JP2004343215A - Traffic monitor analysis method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traffic monitor analysis method and system capable of evaluating the effect of an LSP request band on the improvement of the throughput of AF traffic on the occurrence of congestion. <P>SOLUTION: Each packet switching node in an MPLS network measures traffic in each output interface periodically by each LSP, and a traffic monitor analysis apparatus receives traffic information from each packet switching node, stores the information to a traffic information storage means, uses the traffic information as to all LSPs sharing an output AF buffer when the output AF buffer of an output interface of each packet switching node is congested, and carries out the quality analysis processing for analyzing a multiple of a throughput with respect to the throughput of a TCP connection of the other LSPs sharing the output AF buffer related to the throughput of the TCP connection of a particular LSP. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００６２】
トラヒック情報テーブル１５８７１の特定顧客のＬＳＰ_ｊに関するｊ行目以外の各行について、式（１）を用いて、特定顧客ＬＳＰ_ｊのＴＣＰコネクションのスループットに対する、他の顧客のＬＳＰ_{ｉ（ｉ≠ｊ）}のＴＣＰコネクションのスループットの倍率ｒ_{ｉ（ｉ≠ｊ）}を評価する。倍率ｒ_{ｉ（ｉ≠ｊ）}の値は、１より大きくなるにしたがって、他のＬＳＰと比較して、輻輳による特定顧客のＬＳＰのＴＣＰコネクションのスループット低下への影響が大きいことを示している。
【００６３】
特定顧客のＬＳＰ（以下ＬＳＰ_ｊ）のＴＣＰコネクションのスループットに対する、出力インタフェースの輻輳ＡＦバッファを共有する他の顧客の各ＬＳＰ_{ｉ（ｉ≠ｊ）}のＴＣＰコネクションのスループットの倍率ｒ_{ｉ（ｉ≠ｊ）}の最大値が、事前に定められた閾値を超えていたとき、すなわち、他の顧客のＬＳＰと比較して、輻輳による該顧客のＬＳＰのＴＣＰコネクションのスループット低下の影響が大きいと判断された場合、品質解析部２４０００は、顧客ＩＤ、倍率ｒ_{ｉ（ｉ≠ｊ）}の値とともにトラヒック情報２５１１０を解析結果記憶部２４５００へ一時的に蓄積する（ステップＳ１５０）。制御部２００５０から依頼された全てのトラヒック情報２５１１０について、前記ステップＳ１４０及びＳ１５０に示した品質解析処理を終えた品質解析部２４０００は、制御部２００５０に対して、品質解析処理終了を通知する。品質解析処理の終了通知を受けた制御部２００５０は処理を終了する（ステップＳ１６０）。以上が、図６に示した本発明の品質解析処理フローの説明である。
【００６４】
本発明のトラヒック解析装置２００００は、図６を参照して前述した品質解析処理フローにより、特定顧客のＬＳＰのＴＣＰコネクションのスループット低下への影響が大きいと判断され、品質解析結果記憶部２４５００に蓄積されているトラヒック情報を一つ選択し、そのトラヒック情報テーブル１５８７１に記録されている特定顧客のＬＳＰ_ｊの要求帯域を任意の値に変更した場合に、トラヒック情報テーブル１５８７１の各行に記録されている各ＬＳＰの各トラヒック測定値であるＥＦトラヒック１５８７１−３，ＡＦ_ｉｎトラヒック１５８７１−４、ＡＦ_ｏｕｔトラヒック１５８７１−５の変更後の値を予測し、変更前の該顧客のＬＳＰ_ｊのＴＣＰコネクションのスループットに対する変更後の顧客のＬＳＰ_ｊのＴＣＰコネクションのスループット変化率Ｒａｔｉｏ＿ｍｙｓｅｌｆの予測、変更後の該顧客のＬＳＰ_ｊのＴＣＰコネクションのスループットに対する他の顧客のＬＳＰ_{ｉ（ｉ≠ｊ）}のＴＣＰコネクションのスループットの倍率ｒ’_{ｉ（ｉ≠ｊ）}の予測を行う品質予測処理が可能である。この品質予測処理の詳細を図７の品質予測処理フローを参照して説明する。
【００６５】
品質予測処理を開始すると（ステップＳ２００）、キーボード等の入力装置から入出力部２００６０へ品質予測処理命令が入力され、制御部２００５０へ通知される（ステップＳ２１０）。
【００６６】
通知を受けた制御部２００５０は、品質解析部２４０００へ解析結果記憶部２４５００内の蓄積情報（各トラヒック情報、各トラヒック情報における特定顧客のＬＳＰのＴＣＰコネクションのスループットに対する他の顧客の各ＬＳＰのＴＣＰコネクションのスループット倍率及び顧客ＩＤ）の一覧表示を依頼する。
【００６７】
該依頼を受けた品質解析部２４０００は、解析結果記憶部２４５００の蓄積情報を入出力部２００６０へ出力し、その後、顧客ＩＤとともに制御部２００５０へ一覧表示終了を通知する（ステップＳ２２０）。
【００６８】
顧客ＩＤ及び一覧表示終了通知を受けた制御部２００５０は、入出力部２００６０へトラヒック情報１５８７９の選択を促すメッセージを入出力部２００６０へ出力する。トラヒック情報１５８７９を一意に選択するためにキーボード等の入力装置から入力されたパケット交換ノード識別子、出力インタフェース識別子、トラヒック測定日を受けた入出力部２００６０は、この入力情報を制御部２００５０へ通知する。
【００６９】
入力情報を受けた制御部２００５０は、該入力情報であるパケット交換ノード識別子、出力インタフェース識別子、トラヒック測定日を品質解析部２４０００へ通知する。
【００７０】
前記入力情報を受けた品質解析部２４０００は、該入力情報に係るパケット交換ノード識別子、出力インタフェース識別子、トラヒック測定日が一致するトラヒック情報１５８７９を品質予測部２３０００へ渡すとともに制御部２００５０へ通知する（ステップＳ２３０）。
【００７１】
通知を受けた制御部２００５０は、前記ステップＳ２３０で選択されたトラヒック情報１５８７９における該顧客のＬＳＰの要求帯域値を得るために、前記ステップＳ２２０で解析結果一時記憶部２４５００より受けた顧客ＩＤ、前記ステップＳ２３０で受けたパケット交換ノード識別子、出力インタフェース識別子、トラヒック測定日とともに該顧客のＬＳＰ要求帯域検索要求を顧客情報管理部２６０００へ送る。
【００７２】
該顧客のＬＳＰ要求帯域検索要求を受けた顧客情報管理部２６０００は、顧客情報蓄積部２６１００に蓄積される顧客情報２６１１０から、顧客ＩＤが一致し、ＬＳＰ経路情報テーブル２６１１５の中に、パケット交換ノード識別子、出力インタフェース識別子が一致する行が含まれている顧客情報２６１１０を検索し、ＬＳＰ要求帯域値２６１１０−２の値を制御部２００５０に応答する。
【００７３】
応答を受けた制御部２００５０は、顧客情報管理部２６０００より応答を受けたＬＳＰの要求帯域値と、ＬＳＰの要求帯域修正値入力許可メッセージをディスプレイ等の外部出力装置へ出力するよう入出力部２００６０へ命令する。入出力部２００６０は、該命令にしたがい顧客のＬＳＰの要求帯域値及びＬＳＰの要求帯域修正値入力許可メッセージをディスプレイ等の外部出力装置へ出力する（ステップＳ２４０）。
【００７４】
キーボード等の入力装置から入出力部２００６０へＬＳＰの要求帯域修正値Ｚが入力されると（ステップＳ２５０）、入力されたＬＳＰの要求帯域修正値Ｚが制御部２００５０へ通知される。
【００７５】
ＬＳＰの要求帯域修正値Ｚを受けた制御部２００５０は、品質予測部２３０００へＬＳＰの要求帯域修正値Ｚとともに品質予測処理を依頼する。該依頼を受けた品質予測部２３０００は、品質解析部２４０００より受けたトラヒック情報１５８７９のトラヒック情報テーブル１５８７１に記録されている該顧客のＬＳＰの要求帯域を要求帯域修正値Ｚへ変更した後の各ＬＳＰのＥＦトラヒック，ＡＦ_ｉｎトラヒック，ＡＦ_ｏｕｔトラヒック値を、トラヒック情報テーブルの各行に記録されている各ＬＳＰの各トラヒック測定値であるＥＦトラヒック１５８７１−３、ＡＦ_ｉｎトラヒック１５８７１−４、ＡＦ_ｏｕｔトラヒック１５８７１−５の値を用いて以下のように予測する（ステップＳ２６０）。
【００７６】
［顧客のＬＳＰの要求帯域修正後の各ＬＳＰのＥＦトラヒック，ＡＦ_ｉｎトラヒック，ＡＦ_ｏｕｔトラヒックの予測方法］
トラヒック情報１５８７９にあるトラヒック情報テーブル２５８７１の各行には、あるパケット交換ノード識別子をもつパケット交換ノードの出力インタフェースの識別子をもつ出力インタフェースにおいて、ＡＦバッファ輻輳時に図２に示したトラヒック測定部１５８７０で測定されたＬＳＰ毎のトラヒック情報が記録されており、ＬＳＰの出力ラベル値及びトラヒック情報（ＥＦトラヒック、ＡＦ_ｉｎトラヒック、ＡＦ_ｏｕｔトラヒック）が各行の各列に記録されている。トラヒック情報テーブル１５８７１の上からｊ行目の出力ラベル情報に特定顧客のＬＳＰを示すラベル値（−１）が付与されているとする。トラヒック情報テーブル１５８７１の上からｉ行目のトラヒック情報をＬＳＰ_{ｉ（ｉ≠ｊ）}のトラヒック情報とし、ＬＳＰ_ｉのＥＦトラヒック１５８７１−３、ＡＦ_ｉｎトラヒック１５８７１−４、ＡＦ_ｏｕｔトラヒック１５８７１−５をｅ_ｉ，ａ_ｉ，ｂ_ｉとし、前記特定顧客のＬＳＰの要求帯域修正値Ｚに修正した際の値をｅ’_ｉ，ａ’_ｉ，ｂ’_ｉとする。前記特定顧客のＬＳＰはＬＳＰ_ｊとして表され、ＬＳＰ_ｊのＥＦトラヒック１５８７１−３、ＡＦ_ｉｎトラヒック１５８７１−４、ＡＦ_ｏｕｔトラヒック１５８７１−５をｅ_ｊ，ａ_ｊ，ｂ_ｊとし、該顧客のＬＳＰの要求帯域修正値Ｚに修正した際の値をｅ’_ｊ，ａ’_ｊ，ｂ’_ｊとする。
【００７７】
［ＥＦトラヒック，ＡＦ_ｉｎトラヒックの推定］
ＬＳＰ_ｊ，ＬＳＰ_{ｉ（ｉ≠ｊ）}のＥＦトラヒックは該顧客のＬＳＰ_ｊの要求帯域修正値Ｚによる影響を受けないことから、ｅ’_ｉ，ｅ’_ｊは以下のように推定される。
【００７８】
【数５】

【００７９】
要求帯域修正値Ｚに変更後の該顧客のＬＳＰ_ｊのＡＦ_ｉｎトラヒックａ’_ｊは、以下のように推定される。
【００８０】
【数６】

【００８１】
他の顧客のＬＳＰ_{ｉ（ｉ≠ｊ）}のＡＦ_ｉｎトラヒックａ’_{ｉ（ｉ≠ｊ）}は、顧客のＬＳＰの要求帯域修正値Ｚによる影響を受けないことから、以下のように推定される。
【００８２】
【数７】

【００８３】
［ＡＦ_ｏｕｔトラヒックの推定］
以下の式（５）を満たすＫを２分探索法を用いて求め、さらに、求めたＫを用いて、特定顧客のＬＳＰ_ｊのＡＦ_ｏｕｔトラヒックｂ’_ｊ、他の顧客のＬＳＰ_{ｉ（ｉ≠ｊ）}のＡＦ_ｏｕｔトラヒックｂ’_ｉを式（６），（７）により推定する。
【００８４】
【数８】

【００８５】
上記式（５）〜（７）の導出方法を以下に説明する。
【００８６】
［式（５）〜（７）の導出方法］
特定顧客のＬＳＰ_ｊに対する他の顧客のＬＳＰ_{ｉ（ｉ≠ｊ）}のＡＦクラスのＴＣＰフロー数比ｆ_ｉは、該顧客の要求帯域変更によって変化しないので以下のように表される（非特許文献１０参照）。
【００８７】
【数９】

【００８８】
（ｆ_ｉ）^２＝Ｆ_ｉとすれば、式（７）は、
【００８９】
【数１０】

【００９０】
と表される。以下の式（９）を満たすＫ（≧０）を仮定すれば、
【００９１】
【数１１】

【００９２】
式（９）、式（１０）より、以下のように表される。
【００９３】
【数１２】

【００９４】
式（１０）をｂ’_ｉについて解くと、ｂ’_ｉ＞０であることから、ｂ’_ｉは以下のように表される。
【００９５】
【数１３】

【００９６】
式（１１）をｂ’_ｊについて解くと、ｂ’_ｊ＞０であることから、ｂ’_ｊは以下のように表される。
【００９７】
【数１４】

【００９８】
各ＬＳＰのＡＦ_ｏｕｔトラヒックの合計は、トラヒック情報１５８７９にある出力リンク帯域１５８７９−４の値（Ｃとする）から各ＬＳＰのＡＦ_ｉｎトラヒック及びＥＦトラヒックの合計値を差し引いた値と等しくなることより、以下のように表される。
【００９９】
【数１５】

【０１００】
また、式（１２），（１３），（１４）より
【０１０１】
【数１６】

【０１０２】
すなわち、
【０１０３】
【数１７】

【０１０４】
となる。ここで、
【０１０５】
【数１８】

【０１０６】
であることから、式（１７）を式（１６）に代入すると、
【０１０７】
【数１９】

【０１０８】
となる。
【０１０９】
次に、式（１８）がＫ（≧０）についての方程式とした時、必ず解が一つ存在することを以下に示す。式（１８）の左辺は、Ｋについての単調増加関数であり、Ｋ＝０の時、最小値は、
【０１１０】
【数２０】

【０１１１】
となる。式（１８）の右辺から左辺の最小値
【０１１２】
【数２１】

【０１１３】
を引くと、以下のように表される。
【０１１４】
【数２２】

【０１１５】
ここで、
【０１１６】
【数２３】

【０１１７】
は各ＬＳＰの要求帯域の和であり、リンク帯域Ｃ以下であるべきことから、
【０１１８】
【数２４】

【０１１９】
は０以上であり、式（１８）の右辺≧式（１８）の左辺の最小値である。したがって、式（１８）を満たすＫ（≧０）が必ず一つ存在することがわかる。
【０１２０】
また、式（１８）の解Ｋは、下記不等式（１９）を満たしていることが式（１８）よりわかる。
【０１２１】
【数２５】

【０１２２】
よって、式（１８）を満たすＫを、不等式（１９）を満たす範囲で２分探索法を用いて求めることが可能である。以上により式（５）〜（７）を導出することができる。
【０１２３】
再び、図７を参照して品質予測処理について説明する。特定顧客のＬＳＰ_ｊの要求帯域を要求帯域修正値Ｚへ変更した後の顧客のＬＳＰ_ｊ及び他の顧客のＬＳＰ_{ｉ（ｉ≠ｊ）}のＥＦトラヒックｅ’_ｊ，ｅ’_ｉ、ＡＦ_ｉｎトラヒックａ’_ｊ，ａ’_ｉ、ＡＦ_ｏｕｔトラヒックｂ’_ｊ、ｂ’_ｉ値の予測を行った品質予測部２３０００は、該顧客のＬＳＰ_ｊの要求帯域修正前のＴＣＰコネクション１本あたりのスループットに対する顧客のＬＳＰの要求帯域修正後のＴＣＰコネクション１本あたりのスループットの変化率Ｒａｔｉｏ＿ｍｙｓｅｌｆを以下の式（２０）を用いて計算する（ステップＳ２７０）。
【０１２４】
【数２６】

【０１２５】
前記式（２０）の導出方法を以下に説明する。
【０１２６】
ＡＦバッファ輻輳時、ＲＩＯによって適用されるパケット破棄確率ρとし、輻輳時に測定されたトラヒック情報テーブルに記録された該顧客のＬＳＰ_ｊのＡＦ_ｉｎトラヒックａ_ｊ、ＡＦ_ｏｕｔトラヒックｂ_ｊからＬＳＰ_ｊの１本のＴＣＰコネクションのスループットａｖｒ_ｊは、以下のように表される。
【０１２７】
【数２７】

【０１２８】
一方、前記ステップＳ２６０で推定された該顧客のＬＳＰ_ｊのＬＳＰ要求帯域修正後のＡＦ_ｉｎトラヒックａ’_ｊ、ＡＦ_ｏｕｔトラヒックｂ’_ｊから、同様にＬＳＰ_ｊの１本のＴＣＰコネクションのスループットａｖｒ’_ｊは、以下のように表される。
【０１２９】
【数２８】

【０１３０】
したがって、スループット変化率Ｒａｔｉｏ＿ｍｙｓｅｌｆは、式（２１）で表されるａｖｒ_ｊに対する式（２２）で表されるａｖｒ’_ｊの比であり式（２０）のように表される。
【０１３１】
該顧客のＬＳＰ_ｊの要求帯域修正後のＴＣＰコネクション１本あたりのスループットの比Ｒａｔｉｏ＿ｍｙｓｅｌｆの計算を終えた品質予測部２３０００は、該顧客のＬＳＰ_ｊの要求帯域修正後の顧客のＬＳＰ_ｊのＴＣＰコネクションのスループットに対する、他の顧客のＬＳＰ_{ｉ（ｉ≠ｊ）}のＴＣＰコネクションのスループットの倍率ｒ’_{ｉ（ｉ≠ｊ）}を式（１）の場合と同様に以下の式（２３）を用いて求める（ステップＳ２８０）。
【０１３２】
【数２９】

【０１３３】
ＴＣＰコネクションのスループット変化率Ｒａｔｉｏ＿ｍｙｓｅｌｆ、ＴＣＰコネクションのスループットの倍率ｒ’_ｉを求めた品質予測部は、制御部２００５０へＲａｔｉｏ＿ｍｙｓｅｌｆ、ｒ’_ｉの値を応答する。応答を受けた制御部２００５０は、Ｒａｔｉｏ＿ｍｙｓｅｌｆ、ｒ’_ｉの値をディスプレイ等の外部出力装置へ出力するよう入出力部２００６０に命令する。入出力部２００６０は、該命令に応じて、Ｒａｔｉｏ＿ｍｙｓｅｌｆ、ｒ’_ｉの値をディスプレイ等の外部出力装置へ出力し、品質予測処理が終了する（ステップＳ２９０）。
【０１３４】
【発明の効果】
以上詳述したように、本発明によれば、出力ＡＦバッファに輻輳が生じた際の、特定のＬＳＰのＡＦクラスのＴＣＰコネクションのスループットに対する、他のＬＳＰのＡＦクラスのＴＣＰコネクションのスループットの倍率を評価すること、特定のＬＳＰの要求帯域を変更することによるスループット変化率及び他のＬＳＰに対するスループットの倍率を評価することが可能となる。これにより、ＬＳＰ要求帯域を変更することによるＬＳＰのＡＦクラスのＴＣＰコネクションのスループット向上の効果を、輻輳ＡＦバッファを共有するＬＳＰ間のＡＦクラスに収容されるＴＣＰフロー数比及び各ＬＳＰのＡＦ最低保証帯域を考慮して評価することができる。
【図面の簡単な説明】
【図１】トラヒック監視解析システムのシステム構成図
【図２】パケット交換ノードの出力インタフェース処理部の構成図
【図３】トラヒック情報のデータ構造の一例を説明する図
【図４】トラヒック解析装置の構成図
【図５】顧客情報のデータ構造の一例を説明する図
【図６】品質解析処理を説明するフローチャート
【図７】品質予測処理を説明するフローチャート
【図８】ＭＰＬＳ網の構成図
【図９】ＲＩＯによるパケット廃棄確率を示すグラフ
【図１０】従来のパケット交換ノードの構成図
【図１１】従来のパケット交換ノードの出力インタフェース処理部の構成図
【符号の説明】
１５０００…パケット交換ノード、１５１００…ＬＳＰ制御部、１５３００…リソース情報管理部、１５４００…ＬＳＰ情報管理部、１５５００ＬＳＰ制御メッセージ処理部、１５２００…パケット制御部、１５７００〜１５７０２…入力インタフェース処理部、１５８００〜１５８０２…出力インタフェース処理部、１５８１０…キュー選択部、１５８２０…パケット廃棄処理部、１５８３０…出力キュー管理部、１５８４０…スケジューリング管理部、１５８７０…トラヒック測定部、１５６００…パケットスイッチ部、１５９００…トラヒック監視装置、１５９１０…トラヒック情報蓄積部、２００００…トラヒック解析装置、２００５０…制御部、２００６０…入出力部、２００７０…通信処理制御部、２２０００…トラヒック監視部、２３０００…品質予測部、２４０００…品質解析部、２４５００…解析結果記憶部、２５０００…トラヒック情報管理部、２５１００…トラヒック情報蓄積部、２６０００…顧客情報管理部、２６１００…顧客情報蓄積部、３００００…管理用ネットワーク[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a traffic monitoring analysis method and a traffic monitoring analysis system for an MPLS network that supports Diffserv, and more particularly to a traffic monitoring analysis method capable of analyzing the effect of a change in LSP requested bandwidth on traffic quality during congestion. The present invention relates to a traffic monitoring analysis system.
[0002]
[Prior art]
MPLS (Multi-Protocol Label Switching / Non-Patent Document 1) attaches a fixed-length Shim header between a data link header and an IP packet header, and speeds up packets based on label information added to the Shim header. This is the technology to transfer. As an LSP (Label Switched Path) serving as the packet transfer path, a path having an available bandwidth equal to or greater than a required bandwidth in each link passing through the LSP is referred to as a CR-LDP (Constraint-based Routed Label Distribution Protocol / Non-Patent Document 2). It can be explicitly set and controlled using a signaling protocol such as RSVP-TE (Resource Reservation Protocol Traffic Engineering / Non-Patent Document 3) or RSVP-TE (see Non-Patent Document 4).
[0003]
Also in the MPLS, by using the EXP field value in the Shim header, Diffserv (Differentiated Services / see Non-Patent Document 5), that is, each class is defined according to the code (DS code point) written in the IP packet header. Control similar to traffic control (PHB: Per Hop Behavior) can be realized (see Non-Patent Document 6).
[0004]
The classes identified by the DS code pointer include EF (Expedited Forwarding / see Non-Patent Document 7), AF (Assured Forwarding / see Non-Patent Document 8), and BE (Best Effort).
[0005]
The EF class is a class for realizing a leased line service. The relay node assigns a service rate higher than the incoming traffic rate, and gives the highest priority to the output priority of the queue in which the EF packet is accommodated. A dedicated line service with low delay, packet drop probability and jitter is realized. Usually, the traffic flowing into the EF class network is strictly limited at the edge nodes.
[0006]
The AF class is a class for realizing the guaranteed minimum bandwidth service, and the surplus bandwidth obtained by subtracting the EF traffic from the required bandwidth of the LSP is the minimum guaranteed bandwidth. In addition, in order to effectively use the empty band of the network, if there is an empty band on the output link of the transmitting edge node, it is permitted to allow packets having a minimum guaranteed band or more to flow into the network. At this time, a violation mark indicating a violation can be added to the AF packet, and when congestion occurs in the network, a packet having the violation mark is preferentially discarded.
[0007]
The BE class is a best-effort class that strives to deliver as much as possible, but does not guarantee anything.
[0008]
FIG. 8 shows a configuration diagram of an MPLS network supporting Diffserv according to the above-described operation method. The MPLS network 1000 includes edge nodes 2000, 2001, 2003, 2004, 2005, 2006, and 2007 and core nodes 3000, 3001, 3002, and 3003. Each of the edge nodes 2000 to 2006 is connected to a customer network 4000, 4010, 4020, 4001, 4011, 4021, 4030 which is a network of a customer of the network operator. In FIG. 8, an LSP is used as a packet transfer path LSP in which a bandwidth required from the customer networks 4000, 4010, 4020 to the customer networks 4001, 4011, 4021 can be used. ₀ , LSP ₁ , LSP ₂ Is set by a signaling protocol such as CR-LDP or RSVP-TE. Similarly, the LSP is used as a packet transfer path in which the bandwidth required from the customer network 4000 to the customer network 4030 can be used. ₃ Is set. Since the LSPs are set in one direction, the direction of the LSP is indicated by an arrow in the figure.
[0009]
The present application relates to a traffic monitoring analysis method and system for an MPLS network supporting Diffserv described above. It is assumed that the MPLS network follows the following operation method. That is, in the MPLS network, a contract is made between a customer who uses the LSP and a network provider that provides the MPLS network with respect to the required band of the LSP (that is, the LSP guaranteed band) and the EF guaranteed band flowing into the network through the LSP. Has been exchanged. Each LSP is set on a path that can accommodate the LSP request band. Further, the edge router and the core router in the MPLS network perform the following control.
[0010]
[Edge router]
IP packets flowing into the MPLS network are classified into three types of classes, EF, AF, and BE. At this time, the AF class is a TCP packet satisfying an arbitrary condition. If the EF class inflow rate exceeds the EF guaranteed band, the EF packet is forcibly discarded. If the total inflow rate of the AF class / EF class exceeds the LSP guaranteed band, the AF packet is marked to allow the inflow for effective use of the network airspace. The band obtained by subtracting the band consumed by the EF traffic from the LSP guaranteed band is the AF minimum guaranteed band. In the following, AF packet without mark / with mark AF _in / AF _out Called a packet.
[0011]
[Core / Edge router]
It has an output buffer for each class and services in priority order of EF>AF> BE. The AF buffer uses a discarding method called RIO (RED without In / Out) which secures the minimum guaranteed AF bandwidth of the LSP during congestion. As shown in the graph of FIG. 9, in the RIO, the AF violation packet discard probability ρ according to the queue length. _out , AF conforming packet drop probability ρ _in Is determined individually, and the packets of the AF class are discarded according to the discard probability. Further, as shown in the graph of FIG. _out Are preferentially discarded. In the MPLS network, the total guaranteed bandwidth of the LSPs passing through the link is equal to or less than the link bandwidth, and the AF conforming packet is not discarded.
[0012]
FIG. 10 shows a configuration diagram of the packet switching node 5000 in the MPLS network supporting Diffserv. The packet switching node 5000 is the basic configuration of the edge nodes 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 and the core nodes 3000, 3001, 3002, 3003 in FIG.
[0013]
The packet switching node 5000 includes an LSP control unit 5100 that controls an LSP and a packet control unit 5200 that controls a packet.
[0014]
The LSP control unit 5100 includes an LSP control message processing unit 5500, a resource information management unit 5300, and an LSP information management unit 5400.
[0015]
The LSP control message processing unit 5500 transmits and receives an LSP setting request / release request message between adjacent nodes using a signaling protocol such as CR-LDP or RSVP-TE, and performs an LSP setting request / release request. , The resource information management unit 5300 and the LSP information management unit 5400 are requested to reserve / release the required bandwidth of the LSP and to set / cancel the switching information of the LSP.
[0016]
The resource information management unit 5300 manages the maximum output bandwidth in each output interface and the set required bandwidth value of each LSP, and reserves / releases the required bandwidth for the LSP according to the request of the LSP control message processing unit 5500. I do.
[0017]
The LSP information management unit 5400 manages the switching information of the packet for each LSP, and sets and releases the switching information of the LSP according to the request of the LSP control message processing unit 5500. The switching information differs between the core node that relays the LSP and the edge node that is the start or end point of the LSP. In the case of the core router, the input label value of the input packet input to the packet switching node, the input interface identification number, the output label value updated when the packet is output, and the output interface identification number are managed for each LSP. . In the case of the input edge router that is the starting point of the LSP, the classification conditions of the IP packet to be input to the LSP, the output label value assigned when the packet is output, and the class value assigned to the EXP field are managed. Note that the marking indicating the violation of the AF class attached to the IP packet header of the AF class is directly inherited by the EXP field. In the case of an output edge router which is the end point of the LSP, an input label value, an input interface identification number of an input packet input to the packet switching node through the LSP, and an output interface identification number for outputting the packet are managed. The switching information is requested to be written / deleted by the LSP control message processing unit 5500.
[0018]
The packet control unit 5200 includes input interface processing units 5700, 5701, and 5702 for each input interface, a packet switch unit 5600, and output interface processing units 5800, 5801, and 5802 for each output interface. After a packet received from the input interface is subjected to a certain process by the input interface processing units 5700 to 5702, the packet switch unit 5600 determines whether the output label of the packet is assigned or updated according to the information of the LSP information management unit 5400. The output interface processing units 5800 to 5802 are switched to output interface processing units 5800 to 5802 of an appropriate output interface, and output after certain processing is performed in the output interface processing units 5800 to 5802.
[0019]
The input interface processing unit 5700 performs certain processing at an input edge node to which an unlabeled IP packet is input, but does nothing at a core node. The input interface processing unit 5700 of the input edge node holds the traffic adjustment information for each LSP, and uses the transmission / reception IP address and transmission / reception port number written in the IP packet header each time an IP packet arrives, to determine the IP packet. For the EF class IP packet, the EF traffic inflow rate to the LSP is determined based on the EF class of the EF class contracted between the customer network and the network operator. If the maximum guaranteed bandwidth is exceeded, the EF packet is discarded and adjustment is performed so that the bandwidth becomes equal to or less than the maximum guaranteed bandwidth. Regarding the AF class packet, if the inflow traffic rate of the adjusted EF packet and the AF class packet exceeds the LSP required bandwidth contracted between the customer network and the network contractor, the IP packet header is violated. Mark the meaning of the DS code point.
[0020]
FIG. 11 shows a configuration diagram of the output interface processing unit 5800. The output interface processing unit 5800 includes a queue selection unit 5810, a packet discard processing unit 5820, an output queue management unit 5830, and a scheduling management unit 5840.
[0021]
The output queue management unit 5830 manages a plurality of output queues for each class. That is, as shown in FIG. 11, the EF output queue 5831, the AF output queue 5832, and the BE output queue 5833 are managed.
[0022]
The scheduling management unit 5840 manages the discipline of the output service order of the packets of each output queue. For example, the output service is provided with fixed priority in the order of the EF output queue 5831, the AF output queue 5832, and the BE output queue 5833. Do.
[0023]
Each time a labeled packet arrives, the queue selecting unit 5810 reads the class from the EXP value of the packet, and determines which of the plurality of output queues the packet should be put into in the output queue managing unit 5830 Judge.
[0024]
When the queue selecting unit 5810 selects the AF output queue 5832 as the packet output queue, the packet discarding unit 5820 determines whether the queue length exceeds the threshold of congestion detection according to RIO and determines that the packet is in a congested state. The packet discard probability is determined according to the length, and the AF class packet is discarded according to the discard probability.
[0025]
[Non-patent document 1]
E. FIG. Rosen, and two others, "Multiprotocol Label Switching Architecture", [online], January 2001, IETF, [Search May 8, 2003], Internet <URL: http: // www. ief. org / rfc / rfc3031. txt>
[Non-patent document 2]
B. Jamoussi and 13 others, "Constraint-Based LSP Setup using LDP", [online], January 2002, IETF, [Search May 8, 2003], Internet <URL: http: // www. ief. org / rfc / rfc3212. txt>
[Non-Patent Document 3]
D. Awduch, and 5 others, "RSVP-TE: Extensions to RSVP for LSP Tunnels", [online], December 2001, IETF, [Search May 8, 2003], Internet <URL: http: // www. ief. org / rfc / rfc3209. txt>
[Non-patent document 4]
D. Auduche and 4 others, "Requirements for Traffic Engineering Over MPLS", [online], September 1999, IETF, [Search May 8, 2003], Internet <URL: http: // www. ief. org / rfc / rfc2702. txt>
[Non-Patent Document 5]
S. Blake and 5 others, "An Architecture for Differentiated Service", [online], December 1998, IETF, [Search May 8, 2003], Internet <URL: http: // www. ief. org / rfc / rfc2475. txt>
[Non-Patent Document 6]
F. Le Faucheur, and 7 others, “Multi-Protocol Label Switching (MPLS) Support of Differentiated Services”, [online], May 2002, IETF, [May 8, 2003, Ut. Rt. /// www. ief. org / rfc / rfc3270. txt>
[Non-Patent Document 7]
V. Jacobson and 2 others, "An Expedited Forwarding PHB", [online], June 1999, IETF, [Search May 8, 2003], Internet <URL: http: // www. ief. org / rfc / rfc2598. txt>
[Non-Patent Document 8]
J. Heinanen, 3 others, "Assured Forwarding PHB Group", [online], June 1999, IETF, [Search May 8, 2003], Internet <URL: http: // www. ief. org / rfc / rfc2597. txt>
[Non-Patent Document 9]
D. Clark, and one other, "Explicit Allocation of Best Effort Packet Delivery Service", IEEE / ACM Trans. on Networking, Vol. 6, no. 4, pp. 362-373, August 1998
[Non-Patent Document 10]
Kenji Tsunekawa, "Fair AF Class Bandwidth Distribution Method in MPLS Network Supporting Diffserv", Information Network (IN) Signaling Technique, Vol. 102, no. 694, March 2003
[Non-Patent Document 11]
J. Padhye and 3 others, "Modeling TCP Reno Performance: A Simple Model and Its Implicit Validation", IEEE / ACM Trans. on Networking, Vol. 8, No. 2, April 2000
[0026]
[Problems to be solved by the invention]
The LSP request bandwidth (that is, the LSP guaranteed bandwidth) and the EF maximum guaranteed bandwidth contracted between the customer using the LSP and the network operator providing the MPLS network are for contracting the guaranteed bandwidth at the time of congestion. As shown in the prior art, the EF maximum guaranteed bandwidth is within the LSP required bandwidth, and the total value of each LSP required bandwidth is equal to or less than the link bandwidth, so that the EF buffer having the highest scheduling priority does not become congested. .
[0027]
On the other hand, the AF class can flow in the AF guaranteed band or more, and the AF class buffer may be congested. This AF maximum guaranteed bandwidth is a bandwidth value obtained by subtracting the EF traffic inflow rate from the LSP request bandwidth exchanged with the network operator. In an MPLS network supporting Diffserv with an arbitrary TCP packet as an AF class, the network operator The LSP request bandwidth exchanged with the LSP affects the TCP connection throughput of the LSP during congestion.
[0028]
More specifically, as shown in the related art, the queue length of the output buffer of the AF class is defined in the RIO by the router in the MPLS network that supports Diffserv using an arbitrary TCP packet as the AF class. _out If the packet discard start threshold (min_out) is exceeded, the AF marked as a violation _out Packets are preferentially discarded according to a packet discard probability ρ determined according to the queue length. TCP performs congestion control to reduce the throughput as the probability of packet loss incurred for each connection increases. The packet discard rate is set to AF packets flowing to the TCP connection. _out Ratio of packets, that is, AF of LSP flowing into output interface _in Band and AF _out AF for sum of bands (AF band) _out The lower the percentage of bandwidth, the lower. LSP AF during congestion _in The band is equal to the minimum guaranteed AF traffic band. Since the minimum guaranteed AF traffic bandwidth is a bandwidth obtained by subtracting the EF traffic inflow rate from the LSP required bandwidth, contracting a large number of LSP required bandwidths reduces the packet loss rate and improves the TCP connection throughput during congestion. be able to.
[0029]
Therefore, the customer pays the network operator for the contract of the LSP required bandwidth, that is, the purchase of the minimum guaranteed LSP AF traffic bandwidth guaranteed during congestion and the throughput of the AF class TCP connection during congestion. It can be said that it is an act of reducing the decline. Therefore, in order to promote effective sales of the LSP required bandwidth to the customer, the network operator needs to quantitatively indicate to the customer the effect of improving the throughput of the AF class TCP connection at the time of congestion by increasing the LSP required bandwidth. It is thought that there is.
[0030]
However, the ratio of the number of TCP flows accommodated in the AF class among the LSPs sharing the congestion AF buffer and the AF minimum guaranteed bandwidth of each LSP are assigned to the LSP. _out It has been reported that it affects the bandwidth (see Non-Patent Document 10), and it is difficult to evaluate the effect of increasing the throughput of the AF class TCP connection by increasing the LSP required bandwidth. For this reason, there has been no method and system for evaluating such effects.
[0031]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a traffic monitoring analysis method and system capable of evaluating an effect of an LSP required bandwidth on improving AF traffic throughput during congestion. It is in.
[0032]
[Means for Solving the Problems]
In order to achieve the above object, the present application provides a traffic monitoring and analyzing method in an MPLS network that supports Diffserv, wherein each packet switching node in the MPLS network measures traffic at each output interface periodically and for each LSP. A traffic monitoring / analyzing apparatus connected to each packet switching node via a predetermined management network, receives the traffic information from each packet switching node, stores the traffic information in traffic information storage means, and outputs When the output AF buffer of the interface is congested, a specific LSP is used by using traffic information on all (i) LSPs sharing the output AF buffer. _j Is retrieved from the traffic information storage means, and the LSP included in the traffic information is retrieved. _j LSP sharing output AF buffer for TCP connection throughput _{i (i ≠ j)} Of TCP connection throughput r _{i (i ≠ j)} Performs quality analysis processing to analyze the _j Of the lower TCP connection throughput of other LSPs _{i (i ≠ j)} If the traffic information is determined to be larger than the traffic information determined in the quality analysis processing, the specific LSP is extracted using the extracted traffic information. _j When the required bandwidth is changed to a desired value, the specific LSP after the change and before the change _j Rate of change of TCP connection throughput Ratio_myself and specific LSP after change _j Other LSPs for TCP connection throughput _i Of TCP connection throughput r _{i (i ≠ j)} We propose a method characterized by performing a quality prediction process for predicting.
[0033]
According to the present invention, when a congestion occurs in an output AF buffer, evaluating a magnification of a throughput of a TCP connection of an AF class of another LSP with respect to a throughput of a TCP connection of an AF class of a particular LSP, It is possible to evaluate the rate of change in throughput by changing the required bandwidth of the LSP and the magnification of the throughput with respect to other LSPs. As a result, the effect of improving the throughput of the TCP connection of the AF class of the LSP by changing the LSP request band is based on the ratio of the number of TCP flows accommodated in the AF class between the LSPs sharing the congestion AF buffer and the AF minimum of each LSP. The evaluation can be made in consideration of the guaranteed bandwidth.
[0034]
BEST MODE FOR CARRYING OUT THE INVENTION
A traffic monitoring analysis method and system according to an embodiment of the present invention will be described with reference to the drawings.
[0035]
FIG. 1 is a configuration diagram of a packet switching node 15000 including the traffic monitoring device according to the present embodiment. The packet switching node 15000 includes an LSP control unit 15100 that controls an LSP, a packet control unit 15200 that controls a packet, and a traffic monitoring device 15900. The configuration and function of the LSP control unit 15100 are the same as those of the conventional LSP control unit 5100 shown in FIG.
[0036]
The packet control unit 15200 includes input interface processing units 15700, 15701, and 15702 for each input interface, a packet switch unit 15400, and output interface processing units 15800, 15801, and 15802 for each output interface. The functions of the input interface processing units 157000 to 15702 and the packet switch unit 154000 are the same as those of the conventional input interface processing units 5700 to 5703 and the packet switch unit 5600 shown in FIG.
[0037]
FIG. 2 shows a configuration diagram of the output interface processing unit 15800 of the packet switching node 15000. The output interface processing unit 15800 includes a queue selection unit 15810, a packet discard processing unit 15820, an output queue management unit 15830, a scheduling management unit 15840, and a traffic measurement unit 15870 that measures traffic for each LSP. The functions of the queue selection unit 15810, the packet discard processing unit 15820, the output queue management unit 15830, and the scheduling management unit 15840 are respectively performed by the queue selection unit 5810, the packet discard processing unit 5820, and the queue of the conventional output interface processing unit 5800 shown in FIG. Since they are the same as the output queue management unit 5830 and the scheduling management unit 5840, the description is omitted here.
[0038]
The traffic measuring unit 15870 has the traffic information 15879 shown in FIG. The traffic information 15879 includes an output interface identifier 15879-1 for uniquely identifying the packet switching node, an output interface identifier 15879-2 for uniquely identifying the output interface in the packet switching node, and the bandwidth of the link connected to the output interface. , An output link band 15879-3, a traffic measurement date and time 15879-4 which is the date and time when the traffic was measured, and a traffic information table 15871. The traffic information table 15871 includes a measured output label value 15871-2, EF traffic 15871-3, and AF _in Traffic 15871-4 and AF _out It consists of a column of traffic 15871-5.
[0039]
Upon receiving an instruction such as a traffic measurement cycle and a traffic measurement period from the traffic monitoring device 15900, the traffic measurement unit 15870 assigns an output label of a packet input to the output interface processing unit 15800 in the designated traffic measurement period, to the packet. Read the stored EXP value. Then, the traffic measurement date and time is recorded in the column of the traffic measurement date and time 15879-4, and the EF traffic, the AF traffic, and the AF violation traffic per unit time of the EF packet, the AF packet, and the AF violation packet are instructed for each output label value. The measurement is performed at the measurement cycle, and is recorded for each output label value in the column of EF traffic 15871-3, AF traffic 15871-4, and AF violation traffic 15871-5 in the row of output label value 15871-2. Also, when the traffic measurement unit 15870 records the traffic information, if the packet discarding unit 15820 determines that the queue length of the AF buffer exceeds the congestion detection threshold and is in a congested state, the packet switching node identifier 15879- 1. The packet switching node identifier and the output interface identifier are recorded in the column of the output interface identifier 15879-2, and are notified to the traffic monitoring device 15900.
[0040]
The traffic monitoring device 15900 of FIG. 1 accumulates traffic information 15879 notified from the output interface units 15800 to 15802 in the traffic information accumulation unit 15910.
[0041]
The traffic monitoring device 15900 is connected to the management network 30000, and indicates an output interface identifier for performing traffic measurement, a traffic measurement period, and a traffic measurement period from the traffic analysis device 20000 connected to the management network 30000 shown in FIG. Receive. When the traffic monitoring device 15900 receives an instruction from the traffic analysis device 20000, the traffic monitoring device 15900 outputs to the output interfaces 15800 to 15802 having the specified output interface identifier so as to perform the traffic measurement in the specified traffic measurement period and the traffic measurement period. Give instructions. Also, the traffic monitoring device 15900 sends the traffic information stored in the traffic information storage unit 15910 to the traffic analysis device 20000 via the management network 30000 at the timing instructed by the traffic analysis device.
[0042]
FIG. 4 is a configuration diagram of the traffic analysis device according to the present embodiment. As shown in FIG. 4, the traffic analysis device 20000 includes a control unit 20050, an input / output unit 20060, a traffic monitoring unit 22000, a quality prediction unit 23000, a quality analysis unit 24000, a traffic information management unit 25000, It comprises a customer information management unit 26000 and a communication processing control unit 20070, and is connected to the management network 30000.
[0043]
The control unit 20050 controls the input / output unit 20060, the traffic monitoring unit 22000, the quality prediction unit 23000, the quality analysis unit 24000, the traffic information management unit 25000, and the customer information management unit in accordance with the processing request input from the input / output unit 20060. 26000 and the communication processing control unit 20070.
[0044]
The input / output unit 20060 inputs various information from an input device such as a keyboard and outputs various information to an output device such as a display.
[0045]
The traffic monitoring unit 22000 monitors traffic to a desired packet switching node 15000 at a desired arbitrary period (traffic measurement period) for a desired arbitrary output interface at a desired arbitrary period (traffic measurement period). Request to the target packet switching node 15000 via the management network 30000.
[0046]
Based on the traffic information 25110 managed by the traffic information management unit 25000, the quality management unit 24000 shares the congestion AF buffer with the LSP of a particular customer for the throughput of the LSP AF class TCP connection. Then, the multiplication factor of the throughput of the TCP connection of each LSP of another customer is evaluated.
[0047]
Based on the traffic information 25110 managed by the traffic information management unit 25000, the quality prediction unit 23000 calculates the throughput of the AF class TCP connection of the LSP of a specific customer at the time of congestion in which the traffic information 25110 is recorded. Change rate indicating how much the throughput changes when the LSP request bandwidth of the customer is changed. In addition, the quality prediction unit 23000 states, "When the LSP requested bandwidth of the customer is changed, the other LSP of the customer sharing the congestion AF buffer with the LSP of the customer for the throughput of the TCP connection of the AF class of the LSP of the customer. Of the TCP connection throughput of each LSP of the customer.
[0048]
The traffic information management unit 25000 includes a traffic information storage unit 25100 that stores traffic information 25110 sent from a traffic monitoring device in a packet switching node via a network management network. The details of the traffic information 25110 are the same as the traffic information 15879 described in FIG. In the following description, the traffic information 15879 shown in FIG. 3 is used. The traffic information management unit 25000 includes a packet switching node identifier 15879-1, an output interface identifier 15879-2, a traffic measurement date and time 15879-4, and an output label number 15871 from a plurality of pieces of traffic information 15879 stored in the traffic information storage unit 25100. It has a function to search and extract traffic information that matches the logical condition formula created for the -2.
[0049]
The customer information management unit 26000 has a customer information storage unit 26100 that stores customer information 26110. FIG. 5 shows the details of the customer information 26110. The customer information 26110 is created for each LSP set in the MPLS network. The customer ID 26110-1 uniquely identifies a customer who is a user of the LSP, and the LSP contracted between the network operator and the customer. It comprises a required bandwidth 26110-2, an EF maximum guaranteed bandwidth 26110-3 in the LSP, and an LSP route information table 26115. The LSP route information table 26115 includes a packet switching node identifier column 26115-1, an output interface identifier column 26115-2, and an output label value column 26115-3. Each row of the LSP route information table 26115 has an LSP start point. For each packet switch from the packet switching node to the destination packet switching node, the identifier of each packet switching node, the identifier of the interface to which the LSP packet is output in the packet switching node, and the output of the LSP packet from the packet switching node The output label value at that time is recorded in the column 2611-1 of the packet switching node identifier, the column 2611-2 of the output interface identifier, and the column 26115-3 of the output label value in the same row. The customer information management unit 26000 matches the logical condition formula created for the packet switching node identifier, the output interface identifier, the output label value, and the customer ID from the plurality of customer information 26110 stored in the customer information storage unit 26100. It has a function to search for customer information.
[0050]
The communication processing control unit 20070 controls communication processing for communicating with the packet switching node via the management network 30000.
[0051]
The traffic analysis device 20000 according to the present embodiment converts the customer information 26110 stored in the customer information management unit 26000 and the traffic information 25110 stored in the traffic information management unit 25000 (the same structure as the traffic information 15879 in FIG. 3). For the LSP used by a particular customer, the throughput of the AF class TCP connection when the AF buffer congestion is encountered is compared with the throughput of the LSP TCP connection of another customer sharing the AF buffer. A quality analysis process to evaluate is possible. The details of the quality analysis processing will be described below with reference to the quality analysis processing flow of FIG.
[0052]
When the quality analysis processing is started (step S100), a quality analysis processing instruction is input from the input / output unit 20060 together with a customer ID for uniquely identifying a specific customer, and is notified to the control unit 20050 (step S110).
[0053]
Upon receiving the notification, control unit 20050 requests customer information management unit 26000 to search for customer information 26110 that matches the input customer ID. The customer information management unit 26000 that has received the search request responds to the control unit 20050 with all customer information 26110 that matches the customer ID associated with the request (step S120).
[0054]
Upon receiving the response to the customer information 26110, the control unit 20050 requests the traffic information management unit 25000 to search for the traffic information 25110 measured at the output interface of the packet switching node through which the customer's LSP passes, together with the customer information 26110. I do.
[0055]
Upon receiving the traffic information search request, the traffic information management unit 25000 checks the packet switching node identifier and the output interface identifier described in each row of the LSP route information table 26115 of each customer information 26110 received with the search request, for the customer. The output interface of the packet switching node through which the LSP passes is specified, and the traffic information 25100 measured at the output interface is returned to the control unit. Here, at the time of response, in the traffic information table 15871 of the traffic information 25110 (having the same structure as the traffic information 15879 in FIG. 3), it is determined that the row of any output label value relates to the LSP of the customer. For the sake of illustration, it is assumed that the output label is changed to a value that is determined in advance and is not actually possible as a label value (for example, −1). Which line is related to the customer's LSP is determined from the output label described together with the packet switching node identifier and the output interface identifier in each line of the LSP route information table 26115 of each customer information 26110 (step S130). ).
[0056]
The control unit 20050, which has received the response to the traffic information 25110, performs a quality analysis of the TCP connection throughput of the LSP of the customer together with the customer ID input in step S110 for each of the traffic information 25110 which received the response, to the quality analysis unit 24000. To ask.
[0057]
The quality analysis unit 24000 having received the request for the quality analysis performs the above-described step S140 on each of the traffic information 25110 (the same structure as the traffic information 15879 in FIG. 3) from the value of the label value column 15871 of the traffic information table 15871. The row of the label value (−1) indicating the traffic information of the customer's LSP is identified, and the LSP traffic measurement values (EF traffic, AF) recorded in each row of the traffic information table 15871 are identified. _in Traffic, AF _out Traffic) from the customer's LSP (hereinafter LSP) _j ) LSPs of other customers sharing the congestion AF buffer of the output interface with respect to the throughput of the TCP connection _{i (i ≠ j)} ) TCP connection throughput ratio r _{i (i ≠ j)} Is calculated (step S140).
[0058]
In this step S140, the quality analysis unit 24000 extracts the LSP of a specific customer from the traffic information 25110 (the same structure as the traffic information 15879 in FIG. 3). _j Other LSPs sharing the congestion AF buffer of the output interface with respect to the TCP connection throughput _{i (i ≠ j)} Of TCP connection throughput r _{i (i ≠ j)} The method of calculating is shown below.
[0059]
Each row of the traffic information table 15871 in the traffic information 15879 includes, at the output interface of the packet switching node identified by the packet switching node identifier 15789-1 and the output interface identifier 15879-2, the traffic measurement unit 15870 when the AF buffer is congested. Output label value and traffic information (EF traffic, AF _in Traffic, AF _out Traffic) is recorded in each row 1587-1-21587-1-5 of each row. The traffic information on the i-th row from the traffic information table 15871 is LSP _i LSP _i EF traffic 15871-3, AF _in Traffic 15871-4, AF _out Traffic 15871-5 is assigned to e _i , A _i , B _i And It is assumed that a label value (−1) indicating the LSP of the specific customer is added to the output label information on the j-th line from the top of the traffic information table 15871. LSP of said specific customer is LSP _j LSP _j EF traffic 15871-3, AF _in Traffic 15871-4, AF _out Traffic 15871-5 is assigned to e _j , A _j , B _j And
[0060]
In general, the throughput of a TCP connection is inversely proportional to the square root of the packet drop probability (see Non-Patent Document 11). _out Assuming that the packet drop probability applied to the packet is ρ, the specific customer LSP _j LSP of other customers against the throughput of TCP connection of _{i (i ≠ j)} Of TCP connection throughput r _{i (i ≠ j)} Is represented by the following equation.
[0061]
(Equation 4)

[0062]
LSP of specific customer in traffic information table 15871 _j For each row other than the j-th row, the specific customer LSP is calculated using Expression (1). _j LSP of other customers against the throughput of TCP connection of _{i (i ≠ j)} Of TCP connection throughput r _{i (i ≠ j)} To evaluate. Magnification r _{i (i ≠ j)} Indicates that, as the value becomes larger than 1, the effect of congestion on the decrease in the throughput of the TCP connection of the LSP of the specific customer due to congestion is greater than that of other LSPs.
[0063]
LSP of a specific customer (hereinafter LSP) _j ) Each LSP of other customers sharing the congestion AF buffer of the output interface for the throughput of the TCP connection _{i (i ≠ j)} Of TCP connection throughput r _{i (i ≠ j)} Is greater than a predetermined threshold value, that is, when it is determined that the influence of a decrease in the TCP connection throughput of the LSP of the customer due to congestion is greater than that of another customer's LSP. , The quality analysis unit 24000 calculates the customer ID, the magnification r _{i (i ≠ j)} And the traffic information 25110 is temporarily stored in the analysis result storage unit 24500 (step S150). For all the traffic information 25110 requested by the control unit 20050, the quality analysis unit 24000 that has completed the quality analysis processing shown in steps S140 and S150 notifies the control unit 20050 of the end of the quality analysis processing. The control unit 20050 that has received the notification of the end of the quality analysis processing ends the processing (step S160). The above is the description of the quality analysis processing flow of the present invention shown in FIG.
[0064]
The traffic analysis device 20000 of the present invention is determined by the quality analysis processing flow described above with reference to FIG. 6 to have a large influence on the decrease in the throughput of the TCP connection of the LSP of the specific customer, and accumulates it in the quality analysis result storage unit 24500. Selected traffic information, and the LSP of the specific customer recorded in the traffic information table 15871. _j Is changed to an arbitrary value, the EF traffic 1587-1-3, which is the traffic measurement value of each LSP recorded in each row of the traffic information table 15871, _in Traffic 15871-4, AF _out The changed value of the traffic 15871-5 is predicted, and the LSP of the customer before the change is predicted. _j Customer LSP after changing TCP connection throughput _j Of the TCP_throughput rate of change Rate_myself, and the LSP of the customer after the change _j LSPs of other customers against TCP connection throughput _{i (i ≠ j)} TCP connection throughput r ' _{i (i ≠ j)} Quality prediction processing for making predictions. The details of the quality prediction processing will be described with reference to the quality prediction processing flow of FIG.
[0065]
When the quality prediction processing is started (step S200), a quality prediction processing command is input to the input / output unit 20060 from an input device such as a keyboard, and is notified to the control unit 20050 (step S210).
[0066]
Upon receiving the notification, the control unit 20050 sends the quality analysis unit 24000 the accumulated information in the analysis result storage unit 24500 (each traffic information, the TCP connection of the LSP of another customer to the TCP connection throughput of the LSP of another customer in each traffic information). Request to display a list of connection throughput ratio and customer ID).
[0067]
Upon receiving the request, the quality analysis unit 24000 outputs the accumulated information in the analysis result storage unit 24500 to the input / output unit 20060, and then notifies the control unit 20050 of the end of the list display together with the customer ID (step S220).
[0068]
Upon receiving the customer ID and the list display end notification, control unit 20050 outputs to input / output unit 20060 a message prompting input / output unit 20060 to select traffic information 15879. The input / output unit 20060, which receives the packet switching node identifier, the output interface identifier, and the traffic measurement date input from an input device such as a keyboard in order to uniquely select the traffic information 15879, notifies the control unit 20050 of the input information. .
[0069]
Upon receiving the input information, the control unit 20050 notifies the quality analysis unit 24000 of the packet switching node identifier, the output interface identifier, and the traffic measurement date, which are the input information.
[0070]
Upon receiving the input information, the quality analysis unit 24000 transfers the traffic information 15879 having the same packet switching node identifier, output interface identifier, and traffic measurement date according to the input information to the quality prediction unit 23000 and notifies the control unit 20050 ( Step S230).
[0071]
The control unit 20050 having received the notification obtains the customer ID received from the analysis result temporary storage unit 24500 in the step S220 in order to obtain the required bandwidth value of the customer's LSP in the traffic information 15879 selected in the step S230. The LSP request bandwidth search request of the customer is transmitted to the customer information management unit 26000 together with the packet switching node identifier, the output interface identifier, and the traffic measurement date received in step S230.
[0072]
Upon receiving the LSP request band search request for the customer, the customer information management unit 26000 matches the customer ID from the customer information 26110 stored in the customer information storage unit 26100, and stores the packet switching node in the LSP route information table 26115. The customer information 26110 including the line where the identifier and the output interface identifier match is searched, and the value of the LSP required bandwidth value 26110-2 is returned to the control unit 20050.
[0073]
Upon receiving the response, the control unit 20050 inputs and outputs the LSP requested bandwidth value and the LSP requested bandwidth correction value input permission message to an external output device such as a display. Command to. In accordance with the instruction, the input / output unit 20060 outputs the LSP requested bandwidth value of the customer and the LSP requested bandwidth correction value input permission message to an external output device such as a display (step S240).
[0074]
When the required bandwidth correction value Z of the LSP is input from an input device such as a keyboard to the input / output unit 20060 (step S250), the input required bandwidth correction value Z of the LSP is notified to the control unit 20050.
[0075]
The control unit 20050 receiving the LSP requested band correction value Z requests the quality prediction unit 23000 to perform a quality prediction process together with the LSP requested band correction value Z. The quality predicting unit 23000 receiving the request changes the required bandwidth of the customer's LSP recorded in the traffic information table 15871 of the traffic information 15879 received from the quality analyzing unit 24000 to the required bandwidth correction value Z. LSP EF traffic, AF _in Traffic, AF _out The EF traffic 15871-3, which is the traffic measurement value of each LSP recorded in each row of the traffic information table, _in Traffic 15871-4, AF _out The prediction is performed as follows using the value of the traffic 15871-5 (step S260).
[0076]
[EF traffic and AF of each LSP after modification of required bandwidth of customer LSP _in Traffic, AF _out Traffic prediction method]
Each row of the traffic information table 25871 in the traffic information 15879 has an output interface having the identifier of the output interface of the packet switching node having a certain packet switching node identifier, and is measured by the traffic measuring unit 15870 shown in FIG. The traffic information for each LSP is recorded, and the output label value of the LSP and the traffic information (EF traffic, AF _in Traffic, AF _out Traffic) is recorded in each column of each row. It is assumed that a label value (−1) indicating the LSP of a specific customer is assigned to the output label information on the j-th line from the top of the traffic information table 15871. The traffic information on the i-th row from the traffic information table 15871 is LSP _{i (i ≠ j)} LSP _i EF traffic 15871-3, AF _in Traffic 15871-4, AF _out Traffic 15871-5 to e _i , A _i , B _i And the value obtained when the value is corrected to the required band correction value Z of the LSP of the specific customer is e ′. _i , A ' _i , B ' _i And LSP of said specific customer is LSP _j LSP _j EF traffic 15871-3, AF _in Traffic 15871-4, AF _out Traffic 15871-5 to e _j , A _j , B _j And the value obtained by modifying the required bandwidth modification value Z of the customer's LSP to e ′ _j , A ' _j , B ' _j And
[0077]
[EF traffic, AF _in Traffic Estimation]
LSP _j , LSP _{i (i ≠ j)} EF traffic is the customer's LSP _j Is not affected by the required bandwidth correction value Z of _i , E ' _j Is estimated as follows.
[0078]
(Equation 5)

[0079]
LSP of the customer after changing to the requested bandwidth correction value Z _j AF _in Traffic a ' _j Is estimated as follows.
[0080]
(Equation 6)

[0081]
LSP of other customers _{i (i ≠ j)} AF _in Traffic a ' _{i (i ≠ j)} Is not affected by the required bandwidth modification value Z of the customer's LSP, it is estimated as follows.
[0082]
(Equation 7)

[0083]
[AF _out Traffic Estimation]
K that satisfies the following equation (5) is obtained using the binary search method, and further, using the obtained K, the LSP of the specific customer is obtained. _j AF _out Traffic b ' _j , LSP of other customers _{i (i ≠ j)} AF _out Traffic b ' _i Is estimated by equations (6) and (7).
[0084]
(Equation 8)

[0085]
The method of deriving the above equations (5) to (7) will be described below.
[0086]
[Method of Deriving Equations (5) to (7)]
LSP of specific customer _j LSP of other customers for _{i (i ≠ j)} AF class TCP flow number ratio f _i Is not changed by the change of the bandwidth requested by the customer, and is expressed as follows (see Non-Patent Document 10).
[0087]
(Equation 9)

[0088]
(F _i ) ² = F _i Then, equation (7) becomes
[0089]
(Equation 10)

[0090]
It is expressed as Assuming K (≧ 0) that satisfies the following equation (9),
[0091]
(Equation 11)

[0092]
From Expressions (9) and (10), they are expressed as follows.
[0093]
(Equation 12)

[0094]
Equation (10) is expressed as b ′ _i Solving for b ' _i > 0, b ′ _i Is expressed as follows.
[0095]
(Equation 13)

[0096]
Equation (11) is replaced by b ′ _j Solving for b ' _j > 0, b ′ _j Is expressed as follows.
[0097]
[Equation 14]

[0098]
AF of each LSP _out The total traffic is calculated from the value (C) of the output link band 15879-4 in the traffic information 15879 by the AF of each LSP. _in Since the value is equal to a value obtained by subtracting the total value of the traffic and the EF traffic, the value is expressed as follows.
[0099]
(Equation 15)

[0100]
Also, from equations (12), (13) and (14)
[0101]
(Equation 16)

[0102]
That is,
[0103]
[Equation 17]

[0104]
It becomes. here,
[0105]
(Equation 18)

[0106]
Therefore, substituting equation (17) into equation (16) gives
[0107]
[Equation 19]

[0108]
It becomes.
[0109]
Next, it is shown below that when equation (18) is an equation for K (≧ 0), there is always one solution. The left side of equation (18) is a monotonically increasing function for K. When K = 0, the minimum value is
[0110]
(Equation 20)

[0111]
It becomes. Minimum value from right to left of equation (18)
[0112]
(Equation 21)

[0113]
When subtracted, it is expressed as follows.
[0114]
(Equation 22)

[0115]
here,
[0116]
[Equation 23]

[0117]
Is the sum of the required bandwidths of each LSP, and should be equal to or less than the link bandwidth C.
[0118]
(Equation 24)

[0119]
Is greater than or equal to 0, and the right side of equation (18) ≧ the minimum value of the left side of equation (18). Therefore, it is understood that there is always one K (≧ 0) that satisfies Expression (18).
[0120]
It can be seen from equation (18) that the solution K in equation (18) satisfies the following inequality (19).
[0121]
(Equation 25)

[0122]
Therefore, K that satisfies Expression (18) can be obtained using the binary search method in a range that satisfies Inequality (19). Equations (5) to (7) can be derived from the above.
[0123]
The quality prediction process will be described again with reference to FIG. LSP of specific customer _j LSP of the customer after changing the required bandwidth to the required bandwidth correction value Z _j And LSPs of other customers _{i (i ≠ j)} EF traffic e ' _j , E ' _i , AF _in Traffic a ' _j , A ' _i , AF _out Traffic b ' _j , B ' _i The quality prediction unit 23000 that has predicted the value is the LSP of the customer. _j The rate of change of the throughput per TCP connection of the customer's LSP after the required bandwidth modification of the TCP connection per TCP connection before the required bandwidth modification is calculated using the following equation (20) (step S270). .
[0124]
(Equation 26)

[0125]
The method of deriving the above equation (20) will be described below.
[0126]
When the AF buffer is congested, the packet drop probability ρ applied by the RIO is defined as the LSP of the customer recorded in the traffic information table measured during the congestion. _j AF _in Traffic a _j , AF _out Traffic b _j To LSP _j Of one TCP connection of avr _j Is expressed as follows.
[0127]
[Equation 27]

[0128]
On the other hand, the LSP of the customer estimated in step S260 _j AF after LSP request band correction _in Traffic a ' _j , AF _out Traffic b ' _j From the LSP _j Of one TCP connection of avr ' _j Is expressed as follows.
[0129]
[Equation 28]

[0130]
Therefore, the throughput change ratio Ratio_myself is represented by avr expressed by Expression (21). _j Avr ′ represented by equation (22) for _j And expressed as in equation (20).
[0131]
LSP of the customer _j The quality prediction unit 23000 that has completed the calculation of the ratio of the throughput per TCP connection Ratio_myself after the required bandwidth modification of the LSP of the customer, _j LSP of customer after required bandwidth modification _j LSP of other customers against the throughput of TCP connection of _{i (i ≠ j)} TCP connection throughput r ' _{i (i ≠ j)} Is obtained by using the following equation (23) as in the case of equation (1) (step S280).
[0132]
(Equation 29)

[0133]
TCP connection throughput change ratio Ratio_myself, TCP connection throughput magnification r ' _i The quality estimating unit that has obtained the “Ratio_myself, r ′” to the control unit 20050. _i Responds with the value of Upon receiving the response, the control unit 20050 checks the Ratio_myself, r ′ _i Is input to the input / output unit 20060 to output the value to an external output device such as a display. The input / output unit 20060 responds to the instruction by using the Ratio_myself, r ′ _i Is output to an external output device such as a display, and the quality prediction process ends (step S290).
[0134]
【The invention's effect】
As described in detail above, according to the present invention, when congestion occurs in the output AF buffer, the ratio of the throughput of the TCP connection of the AF class of another LSP to the throughput of the TCP connection of the AF class of the specific LSP , And the throughput change rate by changing the required bandwidth of a specific LSP and the magnification of the throughput with respect to other LSPs can be evaluated. As a result, the effect of improving the throughput of the TCP connection of the AF class of the LSP by changing the LSP request band is based on the ratio of the number of TCP flows accommodated in the AF class between the LSPs sharing the congestion AF buffer and the AF minimum of each LSP. The evaluation can be made in consideration of the guaranteed bandwidth.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a traffic monitoring and analysis system.
FIG. 2 is a configuration diagram of an output interface processing unit of the packet switching node;
FIG. 3 illustrates an example of a data structure of traffic information.
FIG. 4 is a configuration diagram of a traffic analysis device.
FIG. 5 illustrates an example of a data structure of customer information.
FIG. 6 is a flowchart illustrating quality analysis processing.
FIG. 7 is a flowchart illustrating quality prediction processing.
FIG. 8 is a configuration diagram of an MPLS network.
FIG. 9 is a graph showing the packet drop probability due to RIO.
FIG. 10 is a configuration diagram of a conventional packet switching node.
FIG. 11 is a configuration diagram of an output interface processing unit of a conventional packet switching node.
[Explanation of symbols]
15000: Packet switching node, 15100: LSP control unit, 15300: Resource information management unit, 15400: LSP information management unit, 15500 LSP control message processing unit, 15200: Packet control unit, 15700 to 15702: Input interface processing unit, 15800 to 15802 ... output interface processing unit, 15810 ... queue selection unit, 15820 ... packet discard processing unit, 15830 ... output queue management unit, 15840 ... scheduling management unit, 15870 ... traffic measurement unit, 15600 ... packet switch unit, 15900 ... traffic monitoring device, 15910: traffic information storage unit, 20000: traffic analysis device, 20050: control unit, 20006: input / output unit, 20070: communication processing control unit, 22000: traffic monitoring , 23000: quality prediction unit, 24000: quality analysis unit, 24500: analysis result storage unit, 25000: traffic information management unit, 25100: traffic information storage unit, 26000: customer information management unit, 26100: customer information storage unit, 30,000 ... Management network

Claims (5)

A traffic monitoring and analysis method in an MPLS (Multi-Protocol Label Switching) network that supports Diffserv (Differentiated Services),
Each packet switching node in the MPLS network periodically measures traffic at each output interface at each LSP (Label Switched Path),
A traffic monitoring / analyzing device that connects to each packet switching node via a predetermined management network,
Receiving the traffic information from each packet switching node and storing it in traffic information storage means,
When the output AF buffer of the output interface of each packet switching node is congested, traffic information recorded for a specific LSP _j is used using traffic information for all (i) LSPs sharing the output AF buffer. From the traffic information accumulating means, and the ratio r _i of the throughput of the TCP connection of the other LSP _{i (i ≠ j)} sharing the output AF buffer to the throughput of the TCP connection of the LSP _j included in the traffic information. Perform quality analysis processing to analyze _{(i ≠ j)} ,
Extracting the traffic information determined by the quality analysis processing that the influence of the decrease in the throughput of the TCP connection of the specific LSP _j at the time of congestion is larger than that of the other LSP _{i (i ≠ j)} ;
Using the extracted traffic information, when the required bandwidth of the specific LSP _j is changed to a desired value, the rate of change in the throughput of the TCP connection of the specific LSP _j after the change before the change, Ratio_myself, and after the change A traffic prediction analysis method for performing a quality prediction process of predicting a magnification r _{i (i ≠ j)} of a throughput of a TCP connection of another LSP _i with respect to a throughput of a TCP connection of a specific LSP _{j in} the above. The traffic information includes an AF _in traffic rate a _i that is a traffic rate of an AF packet that is marked to indicate that the total inflow rate of the AF class / EF class exceeds the LSP request band, and an AF that is not marked. and a _{AF out} traffic rate _{b i} is the traffic rate of the packets,
In the quality analysis processing, the magnification r _{i (i ≠ j)} is calculated by the following equation.

2. The traffic monitoring and analyzing method according to claim 1, wherein: The traffic information includes an EF traffic rate e _i , an AF _in traffic rate a _i that is a traffic rate of an AF packet marked to indicate that the total inflow rate of the AF class / EF class has exceeded the LSP request band, and a _{AF out} traffic rate _{b i} is the traffic rate of AF packets which the marking has not been performed,
In the quality prediction process, when the required band of the specific LSP _j is changed to the band Z, the traffic information (AF _in traffic rate a ′ _i and AF _out traffic rate b ′ _i ) of the specific LSP _j after the change, and , And other LSP _j traffic information (AF _in traffic rate a ′ _{i (i （j)} and AF _out traffic rate b ′ _{i (i ≠ j)} ) are calculated by the following equation.

2. The traffic monitoring and analyzing method according to claim 1, wherein: 4. The traffic monitoring analysis method according to claim 3, wherein in the quality prediction processing, the Ratio_myself and the scaling factor ri _{(i （j)} are calculated by the following equation.

A traffic monitoring and analysis system in an MPLS (Multi-Protocol Label Switching) network that supports Diffserv (Differentiated Services),
Each packet switching node in the MPLS network includes traffic measuring means for periodically measuring traffic at each output interface for each LSP (Label Switched Path),
Traffic information management means for receiving the traffic information from each packet switching node via a predetermined management network and storing the traffic information in traffic information storage means;
When the output AF buffer of the output interface of each packet switching node is congested, traffic information recorded for a specific LSP _j is used using traffic information for all (i) LSPs sharing the output AF buffer. From the traffic information accumulating means, and the ratio r _i of the throughput of the TCP connection of the other LSP _{i (i ≠ j)} sharing the output AF buffer to the throughput of the TCP connection of the LSP _j included in the traffic information. Quality analysis means for analyzing _{(i ≠ j)} ;
Means for extracting traffic information determined by the quality analysis processing that the influence of the decrease in the throughput of the TCP connection of the specific LSP _j at the time of congestion is greater than that of the other LSP _{i (i ≠ j)} ;
Using the extracted traffic information, when the required bandwidth of the specific LSP _j is changed to a desired value, the rate of change in the throughput of the TCP connection of the specific LSP _j after the change before the change, Ratio_myself, and after the change A traffic monitoring / analyzing device having a quality prediction means for predicting a magnification r _{i (i ≠ j)} of a throughput of a TCP connection of another LSP _i with respect to a throughput of a TCP connection of a specific LSP _{j in} the above. Monitoring and analysis system.

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