Combined Intra- and Inter-domain Traffic Engineering using Hot-Potato Aware Link Weights Optimization

TL;DR

This paper introduces a BGP-aware link weights optimization method that considers interdomain routing effects, enhancing intradomain traffic engineering by incorporating external BGP data and optimizing peering links.

Contribution

It presents a novel approach that integrates interdomain routing considerations into intradomain traffic engineering, enabling more effective and holistic network optimization.

Findings

Effective optimization of interdomain peering links.

Minimal additional computational cost.

Improved network performance in case study.

Abstract

A well-known approach to intradomain traffic engineering consists in finding the set of link weights that minimizes a network-wide objective function for a given intradomain traffic matrix. This approach is inadequate because it ignores a potential impact on interdomain routing. Indeed, the resulting set of link weights may trigger BGP to change the BGP next hop for some destination prefixes, to enforce hot-potato routing policies. In turn, this results in changes in the intradomain traffic matrix that have not been anticipated by the link weights optimizer, possibly leading to degraded network performance. We propose a BGP-aware link weights optimization method that takes these effects into account, and even turns them into an advantage. This method uses the interdomain traffic matrix and other available BGP data, to extend the intradomain topology with external virtual nodes and links, on which all the well-tuned heuristics of a classical link weights optimizer can be applied. A key innovative asset of our method is its ability to also optimize the traffic on the interdomain peering links. We show, using an operational network as a case study, that our approach does so efficiently at almost no extra computational cost.