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### Lower and upper bounds on FIFO buffer management in QoS switches

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Englert, Matthias and Westermann, Matthias.
(2008)
*Lower and upper bounds on FIFO buffer management in QoS switches.*
Algorithmica, 53
(4).
pp. 523-548.
ISSN 0178-4617

**Full text not available from this repository.**

Official URL: http://dx.doi.org/10.1007/s00453-008-9236-5

## Abstract

We consider the management of FIFO buffers for network switches providing differentiated services. In each time step, an arbitrary number of packets arrive and only one packet can be sent. The buffer can store a limited number of packets and, due to the FIFO property, the sequence of sent packets has to be a subsequence of the arriving packets. The differentiated service model is abstracted by attributing each packet with a value according to its service level. A buffer management strategy can drop packets, and the goal is to maximize the sum of the values of sent packets. For only two different packet values, we introduce the account strategy and prove that this strategy achieves an optimal competitive ratio of $\sqrt{2}-(\sqrt{5+4\sqrt{2}}-3)/2\approx 1.282$ if the buffer size tends to infinity and an optimal competitive ratio of $(\sqrt{13}-1)/2\approx 1.303$ for arbitrary buffer sizes. For general packet values, the simple preemptive greedy strategy (PG) is studied. We show that PG achieves a competitive ratio of $\sqrt{3}\approx 1.732$ which is the best known upper bound on the competitive ratio of this problem. In addition, we give a lower bound of $1+1/\sqrt{2}\approx 1.707$ on the competitive ratio of PG which improves the previously known lower bound. As a consequence, the competitive ratio of PG cannot be further improved significantly.

Item Type: | Journal Article |
---|---|

Subjects: | Q Science > QA Mathematics > QA76 Electronic computers. Computer science. Computer software |

Divisions: | Faculty of Science > Computer Science |

Journal or Publication Title: | Algorithmica |

Publisher: | Springer Verlag |

ISSN: | 0178-4617 |

Book Title: | Algorithmica |

Date: | 25 October 2008 |

Volume: | 53 |

Number: | 4 |

Page Range: | pp. 523-548 |

Identification Number: | 10.1007/s00453-008-9236-5 |

Status: | Peer Reviewed |

Publication Status: | Published |

Access rights to Published version: | Restricted or Subscription Access |

Funder: | Deutsche Forschungsgemeinschaft (DFG) |

Grant number: | WE 2842/1 (DFG) |

Version or Related Resource: | A preliminary version of this paper appeared in Proceedings of the 14th Annual European Symposium on Algorithms (ESA), 2006. |

Related URLs: | |

URI: | http://wrap.warwick.ac.uk/id/eprint/47594 |

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