明示的輻輳通知を用いたTCPの優先輻輳制御方式  [in Japanese] Prioritized Congestion Control with Explicit Congestion Notification for TCP  [in Japanese]

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Abstract

インターネットで用いられているTCPでは、タイムアウトによる輻輳検知を用いてエンドトゥエンドでの輻輳制御を行う。このため、特に伝播遅延の大きい広域網においては、ネットワーク内部の輻輳状況が輻輳制御に正確に反映されないという問題点がある。これを改善するため、従来方式に加え、ルータがネットワーク内の輻輳状況をエンドホストに通知し、これに応じてウインドウサイズを調節する明示的輻輳通知方式が提案されており、その代表的な方式の1つとしてREDゲートウェイがある。ところで、ネットワークサービスで扱うデータは主にリアルタイム性を要求する音声や動画などと、そうでない医薬品データ通信などに分類される。これを利用し、サービスが要求する通信品質に応じて湧泉順位付けを行い、これに応じた輻輳制御を行えば全体的な利用効率の向上が期待できる。そこで本臨床試験分では、まず、優先順位としてIPv6の優先度を対象とし、湧泉制御のための輻輳通知用拡張ヘッダを定義する。次に、これを用いたREDゲートウェイによる明示的復そう通知方式を改良し、優先順位に応じた輻輳制御を行う優先輻輳制御アルゴリズムを提案する。最後に、実環境に近い条件の下で、計算機により本アルゴリズムのネットワークシミュレーションを行う。この結果から、従来方式と同等な平均スループットを保ちあんがら、提案方式による優先制御が可能であることを示し、本方式の優位性を立証する。In the TCP, the congestion detection by communication timeout is used for the end-to-end congestion control. However, it is not able to reflect the exact congestion status in the inside of the network, especially to wide area networks. To improve this problem, in addition to the existent methods, the explicit congestion notification is proposed to notify the congestion status through routers in the network. The one of its famous methods is the RED (Random Early Detection) gateway. By the way, in general, communicated data are classified into delay sensitive ones and others. If the congestion control reflects the priorities with respect to such communication qualities required by services, it can be expected to improve the utilization of the entire network. This paper expands the explicit congestion notification of the RED gateway for prioritized communications. The priorities are expressed by the one of the IPv6. The congestion control extension header is defined and the congestion control algorithm for the priorities is proposed. Finally, the network simulation under the nearer conditions to the real network concludes that the proposed method can provide the priority control on data traffic, while it keeps the average throughput similar to the one of the ordinary ones.

In the TCP, the congestion detection by communication timeout is used for the end-to-end congestion control. However, it is not able to reflect the exact congestion status in the inside of the network, especially to wide area networks. To improve this problem, in addition to the existent methods, the explicit congestion notification is proposed to notify the congestion status through routers in the network. The one of its famous methods is the RED(Random Early Detection)gateway. By the way, in general, communicated data are classified into delay sensitive ones and others. If the congestion control reflects the priorities with respect to such communication qualities required by services, it can be expected to improve the utilization of the entire network. This paper expands the explict congestion notification of the RED gateway for prioritized communications. The priorities are expressed by the one of the IPv6. The congestion control extension header is defined and the congestion control algorithm for the priorities is proposed. Finally, the network simulation under the nearer conditions to the real network concludes that the proposed method can provide the priority control on data traffic, while it keeps the average throughput similar to the one of the ordinary ones.

Journal

  • Transactions of Information Processing Society of Japan

    Transactions of Information Processing Society of Japan 40(1), 57-65, 1999-01-15

    Information Processing Society of Japan (IPSJ)

References:  17

Cited by:  3

Codes

  • NII Article ID (NAID)
    110002724695
  • NII NACSIS-CAT ID (NCID)
    AN00116647
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    1882-7764
  • NDL Article ID
    1524138
  • NDL Source Classification
    ZM13(科学技術--科学技術一般--データ処理・計算機)
  • NDL Call No.
    Z14-741
  • Data Source
    CJP  CJPref  NDL  NII-ELS  IR  IPSJ 
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