MCQUIC: Multicast and unicast in a single transport protocol

Multicast enables efficient one-to-many communications. Several applications benefit from its scalability properties, e.g., live-streaming and large-scale software updates. Historically, multicast applications have used specialized transport protocols. The flexibility of the recently standardized QUIC protocol opens the possibility of providing both unicast and multicast services to applications with a single transport protocol. We present MCQUIC, an extended version of the QUIC protocol that supports multicast communications. We show how QUIC features and built-in security can be leveraged for multicast transport. We present the design of MCQUIC and implement it in Cloudflare quiche. We assess its performance through benchmarks and in emulated networks under realistic scenarios. We also demonstrate MCQUIC in a campus network. By coupling QUIC with our multicast extension, applications can rely on multicast for efficiency with the possibility to fall back on unicast in case of incompatible network conditions.Comment: 13 page

Revealing the Evolution of a Cloud Provider Through its Network Weather Map

peer reviewedResearchers often face the lack of data on large operational networks to understand how they are used, how they behave, and sometimes how they fail. This data is crucial to drive the evolution of Internet protocols and develop techniques such as traffic engineering, DDoS detection and mitigation. Companies that have access to measurements from operational networks and services leverage this data to improve the availability, speed, and resilience of their Internet services. Unfortunately, the availability of large datasets, especially collected regularly over a long period of time, is a daunting task that remains scarce in the literature. We tackle this problem by releasing a dataset collected over roughly two years of observations of a major cloud company (OVH). Our dataset, called OVH Weather dataset, represents the evolution of more than 180 routers, 1,100 internal links, 500 external links, and their load percentages in the backbone network over time. Our dataset has a high density with snapshots taken every five minutes, totaling more than 500,000 files. In this paper, we also illustrate how our dataset could be used to study the backbone networks evolution. Finally, our dataset opens several exciting research questions that we make available to the research community

Etude par spectroscopie Mössbauer de l'altération des minéralisations sulfurées

Thèse de doctorat en sciences -- UCL, 197

International engineering project management: key success factors in a changing industry

Le texte intégral de ce document de travail n'est pas disponible en ligne. Une copie papier est disponible à l'Annexe de la bibliothéque. Effectuez une recherche par titre dans le catalogue pour réserver le document. // The full text of this working paper is not available online. A print copy is available in the Library Annex. Search by title in the catalogue to request the paper

It Is Time to Reconsider Multicast

Multicast enables efficient point-to-multi-points communications. However, due to several deployment issues, multicast research slowed in the early 2000s and many of its use-cases were replaced by Content Delivery Networks and unicast communications. We argue that despite its past deployment complexities, multicast should be reconsidered to build a more energy-efficient Internet. We highlight using measurements in emulated networks the benefits of multicast regarding CPU cycles and traffic volume. Moreover, we discuss how the past limitations could be solved with today's Internet architecture and protocols, such as the Bit Index Explicit Replication mechanism

SRv6-FEC: Bringing Forward Erasure Correction to IPv6 Segment Routing

IPv6 Segment Routing (SRv6) is a recent implementation of the source routing paradigm in IPv6 network. A programmability framework has recently been added to SRv6 and enables it to support diverse use-cases. We leverage this support to design, implement, and assess a Forward Erasure Correction (FEC) technique that transparently protects IPv6 packets. We implement our encoders and decoders using eBPF on the Linux kernel and evaluate the benefits that they bring with IoT devices

Experimenting with Bit Index Explicit Replication

Bit Index Explicit Replication (BIER) is a recent multicast architecture that solves several problems with deployed IP multicast protocols. BIER embeds an implicit multicast tree representation inside each transmitted packet. With this new mechanism, it becomes possible to reconsider multicast applications. However, no open-source implementation of BIER can be found. This paper presents our open-source implementation of the BIER forwarding mechanism and a companion socket-like API. Additionally, we show simulations of the implementation with ns-3 DCE

Design of project management systems from top management's perspective

Le texte intégral de ce document de travail n'est pas disponible en ligne. Une copie papier est disponible à l'Annexe de la bibliothéque. Effectuez une recherche par titre dans le catalogue pour réserver le document. // The full text of this working paper is not available online. A print copy is available in the Library Annex. Search by title in the catalogue to request the paper

Leveraging eBPF to Make TCP Path-Aware

The Transmission Control Protocol (TCP) is one of the key Internet protocols. It is used by a broad range of applications. TCP was designed when there was typically a single path between a client and a server. Today’s networks provide higher path diversity, yet TCP still only uses the single path selected by the network layer. This limits the ability of TCP to react to events such as interdomain failures or highly congested peering links. We propose the TCP Path Changer (TPC), a set of eBPF programs that are incorporated into the Linux TCP/IP stack to make it more agile. To illustrate the benefits of our approach, we first demonstrate that TPC can quickly reroute an ongoing TCP connection around a failure. We then show that TPC can also monitor the round-trip-time of active TCP connections and automatically reroute them if it becomes too high. Our evaluation of TPC in emulated networks evidences the significant performance benefits of a path-aware transport protocol