draft-ietf-ippm-framework-compagg-08.txt   draft-ietf-ippm-framework-compagg-09.txt 
Network Working Group A. Morton, Ed. Network Working Group A. Morton, Ed.
Internet-Draft AT&T Labs Internet-Draft AT&T Labs
Intended status: Informational S. Van den Berghe, Ed. Intended status: Informational S. Van den Berghe, Ed.
Expires: December 23, 2009 Ghent University - IBBT Expires: June 23, 2010 Alcatel-Lucent
June 21, 2009 December 20, 2009
Framework for Metric Composition Framework for Metric Composition
draft-ietf-ippm-framework-compagg-08 draft-ietf-ippm-framework-compagg-09
Abstract
This memo describes a detailed framework for composing and
aggregating metrics (both in time and in space) originally defined by
the IP Performance Metrics (IPPM) RFC 2330 and developed by the IETF.
This new framework memo describes the generic composition and
aggregation mechanisms. The memo provides a basis for additional
documents that implement the framework to define detailed
compositions and aggregations of metrics which are useful in
practice.
Requirements Language
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].
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. This document may contain material provisions of BCP 78 and BCP 79.
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.
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Copyright Notice Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of Provisions Relating to IETF Documents
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Please review these documents carefully, as they describe your rights publication of this document. Please review these documents
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to this document. Code Components extracted from this document must
Abstract include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
This memo describes a detailed framework for composing and described in the BSD License.
aggregating metrics (both in time and in space) originally defined by
the IP Performance Metrics (IPPM) RFC 2330 and developed by the IETF.
This new framework memo describes the generic composition and
aggregation mechanisms. The memo provides a basis for additional
documents that implement the framework to define detailed
compositions and aggregations of metrics which are useful in
practice.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", This document may contain material from IETF Documents or IETF
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this Contributions published or made publicly available before November
document are to be interpreted as described in RFC 2119 [RFC2119]. 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 Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1.1. Reducing Measurement Overhead . . . . . . . . . . . . 4 1.1.1. Reducing Measurement Overhead . . . . . . . . . . . . 4
1.1.2. Measurement Re-use . . . . . . . . . . . . . . . . . . 5 1.1.2. Measurement Re-use . . . . . . . . . . . . . . . . . . 5
1.1.3. Data Reduction and Consolidation . . . . . . . . . . . 5 1.1.3. Data Reduction and Consolidation . . . . . . . . . . . 5
1.1.4. Implications on Measurement Design and Reporting . . . 6 1.1.4. Implications on Measurement Design and Reporting . . . 6
2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 6 2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 6
skipping to change at page 3, line 47 skipping to change at page 3, line 47
6.1.2. Ground Truth for Spatial Aggregation . . . . . . . . . 15 6.1.2. Ground Truth for Spatial Aggregation . . . . . . . . . 15
6.2. Deviation from the Ground Truth . . . . . . . . . . . . . 15 6.2. Deviation from the Ground Truth . . . . . . . . . . . . . 15
6.3. Incomplete Information . . . . . . . . . . . . . . . . . . 15 6.3. Incomplete Information . . . . . . . . . . . . . . . . . . 15
6.4. Time Varying Metrics . . . . . . . . . . . . . . . . . . . 15 6.4. Time Varying Metrics . . . . . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
8. Security Considerations . . . . . . . . . . . . . . . . . . . 16 8. Security Considerations . . . . . . . . . . . . . . . . . . . 16
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.1. Normative References . . . . . . . . . . . . . . . . . . . 16 10.1. Normative References . . . . . . . . . . . . . . . . . . . 16
10.2. Informative References . . . . . . . . . . . . . . . . . . 17 10.2. Informative References . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
The IPPM framework [RFC2330] describes two forms of metric The IPPM framework [RFC2330] describes two forms of metric
composition, spatial and temporal. The text also suggests that the composition, spatial and temporal. The text also suggests that the
concepts of the analytical framework (or A-frame) would help to concepts of the analytical framework (or A-frame) would help to
develop useful relationships to derive the composed metrics from real develop useful relationships to derive the composed metrics from real
metrics. The effectiveness of composed metrics is dependent on their metrics. The effectiveness of composed metrics is dependent on their
usefulness in analysis and applicability to practical measurement usefulness in analysis and applicability to practical measurement
circumstances. circumstances.
skipping to change at page 6, line 26 skipping to change at page 6, line 26
The purpose of this memo is provide a common framework for the The purpose of this memo is provide a common framework for the
various classes of metrics that are composed from primary metrics. various classes of metrics that are composed from primary metrics.
The scope is limited to the definitions of metrics that are composed The scope is limited to the definitions of metrics that are composed
from primary metrics using a deterministic function. Key information from primary metrics using a deterministic function. Key information
about each composed metric, such as the assumptions under which the about each composed metric, such as the assumptions under which the
relationship holds and possible sources of error/circumstances where relationship holds and possible sources of error/circumstances where
the composition may fail, are included. the composition may fail, are included.
At this time, the scope of effort is limited to composed metrics for At this time, the scope of effort is limited to composed metrics for
packet loss, delay, and delay variation. Composition of packet packet loss, delay, and delay variation, as defined in [RFC2679],
reordering metrics is considered a research topic at the time this [RFC2680], [RFC2681], [RFC3393], [RFC5481], and the comparable
memo was prepared, and beyond its scope. metrics in [Y.1540] . Composition of packet reordering metrics
[RFC4737] and duplication metrics [RFC5560] are considered research
topics at the time this memo was prepared, and beyond its scope.
This memo will retain the terminology of the IPPM Framework This memo will retain the terminology of the IPPM Framework
[RFC2330]as much as possible, but will extend the terminology when [RFC2330]as much as possible, but will extend the terminology when
necessary. It is assumed that the reader is familiar with the necessary. It is assumed that the reader is familiar with the
concepts introduced in [RFC2330], as they will not be repeated here. concepts introduced in [RFC2330], as they will not be repeated here.
3. Terminology 3. Terminology
This section defines the terminology applicable to the processes of This section defines the terminology applicable to the processes of
Metric Composition and Aggregation. Metric Composition and Aggregation.
skipping to change at page 8, line 19 skipping to change at page 8, line 19
3.10. Sub-path 3.10. Sub-path
A Sub-path is a portion of the complete path where at least the Sub- A Sub-path is a portion of the complete path where at least the Sub-
path Source and Destination hosts are constituents of the complete path Source and Destination hosts are constituents of the complete
path. We say that such a sub-path is "involved" in the complete path. We say that such a sub-path is "involved" in the complete
path. path.
Since sub-paths terminate on hosts, it is important to describe how Since sub-paths terminate on hosts, it is important to describe how
sub-paths are considered to be joined. In practice, the Source and sub-paths are considered to be joined. In practice, the Source and
Desitination hosts may perform the funtion of measurement points. Destination hosts may perform the function of measurement points.
If the Destination and Source hosts of two adjoining paths are co- If the Destination and Source hosts of two adjoining paths are co-
located and the link between them would contribute negligible located and the link between them would contribute negligible
performance, then these hosts can be considered equivalent (even if performance, then these hosts can be considered equivalent (even if
there is no physical link between them, this is a practical there is no physical link between them, this is a practical
consession). concession).
If the Destination and Source hosts of two adjoining paths have a If the Destination and Source hosts of two adjoining paths have a
link between them that contributes to the complete path performance, link between them that contributes to the complete path performance,
then the link and hosts constitutes another sub-path that is involved then the link and hosts constitutes another sub-path that is involved
in the complete path, and should be characterized and included in the in the complete path, and should be characterized and included in the
composed metric. composed metric.
3.11. Sub-path Metrics 3.11. Sub-path Metrics
A sub-path path metric is an element of the process to derive a A sub-path path metric is an element of the process to derive a
skipping to change at page 9, line 5 skipping to change at page 9, line 5
space, and the third involves concatenation in space. space, and the third involves concatenation in space.
4.1. Temporal Aggregation Description 4.1. Temporal Aggregation Description
Aggregation in time is defined as the composition of metrics with the Aggregation in time is defined as the composition of metrics with the
same type and scope obtained in different time instants or time same type and scope obtained in different time instants or time
windows. For example, starting from a time series of the windows. For example, starting from a time series of the
measurements of maximum and minimum One-Way Delay on a certain measurements of maximum and minimum One-Way Delay on a certain
network path obtained over 5-minute intervals, we obtain a time network path obtained over 5-minute intervals, we obtain a time
series measurement with a coarser resolution (60 minutes) by taking series measurement with a coarser resolution (60 minutes) by taking
the max of 12 consecutive 5-minute maxima and the min of 12 the maximum of 12 consecutive 5-minute maxima and the minimum of 12
consecutive 5-minute minima. consecutive 5-minute minima.
The main reason for doing time aggregation is to reduce the amount of The main reason for doing time aggregation is to reduce the amount of
data that has to be stored, and make the visualization/spotting of data that has to be stored, and make the visualization/spotting of
regular cycles and/or growing or decreasing trends easier. Another regular cycles and/or growing or decreasing trends easier. Another
useful application is to detect anomalies or abnormal changes in the useful application is to detect anomalies or abnormal changes in the
network characteristics. network characteristics.
In RFC 2330, the term "temporal composition" is introduced and In RFC 2330, the term "temporal composition" is introduced and
differs from temporal aggregation in that it refers to methodologies differs from temporal aggregation in that it refers to methodologies
to predict future metrics on the basis of past observations (of the to predict future metrics on the basis of past observations (of the
same metrics), exploiting the time correlation that certain metrics same metrics), exploiting the time correlation that certain metrics
can exhibit. We do not consider this type of composition here. can exhibit. We do not consider this type of composition here.
>>>>>>>>Comment: Why no forecasting? This was apparently a limit on
the Geant2 project, but may not apply here.
4.2. Spatial Aggregation Description 4.2. Spatial Aggregation Description
Aggregation in space is defined as the combination of metrics of the Aggregation in space is defined as the combination of metrics of the
same type and different scope, in order to estimate the overall same type and different scope, in order to estimate the overall
performance of a larger network. This combination may involve performance of a larger network. This combination may involve
weighing the contributions of the input metrics. weighing the contributions of the input metrics.
Suppose we want to compose the average One-Way-Delay (OWD) Suppose we want to compose the average One-Way-Delay (OWD)
experienced by flows traversing all the Origin-Destination (OD) pairs experienced by flows traversing all the Origin-Destination (OD) pairs
of a network (where the inputs are already metric "statistics"). of a network (where the inputs are already metric "statistics").
skipping to change at page 13, line 39 skipping to change at page 13, line 39
++ ++ ++ ++ ++ ++ ++ ++
Figure 1: Comparison with other IPPM metrics Figure 1: Comparison with other IPPM metrics
The Composed Metric is an estimate of an actual metric collected over The Composed Metric is an estimate of an actual metric collected over
the complete Source to Destination path. We say that the Complete the complete Source to Destination path. We say that the Complete
Path Metric represents the "Ground Truth" for the Composed Metric. Path Metric represents the "Ground Truth" for the Composed Metric.
In other words, Composed Metrics seek to minimize error w.r.t. the In other words, Composed Metrics seek to minimize error w.r.t. the
Complete Path Metric. Complete Path Metric.
Further, we observe that a Spatial Metric Further, we observe that a Spatial Metric [RFC5644] collected for
[I-D.ietf-ippm-multimetrics] collected for packets traveling over the packets traveling over the same set of sub-paths provide a basis for
same set of sub-paths provide a basis for the Ground Truth of the the Ground Truth of the individual Sub-Path metrics. We note that
individual Sub-Path metrics. We note that mathematical operations mathematical operations may be necessary to isolate the performance
may be necessary to isolate the performance of each sub-path. of each sub-path.
Next, we consider multiparty metrics as defined in [I-D.ietf-ippm- Next, we consider multiparty metrics as defined in [RFC5644], and
multimetrics], and their spatial composition. Measurements to each their spatial composition. Measurements to each of the Receivers
of the Receivers produce an element of the one-to-group metric. produce an element of the one-to-group metric. These elements can be
These elements can be composed from sub-path metrics and the composed composed from sub-path metrics and the composed metrics can be
metrics can be combined to create a composed one-to-group metric. combined to create a composed one-to-group metric. Figure 2
Figure 2 illustrates this process. illustrates this process.
Sub-Path Metrics Sub-Path Metrics
++ M1 ++ ++ M2 ++ ++ M3 ++ ++ M1 ++ ++ M2 ++ ++ M3 ++
Src ||.......|| ||.......|| ||.......||Rcvr1 Src ||.......|| ||.......|| ||.......||Rcvr1
++ ++ ++`. ++ ++ ++ ++ ++ ++`. ++ ++ ++
`-. `-.
M4`.++ ++ M5 ++ M4`.++ ++ M5 ++
|| ||.......||Rcvr2 || ||.......||Rcvr2
++ ++`. ++ ++ ++`. ++
`-. `-.
skipping to change at page 16, line 43 skipping to change at page 16, line 43
Andreas Haneman, Igor Velimirovic, Andreas Solberg, Athanassios Andreas Haneman, Igor Velimirovic, Andreas Solberg, Athanassios
Liakopulos, David Schitz, Nicolas Simar and the Geant2 Project. We Liakopulos, David Schitz, Nicolas Simar and the Geant2 Project. We
also acknowledge comments and suggestions from Phil Chimento, Emile also acknowledge comments and suggestions from Phil Chimento, Emile
Stephan, Lei Liang, Stephen Wolff, Reza Fardid, Loki Jorgenson, and Stephan, Lei Liang, Stephen Wolff, Reza Fardid, Loki Jorgenson, and
Alan Clark. Alan Clark.
10. References 10. References
10.1. Normative References 10.1. Normative References
[I-D.ietf-ippm-multimetrics]
Stephan, E., Liang, L., and A. Morton, "IP Performance
Metrics (IPPM) for spatial and multicast",
draft-ietf-ippm-multimetrics-11 (work in progress),
April 2009.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis,
"Framework for IP Performance Metrics", RFC 2330, "Framework for IP Performance Metrics", RFC 2330,
May 1998. May 1998.
[RFC3979] Bradner, S., "Intellectual Property Rights in IETF [RFC3979] Bradner, S., "Intellectual Property Rights in IETF
Technology", BCP 79, RFC 3979, March 2005. Technology", BCP 79, RFC 3979, March 2005.
[RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. [RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M.
Zekauskas, "A One-way Active Measurement Protocol Zekauskas, "A One-way Active Measurement Protocol
(OWAMP)", RFC 4656, September 2006. (OWAMP)", RFC 4656, September 2006.
[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, October 2008. RFC 5357, October 2008.
10.2. Informative References 10.2. Informative References
[G.107] ITU-T Recommendation G.107, ""The E-model, a computational [RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
model for use in transmission planning"", March 2005. Delay Metric for IPPM", RFC 2679, September 1999.
[RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
Packet Loss Metric for IPPM", RFC 2680, September 1999.
[RFC2681] Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip
Delay Metric for IPPM", RFC 2681, September 1999.
[RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation
Metric for IP Performance Metrics (IPPM)", RFC 3393,
November 2002.
[RFC4737] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov,
S., and J. Perser, "Packet Reordering Metrics", RFC 4737,
November 2006.
[RFC5481] Morton, A. and B. Claise, "Packet Delay Variation
Applicability Statement", RFC 5481, March 2009.
[RFC5560] Uijterwaal, H., "A One-Way Packet Duplication Metric",
RFC 5560, May 2009.
[RFC5644] Stephan, E., Liang, L., and A. Morton, "IP Performance
Metrics (IPPM): Spatial and Multicast", RFC 5644,
October 2009.
[Y.1540] ITU-T Recommendation Y.1540, "Internet protocol data
communication service - IP packet transfer and
availability performance parameters", December 2007.
Authors' Addresses Authors' Addresses
Al Morton (editor) Al Morton (editor)
AT&T Labs AT&T Labs
200 Laurel Avenue South 200 Laurel Avenue South
Middletown,, NJ 07748 Middletown,, NJ 07748
USA USA
Phone: +1 732 420 1571 Phone: +1 732 420 1571
Fax: +1 732 368 1192 Fax: +1 732 368 1192
Email: acmorton@att.com Email: acmorton@att.com
URI: http://home.comcast.net/~acmacm/ URI: http://home.comcast.net/~acmacm/
Steven Van den Berghe (editor) Steven Van den Berghe (editor)
Ghent University - IBBT Alcatel-Lucent
G. Crommenlaan 8 bus 201 Copernicuslaan 50
Gent 9050 Antwerp 2018
Belgium Belgium
Phone: +32 9 331 49 73 Phone: +32 3 240 3983
Email: steven.vandenberghe@intec.ugent.be Email: steven.van_den_berghe@alcatel-lucent.com
URI: http://www.ibcn.intec.ugent.be URI:
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