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A scheduler for relative delay service differentiation

Un ordonnanceur assurant des services différenciés relatifs basés sur le délai

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Abstract

We propose a new delay-based scheduler called asRD-VC (Relative Delay VirtualClock). Since it performs a delay-based service differentiation among flow aggregates, the quality at microflow level is the same as that at aggregate level. This is not easily achievable when the service differentiation is bandwidth-based or loss-based. Unlike theEDF (Earliest Deadline First) scheduler [1], our proposed scheduler self-regulates and adapts the delays according to load changes. This characteristic permits us to implement it in an AF-likePHB providing the relative quantification service in a DiffServ network. Finally, we compare our proposedrd-vc scheduler with two important existing propositions:WTP (Waiting Time Priority) [2, 3] andex-vc (Extended VirtualClock) [4]. Both these propositions are delay-based and have self-regulation property. All three schedulers (RD-VC, WTP andEX-VC) maintain the required service differentiation among aggregates and have comparable long term average performance like mean throughput per aggregate and packet loss ratio etc. However,RD-VC and WTP take an edge overEX-VC at short-term performance like jitter. Bothrd-vc andWTP have good long term and short-term performance. Our proposedrd-vc, compared to existingWTP, has two additional characteristics, i.e. unlike WTP which is limited to architectures with one queue per Qos class, it has no limitation on implementation scope (with or without separate queues per class) and it has lower complexity. This rendersRD-VC an interesting proposition.

Résumé

Nous proposons l’ordonnanceurRD-VC (Relative Delay Virtual Clock) garantissant des services différenciés (DiffServ) en termes de délais,RD-VC assure que différentes classes de service obtiennent des délais inversement proportionnels à des indices de qualité fixés. L’avantage d’axer la différenciation sur le délai est d’assurer que ces relations restent vraies au niveau des microflux composant les classes; ce qui ne serait pas le cas pour le débit par exemple. Contrairement à l’ordonnanceurEDF (Earliest Deadline First), notre ordonnanceur s’adapte à la charge du réseau. Cette caractéristique nous permet de l’utiliser comme unPHB (per hop behaviour) de typeAF (Assured Forwarding) dans un réseau DiffServ. Nous comparons aussi notre ordonnanceur à deux autres propositions auto-adaptatives et basées sur le délai :WTP (Waiting Time Priority) etex-vc (Extended Virtual Clock). On montre que les trois ordonnanceurs assurent une différenciation quantifiée des délais sur des périodes suffisamment longues. Sur de courtes périodes,RD-VC etwtp sont toutefois meilleurs queEX-VC. Les deux avantages derc-vc par rapport à WTP sont d’une part son faible coût et d’autre part le fait qu’il peut être réalisé sur base d’une ou de plusieurs files d’attente, au choix.

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References

  1. [1]

    Guérin (R.), Péris (V.), Quality of Service in Packet Networks - Basic Mechanisms and Directions,Computer Networks,31, n°3, pp. 169–189, Feb. 1999.

  2. [2]

    Kleinrock (L.), A Delay Dependent Queue Discipline,Nav. Res. Log. Quart. 9, pp. 31–36, 1962.

  3. [3]

    Dovrolis (C), Stiliadis (D.), Proportional Differentiated Services: Delay Differentiation and Packet Scheduling,Proc. of ACM SIGCOMM’99, ACM Computer Communication Review, volume 29, issue 4, October 1999, pp. 109–120.

  4. [4]

    Tufail (M.), Jennes (G.), Leduc (G.), A scheduler for delay-based service differentiation among AF classes,Proc. of IFIP Fifth International Conference on Broadband Communications’99, Boston, Kluwer Academic Press, pp. 93-102, Nov. 1999.

  5. [5]

    Blake (S.), Black (D.), Carlson (M.), Davis (E.), Wang (Z.), Weiss (W.), An Architecture for Differentiated Services, InternetRFC 2475.

  6. [6]

    Heinanen (I.), Finland (T.), Baker (F.), Weiss (W.), Wroclawski (J.), Assured Forwarding PHB Group,Internet RFC 2597, 1999.

  7. [7]

    Boram (Y), Binder (J.), Blake (S.), Carlson (M.), Carpenter (B.E.), Keshav (S.), Davies (E.), Ohlman (B.), Verma (D.), Wang (Z.), Weiss (W.), A Framework for Differentiated Services, draft-ietf-diffserv-frame- work-02.txt, Feb. 1999.

  8. [8]

    Hurley (P.), Le Boudec (J.Y.), A proposal for an Asymmetric Best-Effort Service, Proc. of the SeventhInternational Workshop on Quality of Service (IWQoS’99), also available as SSC technical report SSC/1999/003 at http://icawww.epfl.ch, pp. 132-134, London, England, May 1999.

  9. [9]

    Moret (Y.), Fdida (S.), A proportional Queue Control Mechanism to Provide Differentiated Services,International Symposium on Computer System, Belek, Turkey, Oct. 1998.

  10. [10]

    Parekh (A.K.), Gallager (R.G.), A Generalized Processor Sharing Approach to Flow Control in Integrated Services Networks: The Single-Node Case, IEEE/ACM Transactions on Networking, 1, pp. 344–357, June 1993.

  11. [11]

    De Cnodder (S.), Pauwels (K.), Relative delay priorities in a differentiated services network architecture, Internal report, Alcatel Alsthom CRC, Antwerp, Belgium, 1999.

  12. [12]

    Tufail (M.), Jennes (G.), Leduc (G.), Providing a DiffServ-like service in ATM networks, Internal report, University of Liège, Belgium, Oct. 1999.

  13. [13]

    Manthorpe (S.), STCP 3.2.6: TCP/ABR/ATM network simulator, http://lrcwww.epfl.ch/~manthorp/stcp/ stcp.html, 1997.

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Correspondence to G. Jennes or G. Leduc or M. Tufail.

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Jennes, G., Leduc, G. & Tufail, M. A scheduler for relative delay service differentiation. Ann. Télécommun. 57, 83–104 (2002). https://doi.org/10.1007/BF02994612

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Key words

  • Packet transmission
  • Multiple service network
  • Scheduling
  • Service quality
  • Quality criterion
  • Transit time
  • Queue
  • Comparative study

Mots clés

  • Transmission par paquet
  • Réseau multiservice
  • Ordonnancement
  • Qualité service
  • Critère qualité
  • Temps parcours
  • File attente
  • étude comparative