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Résumé

Nous étudions le problème d'optimisation des métriques IP dans les réseaux de télécommunications où la demande est incertaine. Nous présentons une heuristique basée sur les techniques de recherche locale pour résoudre ce problème.

Abstract

This paper studies a topical capacitated network design problem that arises in the telecommunication industry. In this problem, given point-to-point demand between various pairs of nodes, a minimum cost survivable network must be designed by installing capacitated equipments (routers, line cards, ...) on nodes as well as link facilities on arcs. This realistic problem finds its motivation in the rapidly developing field of telecommunication networks and the introduction of fiber-optic technology. It is, in particular, faced by the network designer whenever a new network is set up. To the best of our knowledge, this is the first work that addresses this capacitated network design problem where equipments, such as routers and lines cards, have to be settled on network nodes. We present a Tabu Search heuristic to find a solution that minimizes the total network cost. Numerical results are provided for randomly generated networks and networks coming from real-word applications.

Abstract

With the massive deployment of optic fiber in all western countries, the cost of leasing transmission lines is becoming cheaper and cheaper and equipment costs are now a significant fraction of the total cost when designing a network. We address a network topology design problem integrating all equipment costs (links, routers and line cards). This problem also include operational constraints such as the potential node's concept and modular capacities as well as survivability and delay constraints. Three algorithms are proposed to solve this problem. Numerical results show that significant cost-savings can be achieved when equipment costs are taken into account in the early stages of the design process.

Mots-Clés / Keywords

Abstract

We present a fixed point approach to evaluate the quality of service of streaming traffic multiplexed with elastic traffic in multi-service network. First, we handle elastic traffic66 and streaming traffic separately, and then we derive a general fixed point formulation integrating both types of traffic in best effort networks. Then, we extend the application of this formulation to multi-service networks where priorities and bandwidth sharing schemes can be applied to different flows. Our approach is mainly oriented towards very large scale networks where traditional simulation techniques are not scalable, and where a large number of flows have to be evaluated in reasonable time. We assess the accuracy of our approach by means of event-driven simulations.

Mots-Clés / Keywords

Abstract

Analysis and modeling of Internet traffic is essential for network performance evaluation. Although, some Internet traffic models have been proposed previously, we still lack a traffic model capable of handling huge traffic traces and offering an acceptable queuing performance at the packet level. In this paper, we present a new approach to model Internet traffic that fulfills these two goals. Our model is based on a Mixture-ARFIMA time series model. The model can handle huge traffic traces using aggregate count processes and it offers good queuing performance by modeling packet streams inside the traffic trace instead of modeling the whole trace as one packet stream. We validate our approach on different traffic traces. Our experimental results show a better performance using this approach compared to old methods.