draft-ietf-ippm-spatial-composition-06.txt   draft-ietf-ippm-spatial-composition-07.txt 
Network Working Group A. Morton Network Working Group A. Morton
Internet-Draft AT&T Labs Internet-Draft AT&T Labs
Intended status: Standards Track E. Stephan Intended status: Standards Track E. Stephan
Expires: August 27, 2008 France Telecom Division R&D Expires: January 14, 2009 France Telecom Division R&D
February 24, 2008 July 13, 2008
Spatial Composition of Metrics Spatial Composition of Metrics
draft-ietf-ippm-spatial-composition-06 draft-ietf-ippm-spatial-composition-07
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on August 27, 2008. This Internet-Draft will expire on January 14, 2009.
Copyright Notice
Copyright (C) The IETF Trust (2008).
Abstract Abstract
This memo utilizes IPPM metrics that are applicable to both complete This memo utilizes IPPM metrics that are applicable to both complete
paths and sub-paths, and defines relationships to compose a complete paths and sub-paths, and defines relationships to compose a complete
path metric from the sub-path metrics with some accuracy w.r.t. the path metric from the sub-path metrics with some accuracy w.r.t. the
actual metrics. This is called Spatial Composition in RFC 2330. The actual metrics. This is called Spatial Composition in RFC 2330. The
memo refers to the Framework for Metric Composition, and provides memo refers to the Framework for Metric Composition, and provides
background and motivation for combining metrics to derive others. background and motivation for combining metrics to derive others.
The descriptions of several composed metrics and statistics follow. The descriptions of several composed metrics and statistics follow.
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4. Common Specifications for Composed Metrics . . . . . . . . . . 7 4. Common Specifications for Composed Metrics . . . . . . . . . . 7
4.1. Name: Type-P . . . . . . . . . . . . . . . . . . . . . . . 7 4.1. Name: Type-P . . . . . . . . . . . . . . . . . . . . . . . 7
4.1.1. Metric Parameters . . . . . . . . . . . . . . . . . . 7 4.1.1. Metric Parameters . . . . . . . . . . . . . . . . . . 7
4.1.2. Definition and Metric Units . . . . . . . . . . . . . 8 4.1.2. Definition and Metric Units . . . . . . . . . . . . . 8
4.1.3. Discussion and other details . . . . . . . . . . . . . 8 4.1.3. Discussion and other details . . . . . . . . . . . . . 8
4.1.4. Statistic: . . . . . . . . . . . . . . . . . . . . . . 8 4.1.4. Statistic: . . . . . . . . . . . . . . . . . . . . . . 8
4.1.5. Composition Function . . . . . . . . . . . . . . . . . 8 4.1.5. Composition Function . . . . . . . . . . . . . . . . . 8
4.1.6. Statement of Conjecture and Assumptions . . . . . . . 8 4.1.6. Statement of Conjecture and Assumptions . . . . . . . 8
4.1.7. Justification of the Composition Function . . . . . . 8 4.1.7. Justification of the Composition Function . . . . . . 8
4.1.8. Sources of Deviation from the Ground Truth . . . . . . 9 4.1.8. Sources of Deviation from the Ground Truth . . . . . . 9
4.1.9. Specific cases where the conjecture might fail . . . . 9 4.1.9. Specific cases where the conjecture might fail . . . . 10
4.1.10. Application of Measurement Methodology . . . . . . . . 9 4.1.10. Application of Measurement Methodology . . . . . . . . 10
5. One-way Delay Composed Metrics and Statistics . . . . . . . . 10 5. One-way Delay Composed Metrics and Statistics . . . . . . . . 10
5.1. Name: 5.1. Name:
Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream . . . 10 Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream . . . 10
5.1.1. Metric Parameters . . . . . . . . . . . . . . . . . . 10 5.1.1. Metric Parameters . . . . . . . . . . . . . . . . . . 10
5.1.2. Definition and Metric Units . . . . . . . . . . . . . 10 5.1.2. Definition and Metric Units . . . . . . . . . . . . . 11
5.1.3. Discussion and other details . . . . . . . . . . . . . 10 5.1.3. Discussion and other details . . . . . . . . . . . . . 11
5.2. Name: Type-P-Finite-Composite-One-way-Delay-Mean . . . . . 11 5.2. Name: Type-P-Finite-Composite-One-way-Delay-Mean . . . . . 11
5.2.1. Metric Parameters . . . . . . . . . . . . . . . . . . 11 5.2.1. Metric Parameters . . . . . . . . . . . . . . . . . . 11
5.2.2. Definition and Metric Units of the Mean Statistic . . 11 5.2.2. Definition and Metric Units of the Mean Statistic . . 11
5.2.3. Discussion and other details . . . . . . . . . . . . . 11 5.2.3. Discussion and other details . . . . . . . . . . . . . 12
5.2.4. Composition Function: Sum of Means . . . . . . . . . . 11 5.2.4. Composition Function: Sum of Means . . . . . . . . . . 12
5.2.5. Statement of Conjecture and Assumptions . . . . . . . 12 5.2.5. Statement of Conjecture and Assumptions . . . . . . . 12
5.2.6. Justification of the Composition Function . . . . . . 12 5.2.6. Justification of the Composition Function . . . . . . 13
5.2.7. Sources of Deviation from the Ground Truth . . . . . . 12 5.2.7. Sources of Deviation from the Ground Truth . . . . . . 13
5.2.8. Specific cases where the conjecture might fail . . . . 12 5.2.8. Specific cases where the conjecture might fail . . . . 13
5.2.9. Application of Measurement Methodology . . . . . . . . 12 5.2.9. Application of Measurement Methodology . . . . . . . . 13
5.3. Name: Type-P-Finite-Composite-One-way-Delay-Minimum . . . 12 5.3. Name: Type-P-Finite-Composite-One-way-Delay-Minimum . . . 13
5.3.1. Metric Parameters . . . . . . . . . . . . . . . . . . 13 5.3.1. Metric Parameters . . . . . . . . . . . . . . . . . . 13
5.3.2. Definition and Metric Units of the Mean Statistic . . 13 5.3.2. Definition and Metric Units of the Mean Statistic . . 13
5.3.3. Discussion and other details . . . . . . . . . . . . . 13 5.3.3. Discussion and other details . . . . . . . . . . . . . 14
5.3.4. Composition Function: Sum of Means . . . . . . . . . . 13 5.3.4. Composition Function: Sum of Means . . . . . . . . . . 14
5.3.5. Statement of Conjecture and Assumptions . . . . . . . 14 5.3.5. Statement of Conjecture and Assumptions . . . . . . . 14
5.3.6. Justification of the Composition Function . . . . . . 14 5.3.6. Justification of the Composition Function . . . . . . 14
5.3.7. Sources of Deviation from the Ground Truth . . . . . . 14 5.3.7. Sources of Deviation from the Ground Truth . . . . . . 14
5.3.8. Specific cases where the conjecture might fail . . . . 14 5.3.8. Specific cases where the conjecture might fail . . . . 15
5.3.9. Application of Measurement Methodology . . . . . . . . 14 5.3.9. Application of Measurement Methodology . . . . . . . . 15
6. Loss Metrics and Statistics . . . . . . . . . . . . . . . . . 14 6. Loss Metrics and Statistics . . . . . . . . . . . . . . . . . 15
6.1. Type-P-Composite-One-way-Packet-Loss-Empirical-Probability 14 6.1. Type-P-Composite-One-way-Packet-Loss-Empirical-Probability 15
6.1.1. Metric Parameters: . . . . . . . . . . . . . . . . . . 14 6.1.1. Metric Parameters: . . . . . . . . . . . . . . . . . . 15
6.1.2. Definition and Metric Units . . . . . . . . . . . . . 14 6.1.2. Definition and Metric Units . . . . . . . . . . . . . 15
6.1.3. Discussion and other details . . . . . . . . . . . . . 15 6.1.3. Discussion and other details . . . . . . . . . . . . . 15
6.1.4. Statistic: 6.1.4. Statistic:
Type-P-One-way-Packet-Loss-Empirical-Probability . . . 15 Type-P-One-way-Packet-Loss-Empirical-Probability . . . 15
6.1.5. Composition Function: Composition of Empirical 6.1.5. Composition Function: Composition of Empirical
Probabilities . . . . . . . . . . . . . . . . . . . . 15 Probabilities . . . . . . . . . . . . . . . . . . . . 16
6.1.6. Statement of Conjecture and Assumptions . . . . . . . 15 6.1.6. Statement of Conjecture and Assumptions . . . . . . . 16
6.1.7. Justification of the Composition Function . . . . . . 16 6.1.7. Justification of the Composition Function . . . . . . 16
6.1.8. Sources of Deviation from the Ground Truth . . . . . . 16 6.1.8. Sources of Deviation from the Ground Truth . . . . . . 16
6.1.9. Specific cases where the conjecture might fail . . . . 16 6.1.9. Specific cases where the conjecture might fail . . . . 16
6.1.10. Application of Measurement Methodology . . . . . . . . 16 6.1.10. Application of Measurement Methodology . . . . . . . . 17
7. Delay Variation Metrics and Statistics . . . . . . . . . . . . 16 7. Delay Variation Metrics and Statistics . . . . . . . . . . . . 17
7.1. Name: Type-P-One-way-pdv-refmin-Poisson/Periodic-Stream . 16 7.1. Name: Type-P-One-way-pdv-refmin-Poisson/Periodic-Stream . 17
7.1.1. Metric Parameters: . . . . . . . . . . . . . . . . . . 16 7.1.1. Metric Parameters: . . . . . . . . . . . . . . . . . . 17
7.1.2. Definition and Metric Units . . . . . . . . . . . . . 17 7.1.2. Definition and Metric Units . . . . . . . . . . . . . 18
7.1.3. Discussion and other details . . . . . . . . . . . . . 17 7.1.3. Discussion and other details . . . . . . . . . . . . . 18
7.1.4. Statistics: Mean, Variance, Skewness, Quanitle . . . . 18 7.1.4. Statistics: Mean, Variance, Skewness, Quanitle . . . . 18
7.1.5. Composition Functions: . . . . . . . . . . . . . . . . 18 7.1.5. Composition Functions: . . . . . . . . . . . . . . . . 19
7.1.6. Statement of Conjecture and Assumptions . . . . . . . 19 7.1.6. Statement of Conjecture and Assumptions . . . . . . . 20
7.1.7. Justification of the Composition Function . . . . . . 20 7.1.7. Justification of the Composition Function . . . . . . 20
7.1.8. Sources of Deviation from the Ground Truth . . . . . . 20 7.1.8. Sources of Deviation from the Ground Truth . . . . . . 21
7.1.9. Specific cases where the conjecture might fail . . . . 20 7.1.9. Specific cases where the conjecture might fail . . . . 21
7.1.10. Application of Measurement Methodology . . . . . . . . 20 7.1.10. Application of Measurement Methodology . . . . . . . . 21
8. Security Considerations . . . . . . . . . . . . . . . . . . . 20 8. Security Considerations . . . . . . . . . . . . . . . . . . . 21
8.1. Denial of Service Attacks . . . . . . . . . . . . . . . . 20 8.1. Denial of Service Attacks . . . . . . . . . . . . . . . . 21
8.2. User Data Confidentiality . . . . . . . . . . . . . . . . 21 8.2. User Data Confidentiality . . . . . . . . . . . . . . . . 21
8.3. Interference with the metrics . . . . . . . . . . . . . . 21 8.3. Interference with the metrics . . . . . . . . . . . . . . 22
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22
10. Issues (Open and Closed) . . . . . . . . . . . . . . . . . . . 21 10. Acknowlegements . . . . . . . . . . . . . . . . . . . . . . . 22
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 22 11. Issues (Open and Closed) . . . . . . . . . . . . . . . . . . . 22
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 23 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 24
12.1. Normative References . . . . . . . . . . . . . . . . . . . 23 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24
12.2. Informative References . . . . . . . . . . . . . . . . . . 23 13.1. Normative References . . . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23 13.2. Informative References . . . . . . . . . . . . . . . . . . 24
Intellectual Property and Copyright Statements . . . . . . . . . . 25 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 25
Intellectual Property and Copyright Statements . . . . . . . . . . 26
1. Contributors 1. Contributors
Thus far, the following people have contributed useful ideas, Thus far, the following people have contributed useful ideas,
suggestions, or the text of sections that have been incorporated into suggestions, or the text of sections that have been incorporated into
this memo: this memo:
- Phil Chimento <vze275m9@verizon.net> - Phil Chimento <vze275m9@verizon.net>
- Reza Fardid <RFardid@Covad.COM> - Reza Fardid <RFardid@Covad.COM>
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size/rate, while a larger sample size/rate may be used on other sub- size/rate, while a larger sample size/rate may be used on other sub-
paths. paths.
Also, since measurement operations have a real monetary cost, there Also, since measurement operations have a real monetary cost, there
is value in re-using measurements where they are applicable, rather is value in re-using measurements where they are applicable, rather
than launching new measurements for every possible source-destination than launching new measurements for every possible source-destination
pair. pair.
4.1.8. Sources of Deviation from the Ground Truth 4.1.8. Sources of Deviation from the Ground Truth
4.1.8.1. Sub-path List Differs from Complete Path
The measurement packets, each having source and destination addresses The measurement packets, each having source and destination addresses
intended for collection at edges of the sub-path, may take a intended for collection at edges of the sub-path, may take a
different specific path through the network equipment and parallel different specific path through the network equipment and parallel
links when compared to packets with the source and destination links when compared to packets with the source and destination
addresses of the complete path. Therefore, the composition of sub- addresses of the complete path. Therefore, the performance estimated
path measurements may differ from the performance experienced by from the composition of sub-path measurements may differ from the
packets on the complete path. Multiple measurements employing performance experienced by packets on the complete path. Multiple
sufficient sub-path address pairs might produce bounds on the extent measurements employing sufficient sub-path address pairs might
of this error. produce bounds on the extent of this error.
4.1.8.2. Sub-path Contains Extra Network Elements
Related to the case of an alternate path described above is the case Related to the case of an alternate path described above is the case
where elements in the measured path are unique to measurement system where elements in the measured path are unique to measurement system
connectivity. For example, a measurement system may use a dedicated connectivity. For example, a measurement system may use a dedicated
link to a LAN switch, and packets on the complete path do not link to a LAN switch, and packets on the complete path do not
traverse that link. The performance of such a dedicated link would traverse that link. The performance of such a dedicated link would
be measured continuously, and its contribution to the sub-path be measured continuously, and its contribution to the sub-path
metrics SHOULD be minimized as a source of error. metrics SHOULD be minimized as a source of error.
others??? 4.1.8.3. Sub-paths Have Incomplete Coverage
Measurements of sub-path performance may not cover all the network
elements on the complete path. For example, the network exchange
points might be excluded unless a cooperative measurement is
conducted. In this example, test packets on the previous sub-path
are received just before the exchange point and test packets on the
next sub-path are injected just after the same exchange point.
Clearly, the set of sub-path measurements SHOULD cover all critical
network elements in the complete path.
4.1.8.4. Absence of route
********************
Note: this section may be expressing the point of 4.1.8.1 in
different words - its status is TBD.
********************
Sub-path destination addresses and complete path addresses do not
belong to the same network. Therefore routes selected to reach each
sub-path destinations differ from the route that would be selected to
reach the destination address of the complete path. Consequently
spatial composition may produce finite estimation of a ground true
metric between a source Src and a destination Dst when the route
between Src and Dst is undefined.
4.1.9. Specific cases where the conjecture might fail 4.1.9. Specific cases where the conjecture might fail
This section is unique for each metric. This section is unique for each metric (see the metric-specific
sections).
4.1.10. Application of Measurement Methodology 4.1.10. Application of Measurement Methodology
The methodology: The methodology:
SHOULD use similar packets sent and collected separately in each sub- SHOULD use similar packets sent and collected separately in each sub-
path. path.
Allows a degree of flexibility regarding test stream generation Allows a degree of flexibility regarding test stream generation
(e.g., active or passive methods can produce an equivalent result, (e.g., active or passive methods can produce an equivalent result,
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To discourage the kind of interference mentioned above, packet To discourage the kind of interference mentioned above, packet
interference checks, such as cryptographic hash, may be used. interference checks, such as cryptographic hash, may be used.
9. IANA Considerations 9. IANA Considerations
Metrics defined in this memo will be registered in the IANA IPPM Metrics defined in this memo will be registered in the IANA IPPM
METRICS REGISTRY as described in initial version of the registry METRICS REGISTRY as described in initial version of the registry
[RFC4148]. [RFC4148].
10. Issues (Open and Closed) 10. Acknowlegements
A long time ago, in a galaxy far, far away (Minneapolis), Will Leland
suggested the simple and elegant Type-P-Finite-One-way-Delay concept.
Thanks Will.
11. Issues (Open and Closed)
>>>>>>>>>>>>Issue:
Is Section 4.1.8.4 really describing a new error case, about
Alternate Routing? Or does Section 4.1.8.1 on sub-path differences
cover it all?
>>>>>>>>>>>>Issue: >>>>>>>>>>>>Issue:
What is the relationship between the decomposition and composition What is the relationship between the decomposition and composition
metrics? Should we put both kinds in one draft to make up a metrics? Should we put both kinds in one draft to make up a
framework? The motivation of decomposition is as follows: framework? The motivation of decomposition is as follows:
The One-way measurement can provide result to show what the network The One-way measurement can provide result to show what the network
performance between two end hosts is and whether it meets operator performance between two end hosts is and whether it meets operator
expectations or not. It cannot provide further information to expectations or not. It cannot provide further information to
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>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Issue >>>>>>>>>>>>>>>>> Issue
Can we introduce multicast metrics here, without causing too much Can we introduce multicast metrics here, without causing too much
confusion? Should the multicast version of this draft wait until the confusion? Should the multicast version of this draft wait until the
Unicast concepts are stable (or maybe appear in a separate draft)? Unicast concepts are stable (or maybe appear in a separate draft)?
>>>>>>>>>>>>>>>>RESOLUTION: No and Yes. >>>>>>>>>>>>>>>>RESOLUTION: No and Yes.
11. Acknowledgements 12. Acknowledgements
12. References 13. References
12.1. Normative References 13.1. Normative References
[I-D.ietf-ippm-framework-compagg] [I-D.ietf-ippm-framework-compagg]
Morton, A., "Framework for Metric Composition", Morton, A., "Framework for Metric Composition",
draft-ietf-ippm-framework-compagg-06 (work in progress), draft-ietf-ippm-framework-compagg-06 (work in progress),
February 2008. February 2008.
[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,
skipping to change at page 23, line 32 skipping to change at page 24, line 36
[RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way [RFC2680] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
Packet Loss Metric for IPPM", RFC 2680, September 1999. Packet Loss Metric for IPPM", RFC 2680, September 1999.
[RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation [RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation
Metric for IP Performance Metrics (IPPM)", RFC 3393, Metric for IP Performance Metrics (IPPM)", RFC 3393,
November 2002. November 2002.
[RFC4148] Stephan, E., "IP Performance Metrics (IPPM) Metrics [RFC4148] Stephan, E., "IP Performance Metrics (IPPM) Metrics
Registry", BCP 108, RFC 4148, August 2005. Registry", BCP 108, RFC 4148, August 2005.
12.2. Informative References 13.2. Informative References
[I-D.ietf-ippm-multimetrics] [I-D.ietf-ippm-multimetrics]
Stephan, E., Liang, L., and A. Morton, "IP Performance Stephan, E., Liang, L., and A. Morton, "IP Performance
Metrics (IPPM) for spatial and multicast", Metrics (IPPM) for spatial and multicast",
draft-ietf-ippm-multimetrics-06 (work in progress), draft-ietf-ippm-multimetrics-07 (work in progress),
February 2008. June 2008.
[Y.1540] ITU-T Recommendation Y.1540, "Internet protocol data [Y.1540] ITU-T Recommendation Y.1540, "Internet protocol data
communication service - IP packet transfer and communication service - IP packet transfer and
availability performance parameters", December 2002. availability performance parameters", December 2002.
[Y.1541] ITU-T Recommendation Y.1541, "Network Performance [Y.1541] ITU-T Recommendation Y.1541, "Network Performance
Objectives for IP-based Services", February 2006. Objectives for IP-based Services", February 2006.
Authors' Addresses Authors' Addresses
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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/
Emile Stephan Stephan Emile
France Telecom Division R&D France Telecom Division R&D
2 avenue Pierre Marzin 2 avenue Pierre Marzin
Lannion, F-22307 Lannion, F-22307
France France
Phone: Phone:
Fax: +33 2 96 05 18 52 Fax: +33 2 96 05 18 52
Email: emile.stephan@orange-ftgroup.com Email: emile.stephan@orange-ftgroup.com
URI: URI:
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attempt made to obtain a general license or permission for the use of attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at this standard. Please address the information to the IETF at
ietf-ipr@ietf.org. ietf-ipr@ietf.org.
Acknowledgment
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
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