draft-ietf-ippm-spatial-composition-02.txt | draft-ietf-ippm-spatial-composition-03.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: April 25, 2007 France Telecom Division R&D | Expires: September 16, 2007 France Telecom Division R&D | |||

October 22, 2006 | March 15, 2007 | |||

Spatial Composition of Metrics | Spatial Composition of Metrics | |||

draft-ietf-ippm-spatial-composition-02 | draft-ietf-ippm-spatial-composition-03 | |||

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 | |||

Task Force (IETF), its areas, and its working groups. Note that | Task Force (IETF), its areas, and its working groups. Note that | |||

skipping to change at page 1, line 35 | skipping to change at page 1, line 35 | |||

and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||

time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||

material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||

The list of current Internet-Drafts can be accessed at | The list of current Internet-Drafts can be accessed at | |||

http://www.ietf.org/ietf/1id-abstracts.txt. | http://www.ietf.org/ietf/1id-abstracts.txt. | |||

The list of Internet-Draft Shadow Directories can be accessed at | The list of Internet-Draft Shadow Directories can be accessed at | |||

http://www.ietf.org/shadow.html. | http://www.ietf.org/shadow.html. | |||

This Internet-Draft will expire on April 25, 2007. | This Internet-Draft will expire on September 16, 2007. | |||

Copyright Notice | Copyright Notice | |||

Copyright (C) The Internet Society (2006). | Copyright (C) The IETF Trust (2007). | |||

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. | |||

skipping to change at page 2, line 22 | skipping to change at page 2, line 22 | |||

equal to" and ">=" as "greater than or equal to". | equal to" and ">=" as "greater than or equal to". | |||

Table of Contents | Table of Contents | |||

1. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 1. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 4 | |||

2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 | |||

2.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 5 | 2.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||

3. Scope and Application . . . . . . . . . . . . . . . . . . . . 5 | 3. Scope and Application . . . . . . . . . . . . . . . . . . . . 5 | |||

3.1. Scope of work . . . . . . . . . . . . . . . . . . . . . . 6 | 3.1. Scope of work . . . . . . . . . . . . . . . . . . . . . . 6 | |||

3.2. Application . . . . . . . . . . . . . . . . . . . . . . . 6 | 3.2. Application . . . . . . . . . . . . . . . . . . . . . . . 6 | |||

4. One-way Delay Composed Metrics and Statistics . . . . . . . . 7 | 3.3. Incomplete Information . . . . . . . . . . . . . . . . . . 7 | |||

4.1. Name: | 4. Common Specifications for Composed Metrics . . . . . . . . . . 7 | |||

Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream . . . 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 . . . . . . . . . . . . . 7 | 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. Mean Statistic . . . . . . . . . . . . . . . . . . . . 8 | 4.1.4. Statistic: . . . . . . . . . . . . . . . . . . . . . . 8 | |||

4.1.5. Composition Function: Sum of Means . . . . . . . . . . 8 | 4.1.5. Composition Function: Sum of Means . . . . . . . . . . 8 | |||

4.1.6. Statement of Conjecture . . . . . . . . . . . . . . . 9 | 4.1.6. Statement of Conjecture . . . . . . . . . . . . . . . 8 | |||

4.1.7. Justification of the Composition Function . . . . . . 9 | 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 . . . . 9 | |||

4.1.10. Application of Measurement Methodology . . . . . . . . 10 | 4.1.10. Application of Measurement Methodology . . . . . . . . 9 | |||

5. Loss Metrics and Statistics . . . . . . . . . . . . . . . . . 10 | 5. One-way Delay Composed Metrics and Statistics . . . . . . . . 9 | |||

5.1. Name: | 5.1. Name: | |||

Type-P-One-way-Packet-Loss-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 . . . . . . . . . . . . . 10 | |||

5.1.3. Discussion and other details . . . . . . . . . . . . . 11 | 5.1.3. Discussion and other details . . . . . . . . . . . . . 10 | |||

5.1.4. Statistic: | 5.1.4. Mean Statistic . . . . . . . . . . . . . . . . . . . . 10 | |||

Type-P-One-way-Packet-Loss-Empirical-Probability . . . 11 | 5.1.5. Composition Function: Sum of Means . . . . . . . . . . 11 | |||

5.1.5. Composition Function: Composition of Empirical | ||||

Probabilities . . . . . . . . . . . . . . . . . . . . 11 | ||||

5.1.6. Statement of Conjecture . . . . . . . . . . . . . . . 11 | 5.1.6. Statement of Conjecture . . . . . . . . . . . . . . . 11 | |||

5.1.7. Justification of the Composition Function . . . . . . 11 | 5.1.7. Justification of the Composition Function . . . . . . 11 | |||

5.1.8. Sources of Deviation from the Ground Truth . . . . . . 12 | 5.1.8. Sources of Deviation from the Ground Truth . . . . . . 11 | |||

5.1.9. Specific cases where the conjecture might fail . . . . 12 | 5.1.9. Specific cases where the conjecture might fail . . . . 11 | |||

5.1.10. Application of Measurement Methodology . . . . . . . . 12 | 5.1.10. Application of Measurement Methodology . . . . . . . . 12 | |||

6. Delay Variation Metrics and Statistics . . . . . . . . . . . . 13 | 6. Loss Metrics and Statistics . . . . . . . . . . . . . . . . . 12 | |||

6.1. Name: | 6.1. Name: | |||

Type-P-One-way-Packet-Loss-Poisson/Periodic-Stream . . . . 12 | ||||

Type-P-One-way-ipdv-refmin-Poisson/Periodic-Stream . . . . 13 | 6.1.1. Metric Parameters: . . . . . . . . . . . . . . . . . . 12 | |||

6.1.1. Metric Parameters: . . . . . . . . . . . . . . . . . . 13 | 6.1.2. Definition and Metric Units . . . . . . . . . . . . . 12 | |||

6.1.2. Definition and Metric Units . . . . . . . . . . . . . 14 | 6.1.3. Discussion and other details . . . . . . . . . . . . . 12 | |||

6.1.3. Discussion and other details . . . . . . . . . . . . . 14 | 6.1.4. Statistic: | |||

6.1.4. Statistics: Mean, Variance, Skewness, Quanitle . . . . 14 | Type-P-One-way-Packet-Loss-Empirical-Probability . . . 12 | |||

6.1.5. Composition Functions: . . . . . . . . . . . . . . . . 15 | 6.1.5. Composition Function: Composition of Empirical | |||

6.1.6. Statement of Conjecture . . . . . . . . . . . . . . . 15 | Probabilities . . . . . . . . . . . . . . . . . . . . 13 | |||

6.1.7. Justification of the Composition Function . . . . . . 15 | 6.1.6. Statement of Conjecture . . . . . . . . . . . . . . . 13 | |||

6.1.8. Sources of Deviation from the Ground Truth . . . . . . 15 | 6.1.7. Justification of the Composition Function . . . . . . 13 | |||

6.1.9. Specific cases where the conjecture might fail . . . . 15 | 6.1.8. Sources of Deviation from the Ground Truth . . . . . . 13 | |||

6.1.10. Application of Measurement Methodology . . . . . . . . 15 | 6.1.9. Specific cases where the conjecture might fail . . . . 13 | |||

7. Other Metrics and Statistics: One-way Combined Metric . . . . 16 | 6.1.10. Application of Measurement Methodology . . . . . . . . 14 | |||

8. Security Considerations . . . . . . . . . . . . . . . . . . . 16 | 7. Delay Variation Metrics and Statistics . . . . . . . . . . . . 14 | |||

8.1. Denial of Service Attacks . . . . . . . . . . . . . . . . 16 | 7.1. Name: | |||

8.2. User Data Confidentiality . . . . . . . . . . . . . . . . 16 | Type-P-One-way-ipdv-refmin-Poisson/Periodic-Stream . . . . 14 | |||

8.3. Interference with the metrics . . . . . . . . . . . . . . 16 | 7.1.1. Metric Parameters: . . . . . . . . . . . . . . . . . . 14 | |||

9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 | 7.1.2. Definition and Metric Units . . . . . . . . . . . . . 15 | |||

10. Issues (Open and Closed) . . . . . . . . . . . . . . . . . . . 17 | 7.1.3. Discussion and other details . . . . . . . . . . . . . 15 | |||

11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18 | 7.1.4. Statistics: Mean, Variance, Skewness, Quanitle . . . . 15 | |||

12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 | 7.1.5. Composition Functions: . . . . . . . . . . . . . . . . 16 | |||

12.1. Normative References . . . . . . . . . . . . . . . . . . . 18 | 7.1.6. Statement of Conjecture . . . . . . . . . . . . . . . 17 | |||

12.2. Informative References . . . . . . . . . . . . . . . . . . 19 | 7.1.7. Justification of the Composition Function . . . . . . 17 | |||

Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19 | 7.1.8. Sources of Deviation from the Ground Truth . . . . . . 17 | |||

Intellectual Property and Copyright Statements . . . . . . . . . . 20 | 7.1.9. Specific cases where the conjecture might fail . . . . 18 | |||

7.1.10. Application of Measurement Methodology . . . . . . . . 18 | ||||

8. Security Considerations . . . . . . . . . . . . . . . . . . . 18 | ||||

8.1. Denial of Service Attacks . . . . . . . . . . . . . . . . 18 | ||||

8.2. User Data Confidentiality . . . . . . . . . . . . . . . . 18 | ||||

8.3. Interference with the metrics . . . . . . . . . . . . . . 18 | ||||

9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 | ||||

10. Issues (Open and Closed) . . . . . . . . . . . . . . . . . . . 19 | ||||

11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 20 | ||||

12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20 | ||||

12.1. Normative References . . . . . . . . . . . . . . . . . . . 20 | ||||

12.2. Informative References . . . . . . . . . . . . . . . . . . 21 | ||||

Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21 | ||||

Intellectual Property and Copyright Statements . . . . . . . . . . 23 | ||||

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> | |||

skipping to change at page 4, line 25 | skipping to change at page 4, line 25 | |||

- Roman Krzanowski <roman.krzanowski@verizon.com> | - Roman Krzanowski <roman.krzanowski@verizon.com> | |||

- Maurizio Molina <maurizio.molina@dante.org.uk> | - Maurizio Molina <maurizio.molina@dante.org.uk> | |||

- Al Morton <acmorton@att.com> | - Al Morton <acmorton@att.com> | |||

- Emile Stephan <emile.stephan@francetelecom.com> | - Emile Stephan <emile.stephan@francetelecom.com> | |||

- Lei Liang <L.Liang@surrey.ac.uk> | - Lei Liang <L.Liang@surrey.ac.uk> | |||

- Dave Hoeflin <dhoeflin@att.com> | ||||

2. Introduction | 2. Introduction | |||

The IPPM framework [RFC2330] describes two forms of metric | The IPPM framework [RFC2330] describes two forms of metric | |||

composition, spatial and temporal. The new composition framework | composition, spatial and temporal. The new composition framework | |||

[I-D.ietf-ippm-framework-compagg] expands and further qualifies these | [I-D.ietf-ippm-framework-compagg] expands and further qualifies these | |||

original forms into three categories. This memo describes Spatial | original forms into three categories. This memo describes Spatial | |||

Composition, one of the categories of metrics under the umbrella of | Composition, one of the categories of metrics under the umbrella of | |||

the composition framework. | the composition framework. | |||

Spatial composition encompasses the definition of performance metrics | Spatial composition encompasses the definition of performance metrics | |||

skipping to change at page 7, line 5 | skipping to change at page 7, line 5 | |||

operator's domain, or is applicable to Inter-domain composition. | operator's domain, or is applicable to Inter-domain composition. | |||

Requires synchronized measurement time intervals in all sub-paths, or | Requires synchronized measurement time intervals in all sub-paths, or | |||

largely overlapping, or no timing requirements. | largely overlapping, or no timing requirements. | |||

Requires assumption of sub-path independence w.r.t. the metric being | Requires assumption of sub-path independence w.r.t. the metric being | |||

defined/composed, or other assumptions. | defined/composed, or other assumptions. | |||

Has known sources of inaccuracy/error, and identifies the sources. | Has known sources of inaccuracy/error, and identifies the sources. | |||

4. One-way Delay Composed Metrics and Statistics | 3.3. Incomplete Information | |||

4.1. Name: Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream | In practice, when measurements cannot be initiated on a sub-path (and | |||

perhaps the measurement system gives up during the test interval), | ||||

then there will not be a value for the sub-path reported, and the | ||||

result SHOULD be recorded as "undefined". This case should be | ||||

distinguished from the case where the measurement system continued to | ||||

send packets throughout the test interval, but all were declared | ||||

lost. | ||||

This metric is a necessary element of Delay Composition metrics, and | When a composed metric requires measurements from sub paths A, B, and | |||

its definition does not formally exist elsewhere in IPPM literature. | C, and one or more of the sub-path results are undefined, then the | |||

composed metric SHOULD also be recorded as undefined. | ||||

4.1.1. Metric Parameters: | 4. Common Specifications for Composed Metrics | |||

o Src, the IP address of a host + Dst, the IP address of a host | To reduce the redundant information presented in the detailed metrics | |||

sections that follow, this section presents the specifications that | ||||

are common to two or more metrics. The section is organized using | ||||

the same subsections as the individual metrics, to simplify | ||||

comparisons. | ||||

4.1. Name: Type-P | ||||

All metrics use the Type-P convention as described in [RFC2330]. The | ||||

rest of the name is unique to each metric. | ||||

4.1.1. Metric Parameters | ||||

o Src, the IP address of a host | ||||

o Dst, the IP address of a host | ||||

o T, a time (start of test interval) | o T, a time (start of test interval) | |||

o Tf, a time (end of test interval) | o Tf, a time (end of test interval) | |||

o lambda, a rate in reciprocal seconds (for Poisson Streams) | o lambda, a rate in reciprocal seconds (for Poisson Streams) | |||

o incT, the nominal duration of inter-packet interval, first bit to | o incT, the nominal duration of inter-packet interval, first bit to | |||

first bit (for Periodic Streams) | first bit (for Periodic Streams) | |||

skipping to change at page 7, line 39 | skipping to change at page 8, line 14 | |||

o TstampSrc, the wire time of the packet as measured at MP(Src) | o TstampSrc, the wire time of the packet as measured at MP(Src) | |||

o TstampDst, the wire time of the packet as measured at MP(Dst), | o TstampDst, the wire time of the packet as measured at MP(Dst), | |||

assigned to packets that arrive within a "reasonable" time. | assigned to packets that arrive within a "reasonable" time. | |||

o Tmax, a maximum waiting time for packets at the destination, set | o Tmax, a maximum waiting time for packets at the destination, set | |||

sufficiently long to disambiguate packets with long delays from | sufficiently long to disambiguate packets with long delays from | |||

packets that are discarded (lost), thus the distribution of delay | packets that are discarded (lost), thus the distribution of delay | |||

is not truncated. | is not truncated. | |||

o M, the total number of packets sent between T0 and Tf | ||||

o N, the total number of packets received at Dst (sent between T0 | ||||

and Tf) | ||||

o S, the number of sub-paths involved in the complete Src-Dst path | ||||

4.1.2. Definition and Metric Units | 4.1.2. Definition and Metric Units | |||

This section is unique for every metric. | ||||

4.1.3. Discussion and other details | ||||

This section is unique for every metric. | ||||

4.1.4. Statistic: | ||||

This section is unique for every metric. | ||||

4.1.5. Composition Function: Sum of Means | ||||

This section is unique for every metric. | ||||

4.1.6. Statement of Conjecture | ||||

This section is unique for each metric. | ||||

4.1.7. Justification of the Composition Function | ||||

It is sometimes impractical to conduct active measurements between | ||||

every Src-Dst pair. For example, it may not be possible to collect | ||||

the desired sample size in each test interval when access link speed | ||||

is limited, because of the potential for measurement traffic to | ||||

degrade the user traffic performance. The conditions on a low-speed | ||||

access link may be understood well-enough to permit use of a small | ||||

sample size/rate, while a larger sample size/rate may be used on | ||||

other sub-paths. | ||||

Also, since measurement operations have a real monetary cost, there | ||||

is value in re-using measurements where they are applicable, rather | ||||

than launching new measurements for every possible source-destination | ||||

pair. | ||||

4.1.8. Sources of Deviation from the Ground Truth | ||||

The measurement packets, each having source and destination addresses | ||||

intended for collection at edges of the sub-path, may take a | ||||

different specific path through the network equipment and parallel | ||||

exchanges than packets with the source and destination addresses of | ||||

the complete path. Therefore, the sub-path measurements may differ | ||||

from the performance experienced by packets on the complete path. | ||||

Multiple measurements employing sufficient sub-path address pairs | ||||

might produce bounds on the extent of this error. | ||||

others... | ||||

4.1.9. Specific cases where the conjecture might fail | ||||

This section is unique for each metric. | ||||

4.1.10. Application of Measurement Methodology | ||||

The methodology: | ||||

SHOULD use similar packets sent and collected separately in each sub- | ||||

path. | ||||

Allows a degree of flexibility (e.g., active or passive methods can | ||||

produce the "same" metric, but timing and correlation of passive | ||||

measurements is much more challenging). | ||||

Poisson and/or Periodic streams are RECOMMENDED. | ||||

Applicable to both Inter-domain and Intra-domain composition. | ||||

SHOULD have synchronized measurement time intervals in all sub-paths, | ||||

but largely overlapping intervals MAY suffice. | ||||

REQUIRES assumption of sub-path independence w.r.t. the metric being | ||||

defined/composed. | ||||

5. One-way Delay Composed Metrics and Statistics | ||||

5.1. Name: Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream | ||||

This metric is a necessary element of Delay Composition metrics, and | ||||

its definition does not formally exist elsewhere in IPPM literature. | ||||

5.1.1. Metric Parameters | ||||

See the common parameters section above. | ||||

5.1.2. Definition and Metric Units | ||||

Using the parameters above, we obtain the value of Type-P-One-way- | Using the parameters above, we obtain the value of Type-P-One-way- | |||

Delay singleton as per [RFC2679]. | Delay singleton as per [RFC2679]. | |||

For each packet [i] that has a finite One-way Delay (in other words, | For each packet [i] that has a finite One-way Delay (in other words, | |||

excluding packets which have undefined one-way delay): | excluding packets which have undefined one-way delay): | |||

Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream[i] = | Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream[i] = | |||

FiniteDelay[i] = TstampDst - TstampSrc | FiniteDelay[i] = TstampDst - TstampSrc | |||

4.1.3. Discussion and other details | 5.1.3. Discussion and other details | |||

The "Type-P-Finite-One-way-Delay" metric permits calculation of the | The "Type-P-Finite-One-way-Delay" metric permits calculation of the | |||

sample mean statistic. This resolves the problem of including lost | sample mean statistic. This resolves the problem of including lost | |||

packets in the sample (whose delay is undefined), and the issue with | packets in the sample (whose delay is undefined), and the issue with | |||

the informal assignment of infinite delay to lost packets (practical | the informal assignment of infinite delay to lost packets (practical | |||

systems can only assign some very large value). | systems can only assign some very large value). | |||

The Finite-One-way-Delay approach handles the problem of lost packets | The Finite-One-way-Delay approach handles the problem of lost packets | |||

by reducing the event space. We consider conditional statistics, and | by reducing the event space. We consider conditional statistics, and | |||

estimate the mean one-way delay conditioned on the event that all | estimate the mean one-way delay conditioned on the event that all | |||

packets in the sample arrive at the destination (within the specified | packets in the sample arrive at the destination (within the specified | |||

waiting time, Tmax). This offers a way to make some valid statements | waiting time, Tmax). This offers a way to make some valid statements | |||

about one-way delay, and at the same time avoiding events with | about one-way delay, and at the same time avoiding events with | |||

undefined outcomes. This approach is derived from the treatment of | undefined outcomes. This approach is derived from the treatment of | |||

lost packets in [RFC3393], and is similar to [Y.1540] . | lost packets in [RFC3393], and is similar to [Y.1540] . | |||

4.1.4. Mean Statistic | 5.1.4. Mean Statistic | |||

We add the following parameter: | ||||

o N, the total number of packets received at Dst (sent between T0 | ||||

and Tf) | ||||

and define | ||||

We define | ||||

Type-P-Finite-One-way-Delay-Mean = | Type-P-Finite-One-way-Delay-Mean = | |||

N | N | |||

--- | --- | |||

1 \ | 1 \ | |||

- * > (FiniteDelay [i]) | - * > (FiniteDelay [i]) | |||

N / | N / | |||

--- | --- | |||

i = 1 | i = 1 | |||

where all packets i= 1 through N have finite singleton delays. | where all packets i= 1 through N have finite singleton delays. | |||

4.1.5. Composition Function: Sum of Means | 5.1.5. Composition Function: Sum of Means | |||

The Type-P-Finite--Composite-One-way-Delay-Mean, or CompMeanDelay for | The Type-P-Finite--Composite-One-way-Delay-Mean, or CompMeanDelay for | |||

the complete Source to Destination path can be calculated from sum of | the complete Source to Destination path can be calculated from sum of | |||

the Mean Delays of all its S constituent sub-paths. | the Mean Delays of all its S constituent sub-paths. | |||

o S, the number of sub-paths involved in the complete Src-Dst path. | ||||

Then the | Then the | |||

Type-P-Finite-Composite-One-way-Delay-Mean = | Type-P-Finite-Composite-One-way-Delay-Mean = | |||

CompMeanDelay = (1/S)Sum(from i=1 to S, MeanDelay[i]) | S | |||

--- | ||||

\ | ||||

CompMeanDelay = > (MeanDelay [i]) | ||||

/ | ||||

--- | ||||

i = 1 | ||||

4.1.6. Statement of Conjecture | 5.1.6. Statement of Conjecture | |||

The mean of a sufficiently large stream of packets measured on each | The mean of a sufficiently large stream of packets measured on each | |||

sub-path during the interval [T, Tf] will be representative of the | sub-path during the interval [T, Tf] will be representative of the | |||

true mean of the delay distribution (and the distributions themselves | true mean of the delay distribution (and the distributions themselves | |||

are sufficiently independent), such that the means may be added to | are sufficiently independent), such that the means may be added to | |||

produce an estimate of the complete path mean delay. | produce an estimate of the complete path mean delay. | |||

4.1.7. Justification of the Composition Function | 5.1.7. Justification of the Composition Function | |||

It is sometimes impractical to conduct active measurements between | ||||

every Src-Dst pair. For example, it may not be possible to collect | ||||

the desired sample size in each test interval when access link speed | ||||

is limited, because of the potential for measurement traffic to | ||||

degrade the user traffic performance. The conditions on a low-speed | ||||

access link may be understood well-enough to permit use of a small | ||||

sample size/rate, while a larger sample size/rate may be used on | ||||

other sub-paths. | ||||

Also, since measurement operations have a real monetary cost, there | ||||

is value in re-using measurements where they are applicable, rather | ||||

than launching new measurements for every possible source-destination | ||||

pair. | ||||

4.1.8. Sources of Deviation from the Ground Truth | See the common section. | |||

The measurement packets, each having source and destination addresses | 5.1.8. Sources of Deviation from the Ground Truth | |||

intended for collection at edges of the sub-path, may take a | ||||

different specific path through the network equipment and parallel | ||||

exchanges than packets with the source and destination addresses of | ||||

the complete path. Therefore, the sub-path measurements may differ | ||||

from the performance experienced by packets on the complete path. | ||||

Multiple measurements employing sufficient sub-path address pairs | ||||

might produce bounds on the extent of this error. | ||||

others... | See the common section. | |||

4.1.9. Specific cases where the conjecture might fail | 5.1.9. Specific cases where the conjecture might fail | |||

If any of the sub-path distributions are bimodal, then the measured | If any of the sub-path distributions are bimodal, then the measured | |||

means may not be stable, and in this case the mean will not be a | means may not be stable, and in this case the mean will not be a | |||

particularly useful statistic when describing the delay distribution | particularly useful statistic when describing the delay distribution | |||

of the complete path. | of the complete path. | |||

The mean may not be sufficiently robust statistic to produce a | The mean may not be sufficiently robust statistic to produce a | |||

reliable estimate, or to be useful even if it can be measured. | reliable estimate, or to be useful even if it can be measured. | |||

others... | others... | |||

4.1.10. Application of Measurement Methodology | 5.1.10. Application of Measurement Methodology | |||

The methodology: | ||||

SHOULD use similar packets sent and collected separately in each sub- | ||||

path. | ||||

Allows a degree of flexibility (e.g., active or passive methods can | ||||

produce the "same" metric, but timing and correlation of passive | ||||

measurements is much more challenging). | ||||

Poisson and/or Periodic streams are RECOMMENDED. | ||||

Applicable to both Inter-domain and Intra-domain composition. | ||||

SHOULD have synchronized measurement time intervals in all sub-paths, | ||||

but largely overlapping intervals MAY suffice. | ||||

REQUIRES assumption of sub-path independence w.r.t. the metric being | The requirements of the common section apply here as well. | |||

defined/composed. | ||||

5. Loss Metrics and Statistics | 6. Loss Metrics and Statistics | |||

5.1. Name: Type-P-One-way-Packet-Loss-Poisson/Periodic-Stream | 6.1. Name: Type-P-One-way-Packet-Loss-Poisson/Periodic-Stream | |||

5.1.1. Metric Parameters: | 6.1.1. Metric Parameters: | |||

Same as section 4.1.1. | Same as section 4.1.1. | |||

5.1.2. Definition and Metric Units | 6.1.2. Definition and Metric Units | |||

Using the parameters above, we obtain the value of Type-P-One-way- | Using the parameters above, we obtain the value of Type-P-One-way- | |||

Packet-Loss singleton and stream as per [RFC2680]. | Packet-Loss singleton and stream as per [RFC2680]. | |||

We obtain a sequence of pairs with elements as follows: | We obtain a sequence of pairs with elements as follows: | |||

o TstampSrc, as above | o TstampSrc, as above | |||

o L, either zero or one, where L=1 indicates loss and L=0 indicates | o L, either zero or one, where L=1 indicates loss and L=0 indicates | |||

arrival at the destination within TstampSrc + Tmax. | arrival at the destination within TstampSrc + Tmax. | |||

5.1.3. Discussion and other details | 6.1.3. Discussion and other details | |||

5.1.4. Statistic: Type-P-One-way-Packet-Loss-Empirical-Probability | ||||

Given the following stream parameter | ||||

o M, the total number of packets sent between T0 and Tf | 6.1.4. Statistic: Type-P-One-way-Packet-Loss-Empirical-Probability | |||

We can define the Empirical Probability of Loss Statistic (Ep), | Given the stream parameter M, the number of packets sent, we can | |||

consistent with Average Loss in [RFC2680], as follows: | define the Empirical Probability of Loss Statistic (Ep), consistent | |||

with Average Loss in [RFC2680], as follows: | ||||

Type-P-One-way-Packet-Loss-Empirical-Probability = | Type-P-One-way-Packet-Loss-Empirical-Probability = | |||

M | ||||

Ep = (1/M)Sum(from i=1 to M, L[i]) | --- | |||

1 \ | ||||

Ep = - * > (L[i]) | ||||

M / | ||||

--- | ||||

i = 1 | ||||

where all packets i= 1 through M have a value for L. | where all packets i= 1 through M have a value for L. | |||

5.1.5. Composition Function: Composition of Empirical Probabilities | 6.1.5. Composition Function: Composition of Empirical Probabilities | |||

The Type-P-One-way-Composite-Packet-Loss-Empirical-Probability, or | The Type-P-One-way-Composite-Packet-Loss-Empirical-Probability, or | |||

CompEp for the complete Source to Destination path can be calculated | CompEp for the complete Source to Destination path can be calculated | |||

by combining Ep of all its constituent sub-paths (Ep1, Ep2, Ep3, ... | by combining Ep of all its constituent sub-paths (Ep1, Ep2, Ep3, ... | |||

Epn) as | Epn) as | |||

Type-P-One-way-Composite-Packet-Loss-Empirical-Probability = CompEp = | Type-P-One-way-Composite-Packet-Loss-Empirical-Probability = | |||

1 - {(1 - Ep1) x (1 - Ep2) x (1 - Ep3) x ... x (1 - Epn)} | CompEp = 1 ? {(1 - Ep1) x (1 ? Ep2) x (1 ? Ep3) x ... x (1 ? Epn)} | |||

5.1.6. Statement of Conjecture | If any EpN is undefined in a particular measurement interval, | |||

possibly because a measurement system failed to report a value, then | ||||

any CompEp that uses sub-path N for that measurement interval is | ||||

undefined. | ||||

6.1.6. Statement of Conjecture | ||||

The empirical probability of loss calculated on a sufficiently large | The empirical probability of loss calculated on a sufficiently large | |||

stream of packets measured on each sub-path during the interval [T, | stream of packets measured on each sub-path during the interval [T, | |||

Tf] will be representative of the true loss probability (and the | Tf] will be representative of the true loss probability (and the | |||

probabilities themselves are sufficiently independent), such that the | probabilities themselves are sufficiently independent), such that the | |||

sub-path probabilities may be combined to produce an estimate of the | sub-path probabilities may be combined to produce an estimate of the | |||

complete path loss probability. | complete path loss probability. | |||

5.1.7. Justification of the Composition Function | 6.1.7. Justification of the Composition Function | |||

It is sometimes impractical to conduct active measurements between | ||||

every Src-Dst pair. For example, it may not be possible to collect | ||||

the desired sample size in each test interval when access link speed | ||||

is limited, because of the potential for measurement traffic to | ||||

degrade the user traffic performance. The conditions on a low-speed | ||||

access link may be understood well-enough to permit use of a small | ||||

sample size/rate, while a larger sample size/rate may be used on | ||||

other sub-paths. | ||||

Also, since measurement operations have a real monetary cost, there | ||||

is value in re-using measurements where they are applicable, rather | ||||

than launching new measurements for every possible source-destination | ||||

pair. | ||||

5.1.8. Sources of Deviation from the Ground Truth | See the common section. | |||

The measurement packets, each having source and destination addresses | 6.1.8. Sources of Deviation from the Ground Truth | |||

intended for collection at edges of the sub-path, may take a | ||||

different specific path through the network equipment and parallel | ||||

exchanges than packets with the source and destination addresses of | ||||

the complete path. Therefore, the sub-path measurements may differ | ||||

from the performance experienced by packets on the complete path. | ||||

Multiple measurements employing sufficient sub-path address pairs | ||||

might produce bounds on the extent of this error. | ||||

others... | See the common section. | |||

5.1.9. Specific cases where the conjecture might fail | 6.1.9. Specific cases where the conjecture might fail | |||

A concern for loss measurements combined in this way is that root | A concern for loss measurements combined in this way is that root | |||

causes may be correlated to some degree. | causes may be correlated to some degree. | |||

For example, if the links of different networks follow the same | For example, if the links of different networks follow the same | |||

physical route, then a single event like a tunnel fire could cause an | physical route, then a single event like a tunnel fire could cause an | |||

outage or congestion on remaining paths in multiple networks. Here | outage or congestion on remaining paths in multiple networks. Here | |||

it is important to ensure that measurements before the event and | it is important to ensure that measurements before the event and | |||

after the event are not combined to estimate the composite | after the event are not combined to estimate the composite | |||

performance. | performance. | |||

Or, when traffic volumes rise due to the rapid spread of an email- | Or, when traffic volumes rise due to the rapid spread of an email- | |||

born worm, loss due to queue overflow in one network may help another | born worm, loss due to queue overflow in one network may help another | |||

network to carry its traffic without loss. | network to carry its traffic without loss. | |||

others... | others... | |||

5.1.10. Application of Measurement Methodology | 6.1.10. Application of Measurement Methodology | |||

The methodology: | ||||

SHOULD use similar packets sent and collected separately in each sub- | ||||

path. | ||||

Allows a degree of flexibility (e.g., active or passive methods can | ||||

produce the "same" metric, but timing and correlation of passive | ||||

measurements is much more challenging). | ||||

Poisson and/or Periodic streams are RECOMMENDED. | ||||

Applicable to both Inter-domain and Intra-domain composition. | ||||

SHOULD have synchronized measurement time intervals in all sub-paths, | ||||

but largely overlapping intervals MAY suffice. | ||||

REQUIRES assumption of sub-path independence w.r.t. the metric being | See the common section. | |||

defined/composed. | ||||

6. Delay Variation Metrics and Statistics | 7. Delay Variation Metrics and Statistics | |||

6.1. Name: Type-P-One-way-ipdv-refmin-Poisson/Periodic-Stream | 7.1. Name: Type-P-One-way-ipdv-refmin-Poisson/Periodic-Stream | |||

This metric is a necessary element of Composed Delay Variation | This metric is a necessary element of Composed Delay Variation | |||

metrics, and its definition does not formally exist elsewhere in IPPM | metrics, and its definition does not formally exist elsewhere in IPPM | |||

literature. | literature. | |||

6.1.1. Metric Parameters: | 7.1.1. Metric Parameters: | |||

In addition to the parameters of section 4.1.1: | In addition to the parameters of section 4.1.1: | |||

o TstampSrc[i], the wire time of packet[i] as measured at MP(Src) | o TstampSrc[i], the wire time of packet[i] as measured at MP(Src) | |||

o TstampDst[i], the wire time of packet[i] as measured at MP(Dst), | o TstampDst[i], the wire time of packet[i] as measured at MP(Dst), | |||

assigned to packets that arrive within a "reasonable" time. | assigned to packets that arrive within a "reasonable" time. | |||

o B, a packet length in bits | o B, a packet length in bits | |||

skipping to change at page 14, line 5 | skipping to change at page 15, line 11 | |||

addition to the criteria for F(first packet). If multiple packets | addition to the criteria for F(first packet). If multiple packets | |||

have equal minimum Type-P-Finite-One-way-Delay values, then the | have equal minimum Type-P-Finite-One-way-Delay values, then the | |||

value for the earliest arriving packet SHOULD be used. | value for the earliest arriving packet SHOULD be used. | |||

o MinDelay, the Type-P-Finite-One-way-Delay value for F(second | o MinDelay, the Type-P-Finite-One-way-Delay value for F(second | |||

packet) given above. | packet) given above. | |||

o N, the number of packets received at the Destination meeting the | o N, the number of packets received at the Destination meeting the | |||

F(first packet) criteria. | F(first packet) criteria. | |||

6.1.2. Definition and Metric Units | 7.1.2. Definition and Metric Units | |||

Using the definition above in section 4.1.2, we obtain the value of | Using the definition above in section 4.1.2, we obtain the value of | |||

Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream[i], the singleton | Type-P-Finite-One-way-Delay-Poisson/Periodic-Stream[i], the singleton | |||

for each packet[i] in the stream (a.k.a. FiniteDelay[i]). | for each packet[i] in the stream (a.k.a. FiniteDelay[i]). | |||

For each packet[i] that meets the F(first packet) criteria given | For each packet[i] that meets the F(first packet) criteria given | |||

above: Type-P-One-way-ipdv-refmin-Poisson/Periodic-Stream[i] = | above: Type-P-One-way-ipdv-refmin-Poisson/Periodic-Stream[i] = | |||

IPDVRefMin[i] = FiniteDelay[i] - MinDelay | IPDVRefMin[i] = FiniteDelay[i] - MinDelay | |||

where IPDVRefMin[i] is in units of time (seconds, milliseconds). | where IPDVRefMin[i] is in units of time (seconds, milliseconds). | |||

6.1.3. Discussion and other details | 7.1.3. Discussion and other details | |||

This metric produces a sample of delay variation normalized to the | This metric produces a sample of delay variation normalized to the | |||

minimum delay of the sample. The resulting delay variation | minimum delay of the sample. The resulting delay variation | |||

distribution is independent of the sending sequence (although | distribution is independent of the sending sequence (although | |||

specific FiniteDelay values within the distribution may be | specific FiniteDelay values within the distribution may be | |||

correlated, depending on various stream parameters such as packet | correlated, depending on various stream parameters such as packet | |||

spacing). This metric is equivalent to the IP Packet Delay Variation | spacing). This metric is equivalent to the IP Packet Delay Variation | |||

parameter defined in [Y.1540]. | parameter defined in [Y.1540]. | |||

6.1.4. Statistics: Mean, Variance, Skewness, Quanitle | 7.1.4. Statistics: Mean, Variance, Skewness, Quanitle | |||

We define the mean IPDVRefMin as follows (where all packets i= 1 | We define the mean IPDVRefMin as follows (where all packets i= 1 | |||

through N have a value for IPDVRefMin): | through N have a value for IPDVRefMin): | |||

Type-P-One-way-ipdv-refmin-Mean = MeanIPDVRefMin = | Type-P-One-way-ipdv-refmin-Mean = MeanIPDVRefMin = | |||

N | N | |||

--- | --- | |||

1 \ | 1 \ | |||

- * > (IPDVRefMin [i]) | - * > (IPDVRefMin [i]) | |||

N / | N / | |||

skipping to change at page 15, line 32 | skipping to change at page 16, line 32 | |||

--- | --- | |||

i = 1 | i = 1 | |||

------------------------------------------- | ------------------------------------------- | |||

/ \ | / \ | |||

| ( 3/2 ) | | | ( 3/2 ) | | |||

\ (N - 1) * VarIPDVRefMin / | \ (N - 1) * VarIPDVRefMin / | |||

We define the Quantile of the IPDVRefMin sample as the value where | We define the Quantile of the IPDVRefMin sample as the value where | |||

the specified fraction of points is less than the given value. | the specified fraction of points is less than the given value. | |||

6.1.5. Composition Functions: | 7.1.5. Composition Functions: | |||

The Type-P-One-way-Composite-ipdv-refmin-<something> for the complete | This section gives two alternative composition functions. The | |||

objective is to estimate a quantile of the complete path delay | ||||

variation distribution. The composed quantile will be estimated | ||||

using information from the sub-path delay variation distributions. | ||||

7.1.5.1. Approximate Convolution | ||||

The Type-P-One-way-Delay-Poisson/Periodic-Stream samples from each | ||||

sub-path are summarized as a histogram with 1 ms bins representing | ||||

the one-way delay distribution. | ||||

From [TBP], the distribution of the sum of independent random | ||||

variables can be derived using the relation: | ||||

Type-P-One-way-Composite-ipdv-refmin-quantile-a = | ||||

/ / | ||||

P(X + Y + Z <= a) = | | P(X <= a-y-z) * P(Y = y) * P(Z = z) dy dz | ||||

/ / | ||||

z y | ||||

where X, Y, and Z are random variables representing the delay | ||||

variation distributions of the sub-paths of the complete path, and a | ||||

is the quantile of interest. Note dy and dz indicate partial | ||||

integration here.This relation can be used to compose a quantile of | ||||

interest for the complete path from the sub-path delay distributions. | ||||

The histograms with 1 ms bins are discrete approximations of the | ||||

delay distributions. | ||||

7.1.5.2. new section | ||||

Type-P-One-way-Composite-ipdv-refmin-<something> for the complete | ||||

Source to Destination path can be calculated by combining statistics | Source to Destination path can be calculated by combining statistics | |||

of all the constituent sub-paths in the following process: | of all the constituent sub-paths in the following process: | |||

< see [Y.1541] > | < see [Y.1541] section 8 > | |||

6.1.6. Statement of Conjecture | 7.1.6. Statement of Conjecture | |||

6.1.7. Justification of the Composition Function | The delay distribution of a sufficiently large stream of packets | |||

measured on each sub-path during the interval [T, Tf] will be | ||||

sufficiently stationary and the sub-path distributions themselves are | ||||

sufficiently independent, so that summary information describing the | ||||

sub-path distributions can be combined to estimate the delay | ||||

distribution of complete path. | ||||

6.1.8. Sources of Deviation from the Ground Truth | 7.1.7. Justification of the Composition Function | |||

6.1.9. Specific cases where the conjecture might fail | See the common section. | |||

6.1.10. Application of Measurement Methodology | 7.1.8. Sources of Deviation from the Ground Truth | |||

7. Other Metrics and Statistics: One-way Combined Metric | In addition to the common deviations, the a few additional sources | |||

exist here. For one, very tight distributions with range on the | ||||

order of a few milliseconds are not accurately represented by a | ||||

histogram with 1 ms bins. This size was chosen assuming an implicit | ||||

requirement on accuracy: errors of a few milliseconds are acceptable | ||||

when assessing a composed distribution quantile. | ||||

Also, summary statistics cannot describe the subtleties of an | ||||

empirical distribution exactly, especially when the distribution is | ||||

very different from a classical form. Any procedure that uses these | ||||

statistics alone may incur error. | ||||

7.1.9. Specific cases where the conjecture might fail | ||||

If the delay distributions of the sub-paths are somehow correlated, | ||||

then neither of these composition functions will be reliable | ||||

estimators of the complete path distribution. | ||||

In practice, sub-path delay distributions with extreme outliers have | ||||

increased the error of the composed metric estimate. | ||||

7.1.10. Application of Measurement Methodology | ||||

See the common section. | ||||

8. Security Considerations | 8. Security Considerations | |||

8.1. Denial of Service Attacks | 8.1. Denial of Service Attacks | |||

This metric requires a stream of packets sent from one host (source) | This metric requires a stream of packets sent from one host (source) | |||

to another host (destination) through intervening networks. This | to another host (destination) through intervening networks. This | |||

method could be abused for denial of service attacks directed at | method could be abused for denial of service attacks directed at | |||

destination and/or the intervening network(s). | destination and/or the intervening network(s). | |||

skipping to change at page 17, line 32 | skipping to change at page 19, line 42 | |||

measurement to investigate the performance of different part of the | measurement to investigate the performance of different part of the | |||

network. | network. | |||

Editor's Questions for clarification: What additional information | Editor's Questions for clarification: What additional information | |||

would be provided to the decomposition process, beyond the | would be provided to the decomposition process, beyond the | |||

measurement of the complete path? | measurement of the complete path? | |||

Is the decomposition described above intended to estimate a metric | Is the decomposition described above intended to estimate a metric | |||

for some/all disjoint sub-paths involved in the complete path? | for some/all disjoint sub-paths involved in the complete path? | |||

>>>>>>>>>>>>>>>>>>RESOLUTION: treat this topic in a seperate memo | >>>>>>>>>>>>>>>>>>RESOLUTION: treat this topic in a separate memo | |||

>>>>>>>>>>>>>>>>>>> | >>>>>>>>>>>>>>>>>>> | |||

>>>>>>>>>>>>>>>>>>>Issue | >>>>>>>>>>>>>>>>>>>Issue | |||

Section 7 defines a new type of metric, a "combination" of metrics | Section 7 defines a new type of metric, a "combination" of metrics | |||

for one-way delay and packet loss. The purpose of this metric is to | for one-way delay and packet loss. The purpose of this metric is to | |||

link these two primary metrics in a convenient way. | link these two primary metrics in a convenient way. | |||

Readers are asked to comment on the efficiency of the combination | Readers are asked to comment on the efficiency of the combination | |||

skipping to change at page 18, line 23 | skipping to change at page 20, line 33 | |||

>>>>>>>>>>>>>>>>RESOLUTION: No and Yes. | >>>>>>>>>>>>>>>>RESOLUTION: No and Yes. | |||

11. Acknowledgements | 11. Acknowledgements | |||

12. References | 12. References | |||

12.1. Normative References | 12.1. Normative References | |||

[I-D.ietf-ippm-framework-compagg] | [I-D.ietf-ippm-framework-compagg] | |||

Morton, A. and S. Berghe, "Framework for Metric | Morton, A. and S. Berghe, "Framework for Metric | |||

Composition", draft-ietf-ippm-framework-compagg-01 (work | Composition", draft-ietf-ippm-framework-compagg-03 (work | |||

in progress), June 2006. | in progress), March 2007. | |||

[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. | |||

[RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way | [RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way | |||

Delay Metric for IPPM", RFC 2679, September 1999. | Delay Metric for IPPM", RFC 2679, September 1999. | |||

skipping to change at page 19, line 31 | skipping to change at page 22, line 4 | |||

Al Morton | Al Morton | |||

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 | Emile Stephan | |||

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@francetelecom.com | Email: emile.stephan@orange-ftgroup.com | |||

URI: | URI: | |||

Full Copyright Statement | Full Copyright Statement | |||

Copyright (C) The Internet Society (2006). | Copyright (C) The IETF Trust (2007). | |||

This document is subject to the rights, licenses and restrictions | This document is subject to the rights, licenses and restrictions | |||

contained in BCP 78, and except as set forth therein, the authors | contained in BCP 78, and except as set forth therein, the authors | |||

retain all their rights. | retain all their rights. | |||

This document and the information contained herein are provided on an | This document and the information contained herein are provided on an | |||

"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS | "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS | |||

OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET | OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND | |||

ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, | THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS | |||

INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE | OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF | |||

INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED | THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED | |||

WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. | WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. | |||

Intellectual Property | Intellectual Property | |||

The IETF takes no position regarding the validity or scope of any | The IETF takes no position regarding the validity or scope of any | |||

Intellectual Property Rights or other rights that might be claimed to | Intellectual Property Rights or other rights that might be claimed to | |||

pertain to the implementation or use of the technology described in | pertain to the implementation or use of the technology described in | |||

this document or the extent to which any license under such rights | this document or the extent to which any license under such rights | |||

might or might not be available; nor does it represent that it has | might or might not be available; nor does it represent that it has | |||

made any independent effort to identify any such rights. Information | made any independent effort to identify any such rights. Information | |||

End of changes. 74 change blocks. | ||||

203 lines changed or deleted | | 315 lines changed or added | ||

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