Internet Engineering Task Force (IETF)                          A. Clark
Request for Comments: 6390                         Telchemy Incorporated
BCP: 170                                                       B. Claise
Category: Best Current Practice                      Cisco Systems, Inc.
ISSN: 2070-1721                                             October 2011
     Guidelines for Considering New Performance Metric Development



This document describes a framework and a process for developing Performance Metrics of protocols and applications transported over IETF-specified protocols. These metrics can be used to characterize traffic on live networks and services.


Status of This Memo


This memo documents an Internet Best Current Practice.


This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on BCPs is available in Section 2 of RFC 5741.

このドキュメントはインターネットエンジニアリングタスクフォース(IETF)の製品です。これは、IETFコミュニティの総意を表しています。これは、公開レビューを受けており、インターネットエンジニアリング運営グループ(IESG)によって公表のために承認されています。 BCPの詳細については、RFC 5741のセクション2で利用可能です。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved.

著作権(C)2011 IETF信託とドキュメントの作成者として特定の人物。全著作権所有。

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

この文書では、BCP 78と、この文書の発行日に有効なIETFドキュメント(に関連IETFトラストの法律の規定に従うものとします。彼らは、この文書に関してあなたの権利と制限を説明するように、慎重にこれらの文書を確認してください。コードコンポーネントは、トラスト法規定のセクションで説明4.eおよび簡体BSDライセンスで説明したように、保証なしで提供されているよう簡体BSDライセンスのテキストを含める必要があり、この文書から抽出されました。

This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English.


Table of Contents


   1. Introduction ....................................................4
      1.1. Background and Motivation ..................................4
      1.2. Organization of This Document ..............................5
   2. Terminology .....................................................5
      2.1. Requirements Language ......................................5
      2.2. Performance Metrics Directorate ............................5
      2.3. Quality of Service .........................................5
      2.4. Quality of Experience ......................................6
      2.5. Performance Metric .........................................6
   3. Purpose and Scope ...............................................6
   4. Relationship between QoS, QoE, and Application-Specific
      Performance Metrics .............................................7
   5. Performance Metrics Development .................................7
      5.1. Identifying and Categorizing the Audience ..................7
      5.2. Definitions of a Performance Metric ........................8
      5.3. Computed Performance Metrics ...............................9
           5.3.1. Composed Performance Metrics ........................9
           5.3.2. Index ..............................................10
      5.4. Performance Metric Specification ..........................10
           5.4.1. Outline ............................................10
           5.4.2. Normative Parts of Performance Metric Definition ...11
           5.4.3. Informative Parts of Performance Metric
                  Definition .........................................13
           5.4.4. Performance Metric Definition Template .............14
           5.4.5. Example: Loss Rate .................................15
      5.5. Dependencies ..............................................16
           5.5.1. Timing Accuracy ....................................16
           5.5.2. Dependencies of Performance Metric Definitions on
                  Related Events or Metrics ..........................16
           5.5.3. Relationship between Performance Metric and
                  Lower-Layer Performance Metrics ....................17
           5.5.4. Middlebox Presence .................................17
      5.6. Organization of Results ...................................17
      5.7. Parameters: The Variables of a Performance Metric .........18
   6. Performance Metric Development Process .........................18
      6.1. New Proposals for Performance Metrics .....................18
      6.2. Reviewing Metrics .........................................19
      6.3. Performance Metrics Directorate Interaction with
           Other WGs .................................................19
      6.4. Standards Track Performance Metrics .......................20
   7. Security Considerations ........................................20
   8. Acknowledgements ...............................................20
   9. References .....................................................21
      9.1. Normative References ......................................21
      9.2. Informative References ....................................21
1. Introduction
1. はじめに

Many networking technologies, applications, or services are distributed in nature, and their performance may be impacted by IP impairments, server capacity, congestion, and other factors. It is important to measure the performance of applications and services to ensure that quality objectives are being met and to support problem diagnosis. Standardized metrics help ensure that performance measurement is implemented consistently, and they facilitate interpretation and comparison.


There are at least three phases in the development of performance standards. They are as follows:


1. Definition of a Performance Metric and its units of measure
2. Specification of a method of measurement
3. Specification of the reporting format

During the development of metrics, it is often useful to define performance objectives and expected value ranges. This additional information is typically not part of the formal specification of the metric but does provide useful background for implementers and users of the metric.


The intended audience for this document includes, but is not limited to, IETF participants who write Performance Metrics documents in the IETF, reviewers of such documents, and members of the Performance Metrics Directorate.


1.1. Background and Motivation
1.1. 背景と動機

Previous IETF work related to the reporting of application Performance Metrics includes "Real-time Application Quality-of-Service Monitoring (RAQMON) Framework" [RFC4710]. This framework extends the remote network monitoring (RMON) family of specifications to allow real-time quality-of-service (QoS) monitoring of various applications that run on devices such as IP phones, pagers, Instant Messaging clients, mobile phones, and various other handheld computing devices. Furthermore, "RTP Control Protocol Extended Reports (RTCP XR)" [RFC3611] and "Session Initiation Protocol Event Package for Voice Quality Reporting" [RFC6035] define protocols that support real-time Quality of Experience (QoE) reporting for Voice over IP (VoIP) and other applications running on devices such as IP phones and mobile handsets.

アプリケーションのパフォーマンス・メトリックの報告に係る前IETFの仕事は、「リアルタイムアプリケーションサービス品質のモニタリング(RAQMON)フレームワーク」[RFC4710]を含んでいます。このフレームワークは、リモートネットワークモニタリング(RMON)、IP電話、ポケットベル、インスタントメッセージングクライアント、携帯電話などのデバイス上で動作する様々なアプリケーションのリアルタイムのサービス品質(QoS)の監視を可能にする仕様の家族、そして様々なを拡張します他のハンドヘルドコンピューティングデバイス。さらに、[RFC6035]は経験のリアルタイムの品質ボイスオーバーIP用(ユーザ体感品質)の報告を(サポートするプロトコルを定義する「音声品質を報告するためのセッション開始プロトコルイベントパッケージ」[RFC3611]と「RTP制御プロトコルは、レポート(RTCP XR)の拡張しました」 VoIPの)と、IP電話や携帯電話などのデバイス上で実行されている他のアプリケーション。

The IETF is also actively involved in the development of reliable transport protocols, such as TCP [RFC0793] or the Stream Control Transmission Protocol (SCTP) [RFC4960], which would affect the relationship between IP performance and application performance.


Thus, there is a gap in the currently chartered coverage of IETF Working Groups (WGs): development of Performance Metrics for protocols above and below the IP layer that can be used to characterize performance on live networks.


Similar to "Guidelines for Considering Operations and Management of New Protocols and Protocol Extensions" [RFC5706], which is the reference document for the IETF Operations Directorate, this document should be consulted as part of the new Performance Metric review by the members of the Performance Metrics Directorate.


1.2. Organization of This Document
1.2. この書類の構成

This document is divided into two major sections beyond the "Purpose and Scope" section. The first is a definition and description of a Performance Metric and its key aspects. The second defines a process to develop these metrics that is applicable to the IETF environment.


2. Terminology
2.1. Requirements Language
2.1. 要件言語

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].

この文書のキーワード "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", および "OPTIONAL" はRFC 2119 [RFC2119]に記載されているように解釈されます。

2.2. Performance Metrics Directorate
2.2. パフォーマンス・メトリック総局

The Performance Metrics Directorate is a directorate that provides guidance for Performance Metrics development in the IETF.


The Performance Metrics Directorate should be composed of experts in the performance community, potentially selected from the IP Performance Metrics (IPPM), Benchmarking Methodology (BMWG), and Performance Metrics for Other Layers (PMOL) WGs.


2.3. Quality of Service
2.3. サービスの質

Quality of Service (QoS) is defined in a way similar to the ITU "Quality of Service (QoS)" section of [E.800], i.e., "Totality of characteristics of a telecommunications service that bear on its ability to satisfy stated and implied needs of the user of the service".


2.4. Quality of Experience
2.4. 体感品質

Quality of Experience (QoE) is defined in a way similar to the ITU "QoS experienced/perceived by customer/user (QoSE)" section of [E.800], i.e., "a statement expressing the level of quality that customers/users believe they have experienced".

体感品質(QoEのは)[E.800]のセクション、すなわち、「品質のレベルを表現する声明ITU「顧客/ユーザー(QoSE)によって知覚経験のQoS /」に似た方法で定義された顧客/ユーザー」彼らが経験してきたと信じています。

NOTE 1 - The level of QoS experienced and/or perceived by the customer/user may be expressed by an opinion rating.

注1 - 顧客/ユーザーが経験および/または認知のQoSのレベルは意見の評価で表すことができます。

NOTE 2 - QoE has two main components: quantitative and qualitative. The quantitative component can be influenced by the complete end-to-end system effects (including user devices and network infrastructure).

注2 - のQoEは2つの主要コンポーネントがあります:定量的および定性的に。定量的な成分は、(ユーザ装置とネットワークインフラストラクチャを含む)完全なエンドツーエンドのシステムの影響によって影響され得ます。

NOTE 3 - The qualitative component can be influenced by user expectations, ambient conditions, psychological factors, application context, etc.

注3 - 質的コンポーネントは、ユーザの期待、周囲条件、心理的要因、アプリケーションコンテキスト、等によって影響され得ます

NOTE 4 - QoE may also be considered as QoS delivered, received, and interpreted by a user with the pertinent qualitative factors influencing his/her perception of the service.

注4 - たQoEはまた、配信のQoSとして受信考えられ、サービスの彼/彼女の知覚に影響を与える適切な定性的要因でユーザによって解釈されてもよいです。

2.5. Performance Metric
2.5. パフォーマンスメトリック

A Performance Metric is a quantitative measure of performance, specific to an IETF-specified protocol or specific to an application transported over an IETF-specified protocol. Examples of Performance Metrics are the FTP response time for a complete file download, the DNS response time to resolve the IP address, a database logging time, etc.


3. Purpose and Scope

The purpose of this document is to define a framework and a process for developing Performance Metrics for protocols above and below the IP layer (such as IP-based applications that operate over reliable or datagram transport protocols). These metrics can be used to characterize traffic on live networks and services. As such, this document does not define any Performance Metrics.


The scope of this document covers guidelines for the Performance Metrics Directorate members for considering new Performance Metrics and suggests how the Performance Metrics Directorate will interact with the rest of the IETF. However, this document is not intended to supersede existing working methods within WGs that have existing chartered work in this area.


This process is not intended to govern Performance Metric development in existing IETF WGs that are focused on metrics development, such as the IPPM and BMWG WGs. However, this guidelines document may be useful in these activities and MAY be applied where appropriate. A typical example is the development of Performance Metrics to be exported with the IP Flow Information eXport (IPFIX) protocol [RFC5101], with specific IPFIX information elements [RFC5102], which would benefit from the framework in this document.


The framework in this document applies to Performance Metrics derived from both active and passive measurements.


4. Relationship between QoS, QoE, and Application-Specific Performance Metrics


Network QoS deals with network and network protocol performance, while QoE deals with the assessment of a user's experience in the context of a task or a service. The topic of application-specific Performance Metrics includes the measurement of performance at layers between IP and the user. For example, network QoS metrics (packet loss, delay, and delay variation [RFC5481]) can be used to estimate application-specific Performance Metrics (de-jitter buffer size and RTP-layer packet loss), and then combined with other known aspects of a VoIP application (such as codec type) using an algorithm compliant with ITU-T P.564 [P.564] to estimate a Mean Opinion Score (MOS) [P.800]. However, the QoE for a particular VoIP user depends on the specific context, such as a casual conversation, a business conference call, or an emergency call. Finally, QoS and application-specific Performance Metrics are quantitative, while QoE is qualitative. Also, network QoS and application-specific Performance Metrics can be directly or indirectly evident to the user, while the QoE is directly evident.

ユーザ体感品質は、タスクやサービスのコンテキストにおけるユーザの経験の評価を扱っている間、ネットワークQoSは、ネットワークおよびネットワークプロトコルのパフォーマンスを扱っています。アプリケーション固有のパフォーマンス・メトリックのトピックは、IPとユーザとの間の層での性能の測定を含みます。例えば、ネットワークのQoSメトリック(パケットロス、遅延、および遅延変動[RFC5481])他の公知の態様で、アプリケーション固有のパフォーマンス・メトリック(デジッタバッファサイズとRTP層パケット損失)を推定するために使用した後に組み合わせることができます準拠したアルゴリズムを使用して(例えばコーデックタイプなど)VoIPアプリケーションのITU-T P.564 [P.564]平均オピニオンスコア(MOS)[P.800]を推定します。しかし、特定のVoIPユーザーのQoEは、カジュアルな会話、ビジネス、会議通話、または緊急呼び出しなど、特定のコンテキストに依存します。ユーザ体感品質が定性的である一方、最後に、QoSおよびアプリケーション固有のパフォーマンス・メトリックは、定量的です。ユーザ体感品質を直接明らかであるが、また、ネットワークのQoSおよびアプリケーション固有のパフォーマンス・メトリックは、ユーザに直接または間接的に明らかであることができます。

5. Performance Metrics Development

This section provides key definitions and qualifications of Performance Metrics.


5.1. Identifying and Categorizing the Audience
5.1. 対象読者を識別し、分類します

Many of the aspects of metric definition and reporting, even the selection or determination of the essential metrics, depend on who will use the results, and for what purpose. For example, the metric description SHOULD include use cases and example reports that illustrate service quality monitoring and maintenance or identification and quantification of problems.


All documents defining Performance Metrics SHOULD identify the primary audience and its associated requirements. The audience can influence both the definition of metrics and the methods of measurement.


The key areas of variation between different metric users include:


o Suitability of passive measurements of live traffic or active measurements using dedicated traffic


o Measurement in laboratory environment or on a network of deployed devices


o Accuracy of the results


o Access to measurement points and configuration information


o Measurement topology (point-to-point, point-to-multipoint)


o Scale of the measurement system


o Measurements conducted on-demand or continuously


o Required reporting formats and periods


o Sampling criteria [RFC5474], such as systematic or probabilistic


o Period (and duration) of measurement, as the live traffic can have patterns


5.2. Definitions of a Performance Metric
5.2. パフォーマンスメトリックの定義

A Performance Metric is a measure of an observable behavior of a networking technology, an application, or a service. Most of the time, the Performance Metric can be directly measured; however, sometimes, the Performance Metric value is computed. The process for determining the value of a metric may assume an implicit or explicit underlying statistical process; in this case, the Performance Metric is an estimate of a parameter of this process, assuming that the statistical process closely models the behavior of the system.


A Performance Metric should serve some defined purposes. This may include the measurement of capacity, quantifying how bad some problems are, measurement of service level, problem diagnosis or location, and other such uses. A Performance Metric may also be an input to some other processes, for example, the computation of a composite Performance Metric or a model or simulation of a system. Tests of the "usefulness" of a Performance Metric include:


(i) the degree to which its absence would cause significant loss of information on the behavior or performance of the application or system being measured


(ii) the correlation between the Performance Metric, the QoS, and the QoE delivered to the user (person or other application)


(iii) the degree to which the Performance Metric is able to support the identification and location of problems affecting service quality


(iv) the requirement to develop policies (Service Level Agreement, and potentially Service Level Contract) based on the Performance Metric


For example, consider a distributed application operating over a network connection that is subject to packet loss. A Packet Loss Rate (PLR) Performance Metric is defined as the mean packet loss ratio over some time period. If the application performs poorly over network connections with a high packet loss ratio and always performs well when the packet loss ratio is zero, then the PLR Performance Metric is useful to some degree. Some applications are sensitive to short periods of high loss (bursty loss) and are relatively insensitive to isolated packet loss events; for this type of application, there would be very weak correlation between PLR and application performance. A "better" Performance Metric would consider both the packet loss ratio and the distribution of loss events. If application performance is degraded when the PLR exceeds some rate, then a useful Performance Metric may be a measure of the duration and frequency of periods during which the PLR exceeds that rate (as, for example, in RFC 3611).

例えば、パケット損失を受けるネットワーク接続上で動作する分散アプリケーションを考えます。パケット損失率(PLR)のパフォーマンスメトリックは、ある程度の時間をかけて平均パケット損失率と定義されます。アプリケーションが高いパケット損失率とのネットワーク接続を介して悪い行いやパケット損失率がゼロの場合、常に良好に動作する場合は、PLRパフォーマンスメトリックは、ある程度有効です。いくつかの用途は、高損失(バースト損失)の短い期間に敏感であり、単離されたパケット損失イベントに対して比較的鈍感です。このタイプのアプリケーションのために、PLRとアプリケーションのパフォーマンスの間に非常に弱い相関関係が存在することになります。 「より良い」パフォーマンスメトリックは、パケット損失率および損失事象の分布の両方を検討します。 PLRは、いくつかのレートを超えた場合に、アプリケーションのパフォーマンスが低下している場合には、有用なパフォーマンスメトリックは、PLRレート(例えば、としてRFC 3611で)ことを超えている期間の持続時間および周波数の測定値であってもよいです。

5.3. Computed Performance Metrics
5.3. 計算されたパフォーマンス・メトリック
5.3.1. Composed Performance Metrics
5.3.1. 作曲パフォーマンス・メトリック

Some Performance Metrics may not be measured directly, but can be composed from base metrics that have been measured. A composed Performance Metric is derived from other metrics by applying a deterministic process or function (e.g., a composition function). The process may use metrics that are identical to the metric being composed, or metrics that are dissimilar, or some combination of both types. Usually, the base metrics have a limited scope in time or space, and they can be combined to estimate the performance of some larger entities.


Some examples of composed Performance Metrics and composed Performance Metric definitions are as follows:


Spatial composition is defined as the composition of metrics of the same type with differing spatial domains [RFC5835] [RFC6049]. Ideally, for spatially composed metrics to be meaningful, the spatial domains should be non-overlapping and contiguous, and the composition operation should be mathematically appropriate for the type of metric.


Temporal composition is defined as the composition of sets of metrics of the same type with differing time spans [RFC5835]. For temporally composed metrics to be meaningful, the time spans should be non-overlapping and contiguous, and the composition operation should be mathematically appropriate for the type of metric.


Temporal aggregation is a summarization of metrics into a smaller number of metrics that relate to the total time span covered by the original metrics. An example would be to compute the minimum, maximum, and average values of a series of time-sampled values of a metric.


In the context of flow records in IP Flow Information eXport (IPFIX), the IPFIX Mediation Framework [RFC6183], based on "IP Flow Information Export (IPFIX) Mediation: Problem Statement" [RFC5982], also discusses some aspects of the temporal and spatial composition.


5.3.2. Index
5.3.2. 指数

An index is a metric for which the output value range has been selected for convenience or clarity, and the behavior of which is selected to support ease of understanding, for example, the R Factor [G.107]. The deterministic function for an index is often developed after the index range and behavior have been determined.


5.4. Performance Metric Specification
5.4. パフォーマンスメトリック仕様
5.4.1. Outline
5.4.1. 概要

A Performance Metric definition MUST have a normative part that defines what the metric is and how it is measured or computed, and it SHOULD have an informative part that describes the Performance Metric and its application.


5.4.2. Normative Parts of Performance Metric Definition
5.4.2. パフォーマンスメトリックの定義の規範パーツ

The normative part of a Performance Metric definition MUST define at least the following:


(i) Metric Name


Performance Metric names are RECOMMENDED to be unique within the set of metrics being defined for the protocol layer and context. While strict uniqueness may not be attainable (see the IPPM registry [RFC6248] for an example of an IANA metric registry failing to provide sufficient specificity), broad review must be sought to avoid naming overlap. Note that the Performance Metrics Directorate can help with suggestions for IANA metric registration for unique naming. The Performance Metric name MAY be descriptive.


(ii) Metric Description


The Performance Metric description MUST explain what the metric is, what is being measured, and how this relates to the performance of the system being measured.


(iii) Method of Measurement or Calculation


The method of measurement or calculation MUST define what is being measured or computed and the specific algorithm to be used. Does the measurement involve active or only passive measurements? Terms such as "average" should be qualified (e.g., running average or average over some interval). Exception cases SHOULD also be defined with the appropriate handling method. For example, there are a number of commonly used metrics related to packet loss; these often don't define the criteria by which a packet is determined to be lost (versus very delayed) or how duplicate packets are handled. For example, if the average PLR during a time interval is reported, and a packet's arrival is delayed from one interval to the next, then was it "lost" during the interval during which it should have arrived or should it be counted as received?


Some methods of calculation might require discarding some data collected (due to outliers) so as to make the measurement parameters meaningful. One example is burstable billing that sorts the 5-min samples and discards the top 5 percentile.


Some parameters linked to the method MAY also be reported, in order to fully interpret the Performance Metric, for example, the time interval, the load, the minimum packet loss, the potential measurement errors and their sources, the attainable accuracy of the metric (e.g., +/- 0.1), the method of calculation, etc.

方法にリンクされているいくつかのパラメータは、完全にパフォーマンスメトリック、例えば、時間間隔、負荷、最小パケット損失、電位測定誤差とそのソース、メトリックの達成可能な精度を(解釈するために、報告することができます例えば+/- 0.1)、計算方法、等

(iv) Units of Measurement


The units of measurement MUST be clearly stated.


(v) Measurement Point(s) with Potential Measurement Domain


If the measurement is specific to a measurement point, this SHOULD be defined. The measurement domain MAY also be defined. Specifically, if measurement points are spread across domains, the measurement domain (intra-, inter-) is another factor to consider.


The Performance Metric definition should discuss how the Performance Metric value might vary, depending on which measurement point is chosen. For example, the time between a SIP request [RFC3261] and the final response can be significantly different at the User Agent Client (UAC) or User Agent Server (UAS).


In some cases, the measurement requires multiple measurement points: all measurement points SHOULD be defined, including the measurement domain(s).


(vi) Measurement Timing


The acceptable range of timing intervals or sampling intervals for a measurement, and the timing accuracy required for such intervals, MUST be specified. Short sampling intervals or frequent samples provide a rich source of information that can help assess application performance but may lead to excessive measurement data. Long measurement or sampling intervals reduce the amount of reported and collected data such that it may be insufficient to understand application performance or service quality, insofar as the measured quantity may vary significantly with time.


In the case of multiple measurement points, the potential requirement for synchronized clocks must be clearly specified. In the specific example of the IP delay variation application metric, the different aspects of synchronized clocks are discussed in [RFC5481].

複数の測定点の場合には、同期クロックのための潜在的な要件は、明確に指定しなければなりません。 IP遅延変動アプリケーションメトリックの具体例では、同期クロックの異なる態様は、[RFC5481]に記載されています。

5.4.3. Informative Parts of Performance Metric Definition
5.4.3. パフォーマンスメトリックの定義の有益なパーツ

The informative part of a Performance Metric specification is intended to support the implementation and use of the metric. This part SHOULD provide the following data:


(i) Implementation


The implementation description MAY be in the form of text, an algorithm, or example software. The objective of this part of the metric definition is to help implementers achieve consistent results.


(ii) Verification


The Performance Metric definition SHOULD provide guidance on verification testing. This may be in the form of test vectors, a formal verification test method, or informal advice.


(iii) Use and Applications


The use and applications description is intended to help the "user" understand how, when, and where the metric can be applied, and what significance the value range for the metric may have. This MAY include a definition of the "typical" and "abnormal" range of the Performance Metric, if this was not apparent from the nature of the metric. The description MAY include information about the influence of extreme measurement values, i.e., if the Performance Metric is sensitive to outliers. The Use and Application section SHOULD also include the security implications in the description.


For example:


(a) it is fairly intuitive that a lower packet loss ratio would equate to better performance. However, the user may not know the significance of some given packet loss ratio.


(b) the speech level of a telephone signal is commonly expressed in dBm0. If the user is presented with:


Speech level = -7 dBm0

スピーチレベル= -7 dBm0で

this is not intuitively understandable, unless the user is a telephony expert. If the metric definition explains that the typical range is -18 to -28 dBm0, a value higher than -18 means the signal may be too high (loud), and less than -28 means that the signal may be too low (quiet), it is much easier to interpret the metric.

ユーザーは、電話の専門家でない限り、これは、直感的に理解できないです。メトリック定義は、典型的な範囲は-18 -28にdBm0で、であると説明した場合(静か)-18より高い値は、信号が(大音量)が高すぎる可能性があることを意味し、そして-28未満では、信号が低すぎる可能性があることを意味しますメトリックを解釈する方がはるかに簡単です。

(iv) Reporting Model


The reporting model definition is intended to make any relationship between the metric and the reporting model clear. There are often implied relationships between the method of reporting metrics and the metric itself; however, these are often not made apparent to the implementor. For example, if the metric is a short-term running average packet delay variation (e.g., the inter-arrival jitter in [RFC3550]) and this value is reported at intervals of 6-10 seconds, the resulting measurement may have limited accuracy when packet delay variation is non-stationary.


5.4.4. Performance Metric Definition Template
5.4.4. パフォーマンスメトリック定義テンプレート



o Metric Name


o Metric Description


o Method of Measurement or Calculation


o Units of Measurement


o Measurement Point(s) with Potential Measurement Domain


o Measurement Timing




o Implementation


o Verification


o Use and Applications


o Reporting Model


5.4.5. Example: Loss Rate
5.4.5. 例:ロス率

The example used is the loss rate metric as specified in RFC 3611 [RFC3611].

RFC 3611 [RFC3611]で指定されるように使用される例では、損失率メトリックです。

Metric Name: LossRate


Metric Description: The fraction of RTP data packets from the source lost since the beginning of reception.


Method of Measurement or Calculation: This value is calculated by dividing the total number of packets lost (after the effects of applying any error protection, such as Forward Error Correction (FEC)) by the total number of packets expected, multiplying the result of the division by 256, limiting the maximum value to 255 (to avoid overflow), and taking the integer part.


Units of Measurement: This metric is expressed as a fixed-point number with the binary point at the left edge of the field. For example, a metric value of 12 means a loss rate of approximately 5%.


Measurement Point(s) with Potential Measurement Domain: This metric is made at the receiving end of the RTP stream sent during a Voice over IP call.


Measurement Timing: This metric can be used over a wide range of time intervals. Using time intervals of longer than one hour may prevent the detection of variations in the value of this metric due to time-of-day changes in network load. Timing intervals should not vary in duration by more than +/- 2%.

測定タイミング:このメトリックは、時間間隔の広い範囲で使用することができます。 1時間以上の時間間隔を使用することにより、ネットワーク負荷の時刻変化にこのメトリックの値の変化の検出を防止することができます。タイミング間隔以上+/- 2%持続時間において変化しないはずです。

Implementation: The numbers of duplicated packets and discarded packets do not enter into this calculation. Since receivers cannot be required to maintain unlimited buffers, a receiver MAY categorize late-arriving packets as lost. The degree of lateness that triggers a loss SHOULD be significantly greater than that which triggers a discard.


Verification: The metric value ranges between 0 and 255.


Use and Applications: This metric is useful for monitoring VoIP calls, more precisely, to detect the VoIP loss rate in the network. This loss rate, along with the rate of packets discarded due to jitter, has some effect on the quality of the voice stream.


Reporting Model: This metric needs to be associated with a defined time interval, which could be defined by fixed intervals or by a sliding window. In the context of RFC 3611, the metric is measured continuously from the start of the RTP stream, and the value of the metric is sampled and reported in RTCP XR VoIP Metrics reports.

モデルレポート:このメトリックは、一定の間隔によって、またはスライディングウィンドウによって定義することができる定義された時間間隔に関連付けられる必要があります。 RFC 3611の文脈では、メトリックは、RTPストリームの開始から連続的に測定され、メトリックの値をサンプリングし、RTCP XR VoIPのメトリクスに報告する報告されています。

5.5. Dependencies
5.5. 依存関係

This section introduces several Performance Metrics dependencies, which the Performance Metric designer should keep in mind during Performance Metric development. These dependencies, and any others not listed here, SHOULD be documented in the Performance Metric specifications.


5.5.1. Timing Accuracy
5.5.1. タイミング精度

The accuracy of the timing of a measurement may affect the accuracy of the Performance Metric. This may not materially affect a sampled-value metric; however, it would affect an interval-based metric. Some metrics -- for example, the number of events per time interval -- would be directly affected; for example, a 10% variation in time interval would lead directly to a 10% variation in the measured value. Other metrics, such as the average packet loss ratio during some time interval, would be affected to a lesser extent.

測定のタイミングの精度は、パフォーマンスメトリックの精度に影響を与える可能性があります。これは、実質サンプリングされた値のメトリックに影響を与えないかもしれません。しかし、それは間隔ベースのメトリックに影響を与えるでしょう。いくつかの測定基準 - 例えば、時間間隔あたりのイベント数 - 直接影響を受けるであろう。例えば、時間間隔中の10%の変動は、測定値の10%の変化に直接つながります。そのようないくつかの時間間隔の間の平均パケット損失率のような他のメトリックが、より少ない程度に影響を受けることになります。

If it is necessary to correlate sampled values or intervals, then it is essential that the accuracy of sampling time and interval start/ stop times is sufficient for the application (for example, +/- 2%).


5.5.2. Dependencies of Performance Metric Definitions on Related Events or Metrics

5.5.2. 関連イベントまたはメトリックのパフォーマンスメトリックの定義の依存関係

Performance Metric definitions may explicitly or implicitly rely on factors that may not be obvious. For example, the recognition of a packet as being "lost" relies on having some method of knowing the packet was actually lost (e.g., RTP sequence number), and some time threshold after which a non-received packet is declared lost. It is important that any such dependencies are recognized and incorporated into the metric definition.


5.5.3. Relationship between Performance Metric and Lower-Layer Performance Metrics

5.5.3. パフォーマンスメトリックと下層のパフォーマンス・メトリックの関係

Lower-layer Performance Metrics may be used to compute or infer the performance of higher-layer applications, potentially using an application performance model. The accuracy of this will depend on many factors, including:


(i) The completeness of the set of metrics (i.e., are there metrics for all the input values to the application performance model?)


(ii) Correlation between input variables (being measured) and application performance


(iii) Variability in the measured metrics and how this variability affects application performance


5.5.4. Middlebox Presence
5.5.4. ミドルプレゼンス

Presence of a middlebox [RFC3303], e.g., proxy, network address translation (NAT), redirect server, session border controller (SBC) [RFC5853], and application layer gateway (ALG), may add variability to or restrict the scope of measurements of a metric. For example, an SBC that does not process RTP loopback packets may block or locally terminate this traffic rather than pass it through to its target.


5.6. Organization of Results
5.6. 結果の整理

The IPPM Framework [RFC2330] organizes the results of metrics into three related notions:


o singleton: an elementary instance, or "atomic" value.


o sample: a set of singletons with some common properties and some varying properties.


o statistic: a value derived from a sample through deterministic calculation, such as the mean.


Performance Metrics MAY use this organization for the results, with or without the term names used by the IPPM WG. Section 11 of RFC 2330 [RFC2330] should be consulted for further details.

パフォーマンス・メトリックは、またはIPPM WGで使用される用語名なしで、結果のためにこの組織を使用するかもしれません。 RFC 2330のセクション11 [RFC2330]は、さらに詳細のために相談する必要があります。

5.7. Parameters: the Variables of a Performance Metric
5.7. パラメータ:パフォーマンスメトリックの変数

Metrics are completely defined when all options and input variables have been identified and considered. These variables are sometimes left unspecified in a metric definition, and their general name indicates that the user must set and report them with the results. Such variables are called "parameters" in the IPPM metric template. The scope of the metric, the time at which it was conducted, the length interval of the sliding-window measurement, the settings for timers, and the thresholds for counters are all examples of parameters.


All documents defining Performance Metrics SHOULD identify all key parameters for each Performance Metric.


6. Performance Metric Development Process
6.1. New Proposals for Performance Metrics
6.1. パフォーマンス・メトリックのための新しい提案

This process is intended to add more considerations to the processes for adopting new work as described in RFC 2026 [RFC2026] and RFC 2418 [RFC2418]. Note that new Performance Metrics work item proposals SHALL be approved using the existing IETF process. The following entry criteria will be considered for each proposal.

このプロセスは、RFC 2026 [RFC2026]およびRFC 2418 [RFC2418]で説明したように新しい仕事を採用するためのプロセスに多くの考慮事項を追加することを意図しています。新しいパフォーマンス・メトリックの作業項目の提案は、既存のIETFプロセスを使用して承認を得なければならないことに注意してください。次のエントリ基準は各提案のために考慮されます。

Proposals SHOULD be prepared as Internet-Drafts, describing the Performance Metric and conforming to the qualifications above as much as possible. Proposals SHOULD be deliverables of the corresponding protocol development WG charters. As such, the proposals SHOULD be vetted by that WG prior to discussion by the Performance Metrics Directorate. This aspect of the process includes an assessment of the need for the Performance Metric proposed and assessment of the support for its development in the IETF.


Proposals SHOULD include an assessment of interaction and/or overlap with work in other Standards Development Organizations (SDOs). Proposals SHOULD identify additional expertise that might be consulted.


Proposals SHOULD specify the intended audience and users of the Performance Metrics. The development process encourages participation by members of the intended audience.


Proposals SHOULD identify any security and IANA requirements. Security issues could potentially involve revealing data identifying a user, or the potential misuse of active test tools. IANA considerations may involve the need for a Performance Metrics registry.

提案はすべてのセキュリティとIANA要件を特定する必要があります。セキュリティの問題は、潜在的ユーザー、またはアクティブなテストツールの誤用の可能性を特定する発現情報を必要とすることができます。 IANAの考慮事項は、パフォーマンス・メトリックのレジストリの必要性を伴うことがあります。

6.2. Reviewing Metrics
6.2. メトリックの確認

Each Performance Metric SHOULD be assessed according to the following list of qualifications:


o Are the performance metrics unambiguously defined?


o Are the units of measure specified?


o Does the metric clearly define the measurement interval where applicable?


o Are significant sources of measurement errors identified and discussed?


o Does the method of measurement ensure that results are repeatable?


o Does the metric or method of measurement appear to be implementable (or offer evidence of a working implementation)?


o Are there any undocumented assumptions concerning the underlying process that would affect an implementation or interpretation of the metric?


o Can the metric results be related to application performance or user experience, when such a relationship is of value?


o Is there an existing relationship to metrics defined elsewhere within the IETF or within other SDOs?

O IETF内またはその他のSDO内の他の場所に定義されたメトリックの既存の関係がありますか?

o Do the security considerations adequately address denial-of-service attacks, unwanted interference with the metric/ measurement, and user data confidentiality (when measuring live traffic)?


6.3. Performance Metrics Directorate Interaction with Other WGs
6.3. その他のWGでのパフォーマンス・メトリック総局の相互作用

The Performance Metrics Directorate SHALL provide guidance to the related protocol development WG when considering an Internet-Draft that specifies Performance Metrics for a protocol. A sufficient number of individuals with expertise must be willing to consult on the draft. If the related WG has concluded, comments on the proposal should still be sought from key RFC authors and former chairs.


As with expert reviews performed by other directorates, a formal review is recommended by the time the document is reviewed by the Area Directors or an IETF Last Call is being conducted.


Existing mailing lists SHOULD be used; however, a dedicated mailing list MAY be initiated if necessary to facilitate work on a draft.


In some cases, it will be appropriate to have the IETF session discussion during the related protocol WG session, to maximize visibility of the effort to that WG and expand the review.


6.4. Standards Track Performance Metrics
6.4. 標準化過程パフォーマンス・メトリック

The Performance Metrics Directorate will assist with the progression of RFCs along the Standards Track. See [IPPM-STANDARD-ADV-TESTING]. This may include the preparation of test plans to examine different implementations of the metrics to ensure that the metric definitions are clear and unambiguous (depending on the final form of the draft mentioned above).

パフォーマンス・メトリック総局は標準化過程に沿ってRFCの進行を支援します。 [IPPM-STANDARD-ADV-TESTING]を参照してください。これは、メトリックの定義は(上記案の最終的な形態に応じて)明確かつ明白であることを保証するために、メトリクスの異なる実装を検討するテストプランの準備を含んでいてもよいです。

7. Security Considerations

In general, the existence of a framework for Performance Metric development does not constitute a security issue for the Internet. Performance Metric definitions, however, may introduce security issues, and this framework recommends that persons defining Performance Metrics should identify any such risk factors.


The security considerations that apply to any active measurement of live networks are relevant here. See [RFC4656].

ライブネットワークの任意のアクティブな測定に適用するセキュリティ上の考慮事項はここでは関係しています。 [RFC4656]を参照してください。

The security considerations that apply to any passive measurement of specific packets in live networks are relevant here as well. See the security considerations in [RFC5475].

ライブネットワーク内の特定のパケットのいずれかの受動的測定に適用されるセキュリティ上の考慮事項はここにも関連しています。 [RFC5475]のセキュリティの考慮事項を参照してください。

8. Acknowledgements

The authors would like to thank Al Morton, Dan Romascanu, Daryl Malas, and Loki Jorgenson for their comments and contributions, and Aamer Akhter, Yaakov Stein, Carsten Schmoll, and Jan Novak for their reviews.

作者は彼らのレビューのためにアル・モートン、ダンRomascanu、ダリル・マラス、とロキJorgenson彼らのコメントと貢献のため、およびAamer Akhter、Yaakovのスタイン、カールステンSchmoll、とJanノバックに感謝したいと思います。

9. References
9.1. Normative References
9.1. 引用規格

[RFC2026] Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996.

[RFC2026]ブラドナーの、S.、 "インターネット標準化プロセス - リビジョン3"、BCP 9、RFC 2026、1996年10月。

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2119]ブラドナーの、S.、 "要件レベルを示すためにRFCsにおける使用のためのキーワード"、BCP 14、RFC 2119、1997年3月。

[RFC2418] Bradner, S., "IETF Working Group Guidelines and Procedures", BCP 25, RFC 2418, September 1998.

[RFC2418]ブラドナーの、S.、 "IETFワーキンググループガイドラインと手順"、BCP 25、RFC 2418、1998年9月。

[RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. Zekauskas, "A One-way Active Measurement Protocol (OWAMP)", RFC 4656, September 2006.

[RFC4656] Shalunov、S.、Teitelbaum、B.、カープ、A.、BOOTE、J.、およびM. Zekauskas、 "ワンウェイアクティブな測定プロトコル(OWAMP)"、RFC 4656、2006年9月。

9.2. Informative References
9.2. 参考文献


[E.800] "ITU-T勧告E.800 Eシリーズ:ネットワーク全体の動作、電話サービス、サービスの操作とヒューマンファクター"、2008年9月。

[G.107] "ITU-T Recommendation G.107. The E-model: a computational model for use in transmission planning", April 2009.

[G.107] "ITU-T勧告G.107 E-モデル:伝送計画で使用するための計算モデル"、2009年4月。

[IPPM-STANDARD-ADV-TESTING] Geib, R., Ed., Morton, A., Fardid, R., and A. Steinmitz, "IPPM standard advancement testing", Work in Progress, June 2011.

[IPPM-STANDARD-ADV-TESTING] Geib、R.、エド。、モートン、A.、Fardid、R.、およびA. Steinmitz、 "IPPM標準前進テスト"、進歩、2011年6月での作業。

[P.564] "ITU-T Recommendation P.564. Conformance Testing for Voice over IP Transmission Quality Assessment Models", November 2007.

[P.564] "ITU-T勧告P.564。IP伝送品質評価モデル、ボイスオーバーのための適合性試験"、2007年11月。

[P.800] "ITU-T Recommendation P.800. Methods for subjective determination of transmission quality", August 1996.

[P.800] "ITU-T勧告P.800。伝送品質の主観的な決定のための方法"、1996年8月。

[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, September 1981.

[RFC0793]ポステル、J.、 "伝送制御プロトコル"、STD 7、RFC 793、1981年9月。

[RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP Performance Metrics", RFC 2330, May 1998.

[RFC2330]パクソン、V.、Almes、G.、Mahdavi、J.、およびM.マティス、 "IPパフォーマンス・メトリックのためのフレームワーク"、RFC 2330、1998年5月。

[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002.

[RFC3261]ローゼンバーグ、J.、Schulzrinneと、H.、カマリロ、G.、ジョンストン、A.、ピーターソン、J.、スパークス、R.、ハンドレー、M.、およびE.学生、 "SIP:セッション開始プロトコル" 、RFC 3261、2002年6月。

[RFC3303] Srisuresh, P., Kuthan, J., Rosenberg, J., Molitor, A., and A. Rayhan, "Middlebox communication architecture and framework", RFC 3303, August 2002.

[RFC3303] Srisuresh、P.、Kuthan、J.、ローゼンバーグ、J.、モリター、A.、およびA. Rayhan、 "ミドル通信アーキテクチャおよびフレームワーク"、RFC 3303、2002年8月。

[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications", STD 64, RFC 3550, July 2003.

[RFC3550] Schulzrinneと、H.、Casner、S.、フレデリック、R.、およびV.ヤコブソン、 "RTP:リアルタイムアプリケーションのためのトランスポートプロトコル"、STD 64、RFC 3550、2003年7月。

[RFC3611] Friedman, T., Ed., Caceres, R., Ed., and A. Clark, Ed., "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, November 2003.

[RFC3611]フリードマン、T.、エド。、カセレス、R.、エド。、およびA.クラーク、エド。、 "RTP制御プロトコルの拡張レポート(RTCP XR)"、RFC 3611、2003年11月。

[RFC4710] Siddiqui, A., Romascanu, D., and E. Golovinsky, "Real-time Application Quality-of-Service Monitoring (RAQMON) Framework", RFC 4710, October 2006.

[RFC4710] Siddiqui著、A.、Romascanu、D.、およびE. Golovinsky、 "リアルタイムアプリケーションサービス品質のモニタリング(RAQMON)フレームワーク"、RFC 4710、2006年10月。

[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol", RFC 4960, September 2007.

[RFC4960]スチュワート、R.、エド。、 "ストリーム制御伝送プロトコル"、RFC 4960、2007年9月。

[RFC5101] Claise, B., Ed., "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information", RFC 5101, January 2008.

[RFC5101] Claise、B.、エド。、RFC 5101、2008年1月 "IPトラフィックフロー情報を交換するためのIPフロー情報のエクスポート(IPFIX)プロトコルの仕様"。

[RFC5102] Quittek, J., Bryant, S., Claise, B., Aitken, P., and J. Meyer, "Information Model for IP Flow Information Export", RFC 5102, January 2008.

[RFC5102] Quittek、J.、ブライアント、S.、Claise、B.、エイトケン、P.、およびJ.マイヤー、 "IPフロー情報のエクスポートのための情報モデル"、RFC 5102、2008年1月。

[RFC5474] Duffield, N., Ed., Chiou, D., Claise, B., Greenberg, A., Grossglauser, M., and J. Rexford, "A Framework for Packet Selection and Reporting", RFC 5474, March 2009.

[RFC5474]ダフィールド、N.編、Chiou、D.、Claise、B.、グリーンバーグ、A.、Grossglauser、M.、およびJ. Rexfordの、 "パケット選択及び報告のための枠組み"、RFC 5474年3月2009。

[RFC5475] Zseby, T., Molina, M., Duffield, N., Niccolini, S., and F. Raspall, "Sampling and Filtering Techniques for IP Packet Selection", RFC 5475, March 2009.

[RFC5475] Zseby、T.、モリーナ、M.、ダッフィールド、N.、ニッコリーニ、S.、およびF. Raspall、 "IPパケットの選択のためのサンプリングとフィルタリング技術"、RFC 5475、2009年3月。

[RFC5481] Morton, A. and B. Claise, "Packet Delay Variation Applicability Statement", RFC 5481, March 2009.

[RFC5481]モートン、A.およびB. Claise、 "パケット遅延変動の適用に関する声明"、RFC 5481、2009年3月。

[RFC5706] Harrington, D., "Guidelines for Considering Operations and Management of New Protocols and Protocol Extensions", RFC 5706, November 2009.

[RFC5706]ハリントン、D.、RFC 5706、2009年11月「新しいプロトコルやプロトコル拡張の運用と管理を考えるためのガイドライン」。

[RFC5835] Morton, A., Ed., and S. Van den Berghe, Ed., "Framework for Metric Composition", RFC 5835, April 2010.

[RFC5835]モートン、A.編、及びS.ヴァンデンベルグフ編、 "メトリック組成物のためのフレームワーク"、RFC 5835、2010年4月。

[RFC5853] Hautakorpi, J., Ed., Camarillo, G., Penfield, R., Hawrylyshen, A., and M. Bhatia, "Requirements from Session Initiation Protocol (SIP) Session Border Control (SBC) Deployments", RFC 5853, April 2010.

[RFC5853] Hautakorpi、J.、編、カマリロ、G.、ペンフィールド、R.、Hawrylyshen、A.、およびM. Bhatiaは、 "セッション開始プロトコル(SIP)セッションボーダーコントロール(SBC)デプロイメントの要件"、RFC 5853、2010年4月。

[RFC5982] Kobayashi, A., Ed., and B. Claise, Ed., "IP Flow Information Export (IPFIX) Mediation: Problem Statement", RFC 5982, August 2010.

。。[RFC5982]小林、A.、エド、およびB. Claise、エド、 "IPフロー情報のエクスポート(IPFIX)調停:問題文"、RFC 5982、2010年8月。

[RFC6035] Pendleton, A., Clark, A., Johnston, A., and H. Sinnreich, "Session Initiation Protocol Event Package for Voice Quality Reporting", RFC 6035, November 2010.

[RFC6035]ペンドルトン、A.、クラーク、A.、ジョンストン、A.、およびH. Sinnreich、 "音声品質報告のためのセッション開始プロトコルイベントパッケージ"、RFC 6035、2010年11月。

[RFC6049] Morton, A. and E. Stephan, "Spatial Composition of Metrics", RFC 6049, January 2011.

[RFC6049]モートン、A.及びE.ステファン、 "メトリックの空間構成"、RFC 6049、2011年1月。

[RFC6183] Kobayashi, A., Claise, B., Muenz, G., and K. Ishibashi, "IP Flow Information Export (IPFIX) Mediation: Framework", RFC 6183, April 2011.

[RFC6183]小林、A.、Claise、B.、Muenz、G.、及びK.石橋、 "IPフロー情報エクスポート(IPFIX)メディエーション:フレームワーク"、RFC 6183、2011年4月。

[RFC6248] Morton, A., "RFC 4148 and the IP Performance Metrics (IPPM) Registry of Metrics Are Obsolete", RFC 6248, April 2011.

[RFC6248]モートン、A.、 "RFC 4148およびIPパフォーマンス・メトリック(IPPM)メトリクスのレジストリは廃止されています"、RFC 6248、2011年4月。

Authors' Addresses


Alan Clark Telchemy Incorporated 2905 Premiere Parkway, Suite 280 Duluth, Georgia 30097 USA

アラン・クラークTelchemy株式会社2905プレミアパークウェイ、スイート280ダルース、ジョージア州30097 USA



Benoit Claise Cisco Systems, Inc. De Kleetlaan 6a b1 Diegem 1831 Belgium

ブノワClaiseシスコシステムズ、株式会社デKleetlaan 6aはB1のディーゲム1831ベルギー

Phone: +32 2 704 5622 EMail:

電話:+32 2 704 5622 Eメール