Pierre François

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We describe and analyse in details the various factors that influence the convergence time of intradomain link state routing protocols. This convergence time reflects the time required by a network to react to the failure of a link or a router. To characterise the convergence process, we first use detailed measurements to determine the time required to(More)
A few modifications to software and/or hardware of routers have been proposed recently to avoid the transient micro loops that can occur during the convergence of link-state interior gateway protocols like IS-IS and OSPF. We1 propose in this paper a technique that does not require modifications to ISIS and OSPF, and that can be applied now by ISPs. Roughly,(More)
When using link-state protocols such as OSPF or IS-IS, forwarding loops can occur transiently when the routers adapt their forwarding tables as a response to a topological change. In this paper, we present a mechanism that lets the network converge to its optimal forwarding state without risking any transient loops and the related packet loss. The mechanism(More)
We first show by measurements that BGP peering links fail as frequently as intradomain links and usually for short periods of time. We propose a new fast-reroute technique where routers are <i>prepared</i> to react quickly to interdomain link failures. For each of its interdomain links, each router precomputes a <i>protection tunnel</i>, i.e. an IP tunnel(More)
In grapevine, as in other fruit crops, fruit size and seed content are key components of yield and quality; however, very few Quantitative Trait Loci (QTLs) for berry weight and seed content (number, weight, and dry matter percentage) have been discovered so far. To identify new stable QTLs for marker-assisted selection and candidate gene identification, we(More)
Network researchers often need to evaluate newly proposed algorithms and protocols over realistic topologies. Many researchers use random networks for such evaluations. Unfortunately, random networks do not accurately model real networks and important parameters such as link metrics or iBGP configurations are often ignored. We propose IGen, a freely(More)
SDN simplifies network management by relying on declarativity (high-level interface) and expressiveness (network flexibility). We propose a solution to support those features while preserving high robustness and scalability as needed in carrier-grade networks. Our solution is based on (i) a two-layer architecture separating connectivity and optimization(More)
When the topology of an IP network changes due to a link failure or a link metric modification, the routing tables of all the routers must be updated. Each of those updates may cause transient loops. In this paper, we prove that by ordering the updates of the routing tables on the routers, it is possible to avoid all transient loops during the convergence(More)
Network operators anticipate the offering of an increasing variety of cloud-based services with stringent Service Level Agreements. Technologies currently supporting IP networks however lack the flexibility and scalability properties to realize such evolution. In this article, we present Segment Routing (SR), a new network architecture aimed at filling this(More)