) policies are introduced and analyzed, both (i) theoretically and (ii) by way of simulations in data-center-like and real-world topologies. Results indicate that local peer recovery is able to substantially reduce the overall retransmission traffic, and that this can be achieved through simple policies, where no signaling is required to build a set of candidate peers. |
Desmouceaux, Yoann; Toubaline, Sonia; Clausen, Thomas Flow-Aware Workload Migration in Data Centers Journal Article Springer - Journal of Network and Systems Management (JONS), 2018. @article{Desmouceaux2018a, title = {Flow-Aware Workload Migration in Data Centers}, author = {Yoann Desmouceaux and Sonia Toubaline and Thomas Clausen}, url = {https://link.springer.com/epdf/10.1007/s10922-018-9452-5?author_access_token=qm_40d91CsNLlZ_vZ0tZFPe4RwlQNchNByi7wbcMAY4xSrvbLplDMLQ3AN9vWEoUIxtZAIdnOGAzJH5W3YOrbGteOLvaEXsEE1xFv66lVxTKlL40BAS25fsaLf8w1RJAvY69owHWqhJkTmAZpvdCkQ%3D%3D https://www.epizeuxis.net/wp-content/uploads/2018/03/jons-2018.pdf}, doi = {10.1007/s10922-018-9452-5}, year = {2018}, date = {2018-03-10}, journal = {Springer - Journal of Network and Systems Management (JONS)}, abstract = {In data centers, subject to workloads with heterogeneous (and sometimes short) lifetimes, workload migration is a way of attaining a more efficient utilization of the underlying physical machines. To not introduce performance degradation, such workload migration must take into account not only machine resources, and per-task resource requirements, but also application dependencies in terms of network communication. This articleformat presents a workload migration model capturing all of these constraints. A linear programming framework is developed allowing accurate representation of per-task resources requirements and inter-task network demands. Using this, a multi-objective problem is formulated to compute a re-allocation of tasks that (i) maximizes the total inter-task throughput, while (ii) minimizing the cost incurred by migration and (iii) allocating the maximum number of new tasks. A baseline algorithm, solving this multi-objective problem using the $epsilon$-constraint method is proposed, in order to generate the set of Pareto-optimal solutions. As this algorithm is compute-intensive for large topologies, a heuristic, which computes an approximation of the Pareto front, is then developed, and evaluated on different topologies and with different machine load factors. These evaluations show that the heuristic can provide close-to-optimal solutions, while reducing the solving time by one to two order of magnitudes. }, keywords = {}, pubstate = {published}, tppubtype = {article} } In data centers, subject to workloads with heterogeneous (and sometimes short) lifetimes, workload migration is a way of attaining a more efficient utilization of the underlying physical machines. To not introduce performance degradation, such workload migration must take into account not only machine resources, and per-task resource requirements, but also application dependencies in terms of network communication. This articleformat presents a workload migration model capturing all of these constraints. A linear programming framework is developed allowing accurate representation of per-task resources requirements and inter-task network demands. Using this, a multi-objective problem is formulated to compute a re-allocation of tasks that (i) maximizes the total inter-task throughput, while (ii) minimizing the cost incurred by migration and (iii) allocating the maximum number of new tasks. A baseline algorithm, solving this multi-objective problem using the $epsilon$-constraint method is proposed, in order to generate the set of Pareto-optimal solutions. As this algorithm is compute-intensive for large topologies, a heuristic, which computes an approximation of the Pareto front, is then developed, and evaluated on different topologies and with different machine load factors. These evaluations show that the heuristic can provide close-to-optimal solutions, while reducing the solving time by one to two order of magnitudes. |
Desmouceaux, Yoann; Clausen, Thomas; Cordero, Juan Antonio; Townsley, Mark W Reliable Multicast with B.I.E.R. Journal Article Forthcoming IEEE/KICS Journal of Communications and Networks (JCN), 20 (2), pp. 182-197, Forthcoming. @article{Desmouceaux0000, title = {Reliable Multicast with B.I.E.R.}, author = {Yoann Desmouceaux and Thomas Clausen and Juan Antonio Cordero and W. Mark Townsley }, url = {http://www.thomasclausen.net/wp-content/uploads/2018/03/jcn-2018.pdf}, year = {2018}, date = {2018-02-28}, journal = {IEEE/KICS Journal of Communications and Networks (JCN)}, volume = {20}, number = {2}, pages = {182-197}, abstract = {Inter-network multicast protocols, which build and maintain multicast trees, incur both explicit protocol signalling, and maintenance of state in intermediate routers in the network. B.I.E.R. (Bit-Indexed Explicit Replication) is a technique which can provide a multicast service yet removes such complexities: in- termediate routers are unencumbered by group management, and no per-group state is to be maintained. This paper explores the use of B.I.E.R. as a basis for develop- ing an efficient and reliable multicast mechanism, where redun- dant traffic is avoided, essential traffic is forwarded along shortest paths, and no per-flow state is required in intermediate routers. Evaluated by way of both an analytical model and network sim- ulation both in generic and in real network topologies with vary- ing background traffic loads, the proposed B.I.E.R.-based reliable multicast mechanism exhibits attractive performance attributes: it attains delivery success rates as high as any other reliable multicast service, but with significantly better link utilisation and no per-flow or per-group state in intermediate routers of the network.}, keywords = {}, pubstate = {forthcoming}, tppubtype = {article} } Inter-network multicast protocols, which build and maintain multicast trees, incur both explicit protocol signalling, and maintenance of state in intermediate routers in the network. B.I.E.R. (Bit-Indexed Explicit Replication) is a technique which can provide a multicast service yet removes such complexities: in- termediate routers are unencumbered by group management, and no per-group state is to be maintained. This paper explores the use of B.I.E.R. as a basis for develop- ing an efficient and reliable multicast mechanism, where redun- dant traffic is avoided, essential traffic is forwarded along shortest paths, and no per-flow state is required in intermediate routers. Evaluated by way of both an analytical model and network sim- ulation both in generic and in real network topologies with vary- ing background traffic loads, the proposed B.I.E.R.-based reliable multicast mechanism exhibits attractive performance attributes: it attains delivery success rates as high as any other reliable multicast service, but with significantly better link utilisation and no per-flow or per-group state in intermediate routers of the network. |
Desmouceaux, Yoann; Pfister, Pierre; Tollet, Jérôme; Townsley, Mark W; Clausen, Thomas 6LB: Scalable and Application-Aware Load Balancing with Segment Routing Journal Article IEEE/ACM Transactions on Networking, 26 (2), pp. 819-834, 2018, ISSN: 1063-6692. @article{Desmouceaux2018, title = {6LB: Scalable and Application-Aware Load Balancing with Segment Routing}, author = {Yoann Desmouceaux and Pierre Pfister and Jérôme Tollet and W. Mark Townsley and Thomas Clausen}, url = {http://www.thomasclausen.net/wp-content/uploads/2018/02/2018-IEEE-Transactions-on-Networking-6LB-Scalable-and-Application-Aware-Load-Balancing-with-Segment-Routing.pdf}, doi = {10.1109/TNET.2018.2799242}, issn = {1063-6692}, year = {2018}, date = {2018-02-15}, journal = {IEEE/ACM Transactions on Networking}, volume = {26}, number = {2}, pages = {819-834}, abstract = {Network load-balancers generally either do not take application state into account, or do so at the cost of a central- ized monitoring system. This paper introduces a load-balancer running exclusively within the IP forwarding plane, i.e. in an application protocol agnostic fashion – yet which still provides application-awareness and makes real-time, decentralized deci- sions. To that end, IPv6 Segment Routing is used to direct data packets from a new flow through a chain of candidate servers, until one decides to accept the connection, based solely on its local state. This way, applications themselves naturally decide on how to fairly share incoming connections, while incurring minimal network overhead, and no out-of-band signaling. A consistent hashing algorithm, as well as an in-band stickiness protocol, allow for the proposed solution to be able to be reliably distributed across a large number of instances. Performance evaluation by means of an analytical model and actual tests on different workloads (including a Wikipedia replay as a realistic workload) show significant performance benefits in terms of shorter response times, when compared to a traditional random load-balancer. In addition, this paper introduces and compares kernel bypass high-performance implementations of both 6LB and a state-of-the-art load-balancer, showing that the significant system-level benefits of 6LB are achievable with a negligible data-path CPU overhead.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Network load-balancers generally either do not take application state into account, or do so at the cost of a central- ized monitoring system. This paper introduces a load-balancer running exclusively within the IP forwarding plane, i.e. in an application protocol agnostic fashion – yet which still provides application-awareness and makes real-time, decentralized deci- sions. To that end, IPv6 Segment Routing is used to direct data packets from a new flow through a chain of candidate servers, until one decides to accept the connection, based solely on its local state. This way, applications themselves naturally decide on how to fairly share incoming connections, while incurring minimal network overhead, and no out-of-band signaling. A consistent hashing algorithm, as well as an in-band stickiness protocol, allow for the proposed solution to be able to be reliably distributed across a large number of instances. Performance evaluation by means of an analytical model and actual tests on different workloads (including a Wikipedia replay as a realistic workload) show significant performance benefits in terms of shorter response times, when compared to a traditional random load-balancer. In addition, this paper introduces and compares kernel bypass high-performance implementations of both 6LB and a state-of-the-art load-balancer, showing that the significant system-level benefits of 6LB are achievable with a negligible data-path CPU overhead. |
2017 |
Perez, Samuel; Cordero, Juan Antonio; Coupechoux, Marceau ODMAC++: An IoT Communication Manager based on Energy Harvesting Prediction Inproceedings Proceedings of the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'2017)., IEEE, 2017. @inproceedings{Perez2017, title = {ODMAC++: An IoT Communication Manager based on Energy Harvesting Prediction}, author = {Samuel Perez and Juan Antonio Cordero and Marceau Coupechoux}, year = {2017}, date = {2017-10-08}, booktitle = {Proceedings of the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'2017).}, publisher = {IEEE}, abstract = {In large low-power networks of battery-driven sen- sors, power outages are a major concern and communication rates have to be carefully designed in order to optimize energy consumption, network connectivity and sensors lifetime. In some IoT use cases, power can be supplied to sensors by way of renewable energy automatic harvesting (solar panels, etc.). Given the high variability of energy arrival processes, energy consumption in sensors, in particular caused by transmissions to the sink, has to be aligned with energy harvesting patterns, so as to maximize throughput while avoiding power outages that may arise when the battery is empty. This paper proposes ODMAC++, an extension to a well-known protocol for sensor transmission scheduling in a WSN. ODMAC++ relies on learning techniques to adapt sensors communication rate to energy harvesting patterns, and uses a beaconing mechanism whose frequency is adjusted based on past measurements on the harvested energy process. Simulations based on analytical energy arrival models and on real solar radiation measurements indicate that ODMAC++ is able to avoid power outages and to cope with battery limitation and energy variations due to variability in time.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } In large low-power networks of battery-driven sen- sors, power outages are a major concern and communication rates have to be carefully designed in order to optimize energy consumption, network connectivity and sensors lifetime. In some IoT use cases, power can be supplied to sensors by way of renewable energy automatic harvesting (solar panels, etc.). Given the high variability of energy arrival processes, energy consumption in sensors, in particular caused by transmissions to the sink, has to be aligned with energy harvesting patterns, so as to maximize throughput while avoiding power outages that may arise when the battery is empty. This paper proposes ODMAC++, an extension to a well-known protocol for sensor transmission scheduling in a WSN. ODMAC++ relies on learning techniques to adapt sensors communication rate to energy harvesting patterns, and uses a beaconing mechanism whose frequency is adjusted based on past measurements on the harvested energy process. Simulations based on analytical energy arrival models and on real solar radiation measurements indicate that ODMAC++ is able to avoid power outages and to cope with battery limitation and energy variations due to variability in time. |
Desmouceaux, Yoann; Pfister, Pierre; Tollet, Jerome; Townsley, Mark W; Clausen, Thomas SRLB: The Power of Choices in Load Balancing with Segment Routing Inproceedings In Proceedings of the 37th IEEE International Conference on Distributed Computing Systems (ICDCS), 2017. @inproceedings{Desmouceaux2017b, title = {SRLB: The Power of Choices in Load Balancing with Segment Routing}, author = {Yoann Desmouceaux and Pierre Pfister and Jerome Tollet and W. Mark Townsley and Thomas Clausen}, url = {http://www.thomasclausen.net/wp-content/uploads/2017/05/camera-ready-ieeepdfexpress.pdf}, year = {2017}, date = {2017-06-05}, booktitle = {In Proceedings of the 37th IEEE International Conference on Distributed Computing Systems (ICDCS)}, abstract = {Network load-balancers generally either do not take application state into account, or do so at the cost of a central- ized monitoring system. This paper introduces a load-balancer running exclusively within the IP forwarding plane, i.e. in an application protocol agnostic fashion – yet which still provides application-awareness and makes real-time, decentralized deci- sions. To that end, IPv6 Segment Routing is used to direct data packets from a new flow through a chain of candidate servers, until one decides to accept the connection, based on its local state. This way, applications themselves naturally decide on how to share incoming connections, while incurring minimal network overhead, and no out-of-band signaling. Tests on different workloads – including realistic workloads such as replaying actual Wikipedia access traffic towards a set of replica Wikipedia instances – show significant performance benefits, in terms of shorter response times, when compared to a traditional random load-balancer.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Network load-balancers generally either do not take application state into account, or do so at the cost of a central- ized monitoring system. This paper introduces a load-balancer running exclusively within the IP forwarding plane, i.e. in an application protocol agnostic fashion – yet which still provides application-awareness and makes real-time, decentralized deci- sions. To that end, IPv6 Segment Routing is used to direct data packets from a new flow through a chain of candidate servers, until one decides to accept the connection, based on its local state. This way, applications themselves naturally decide on how to share incoming connections, while incurring minimal network overhead, and no out-of-band signaling. Tests on different workloads – including realistic workloads such as replaying actual Wikipedia access traffic towards a set of replica Wikipedia instances – show significant performance benefits, in terms of shorter response times, when compared to a traditional random load-balancer. |
2016 |
Augustin, Aloys; Yi, Jiazi; Clausen, Thomas; Townsley, Mark A Study of LoRa: Long Range & Low Power Networks for the Internet of Things Journal Article MDPI Sensors, 16 (9), pp. 1466, 2016, ISSN: 1424-8220, ((5 yr Impact Factor: 2.437)). @article{Augustin2016, title = {A Study of LoRa: Long Range & Low Power Networks for the Internet of Things}, author = {Aloys Augustin and Jiazi Yi and Thomas Clausen and Mark Townsley}, url = {http://www.thomasclausen.net/2016-a-study-of-lora-long-range-low-power-networks-for-the-internet-of-things/}, doi = {10.3390/s16091466}, issn = {1424-8220}, year = {2016}, date = {2016-09-09}, journal = {MDPI Sensors}, volume = {16}, number = {9}, pages = {1466}, abstract = {LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed.}, note = {(5 yr Impact Factor: 2.437)}, keywords = {}, pubstate = {published}, tppubtype = {article} } LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed. |
Jin, Kaiwan; Pfister, Pierre; Yi, Jiazi Distributed Node Consensus Protocol: Analysis, Evaluation and Performance Inproceedings Proceedings of the IEEE International Conference on Communications (ICC) 2016, 2016. @inproceedings{Jin2016, title = {Distributed Node Consensus Protocol: Analysis, Evaluation and Performance}, author = {Kaiwan Jin and Pierre Pfister and Jiazi Yi}, doi = {10.1109/ICC. 2016.7510939}, year = {2016}, date = {2016-05-23}, publisher = {Proceedings of the IEEE International Conference on Communications (ICC) 2016}, abstract = {Abstract—This paper analyzes and evaluates the Distributed Node Consensus Protocol (DNCP), a state synchronization mech- anism developed by the IETF Homenet working group. DNCP enables network function automation for home networks, which are growing in size and complexity. The basic mechanisms of DNCP are studied in this paper, including the state abstraction, synchronization process and keep-alive mechanism. The over- head is analyzed in single-link topology type. To evaluate the performance of DNCP in more complex scenarios, a reference implementation of DNCP is integrated into ns3 simulator. The convergence time and transmission overhead in various topology types are measured. Based on the obtained results, the correctness of DNCP is verified, and the behavior of DNCP can be concluded.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Abstract—This paper analyzes and evaluates the Distributed Node Consensus Protocol (DNCP), a state synchronization mech- anism developed by the IETF Homenet working group. DNCP enables network function automation for home networks, which are growing in size and complexity. The basic mechanisms of DNCP are studied in this paper, including the state abstraction, synchronization process and keep-alive mechanism. The over- head is analyzed in single-link topology type. To evaluate the performance of DNCP in more complex scenarios, a reference implementation of DNCP is integrated into ns3 simulator. The convergence time and transmission overhead in various topology types are measured. Based on the obtained results, the correctness of DNCP is verified, and the behavior of DNCP can be concluded. |
