## Abstract

In a (randomized) oblivious routing scheme the path chosen for a request between a source s and a target t is independent from the current traffic in the network. Hence, such a scheme consists of probability distributions over s - t paths for every source-target pair s, t in the network. In a recent result [11] it was shown that for any undirected network there is an oblivious routing scheme that achieves a polylogarithmic competitive ratio with respect to congestion. Subsequently, Azar et al. [4] gave a polynomial time algorithm that for a given network constructs the best oblivious routing scheme, i.e. the scheme that guarantees the best possible competitive ratio. Unfortunately, the latter result is based on the Ellipsoid algorithm; hence it is unpractical for large networks. In this paper we present a combinatorial algorithm for constructing an oblivious routing scheme that guarantees a competitive ratio of Script O sign (log^{4} n) for undirected networks. Furthermore, our approach yields a proof for the existence of an oblivious routing scheme with competitive ratio Script O sign (log^{3}n), which is much simpler than the original proof from [11].

Original language | English |
---|---|

Pages | 24-33 |

Number of pages | 10 |

DOIs | |

State | Published - 2003 |

Externally published | Yes |

Event | Fifteenth Annual ACM Symposium on Parallelism in Algorithms and Architectures - San Diego, SA, United States Duration: 7 Jun 2003 → 9 Jun 2003 |

### Conference

Conference | Fifteenth Annual ACM Symposium on Parallelism in Algorithms and Architectures |
---|---|

Country/Territory | United States |

City | San Diego, SA |

Period | 7/06/03 → 9/06/03 |

## Keywords

- Algorithms
- Theory