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Routing Protocols
Project leader : O. Bonaventure
Researchers : P. François, B. Quoitin, V. Vanden Schrieck, L. Vanbever, P. Mérindol Research team: INL (IP Networking Lab)
Collaborations :
Funds : Cisco Systems, France Telecom, Trilogy project Publication : here Description : Research activities in the department deals with the improvement of routing protocols (http://inl.info.ucl.ac.be/projects/improving-convergence-routing-protocols):
A first project aims to measure, analyse, and improve the convergence (adaptation to a topological change) of the intradomain routing protocols that are used inside today's Autonomous Systems (AS). We focus on the link-state protocols (OSPF, IS-IS) that are widely used. Firstly, we developed a simulator to quantify the factors that influence the convergence time after a topological change inside a network, given its topology (routers, links, link delays), hardware characteristics (cpu time to perform the required operations, OS specific properties) and router configurations (link metrics, artificial delaying of the topological change information). The interest of such simulations is that it is very hard to reproduce realistic experiments in a lab, as the studied topologies can contain several hundreds of routers and links, while covering all the possible topological changes scenario. The simulator helped us to verify that transient forwarding inconsistencies in the routers can occur during the convergence phase, leading to forwarding loops and packet drops. By analysing the reason for those loops, we found that it is possible to force the routers to be consistent, for all the destinations, during the whole convergence. This can be achieved by slightly changing the currently deployed protocols. The ideas and proofs that underlie this consistent rerouting scheme have been published. We would like to extend our protocol modification to treat the case of networks using multiple IGP areas and support the concurrent failures of multiple links. We also plan to extend our solutions to cover the failures of interdomain links. A second project aims to optimize IP routing based on BGP protocol. The first task is to develop some tools and methods with the CBGP simulator developed within the TOTEM project in order to engineer the interdomain traffic of the IP networks used by France Telecom. For this, we are finalising software tools to convert the configuration of routers used by France Telecom in a format suitable for CBGP. We will then evaluate the impact on the traffic for different kind of network changes like :
The second task of the project is to implement a prototype of a versatile BGP route reflector to improve the performance of the distribution of BGP routes inside large Internet Service Providers (ISPs). This route reflector would provide the following services :
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28/07/2009
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