draft-ietf-ippm-framework-compagg-06.txt   draft-ietf-ippm-framework-compagg-07.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: August 8, 2008 Ghent University - IBBT Expires: May 2, 2009 Ghent University - IBBT
February 5, 2008 October 29, 2008
Framework for Metric Composition Framework for Metric Composition
draft-ietf-ippm-framework-compagg-06 draft-ietf-ippm-framework-compagg-07
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Copyright (C) The IETF Trust (2008).
Abstract Abstract
This memo describes a framework for composing and aggregating metrics This memo describes a detailed framework for composing and
(both in time and in space) defined by RFC 2330 and developed by the aggregating metrics (both in time and in space) originally defined by
IPPM working group. The framework describes the generic composition the IP Performance Metrics (IPPM) RFC 2330 and developed by the IETF.
and aggregation mechanisms. It provides a basis for additional This new framework memo describes the generic composition and
documents that implement this framework for detailed, and practically aggregation mechanisms. The memo provides a basis for additional
useful, compositions and aggregations of metrics. documents that implement the framework to define detailed
compositions and aggregations of metrics which are useful in
practice.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
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2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 6 2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 6
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Measurement Point . . . . . . . . . . . . . . . . . . . . 6 3.1. Measurement Point . . . . . . . . . . . . . . . . . . . . 6
3.2. Complete Path . . . . . . . . . . . . . . . . . . . . . . 7 3.2. Complete Path . . . . . . . . . . . . . . . . . . . . . . 7
3.3. Complete Path Metric . . . . . . . . . . . . . . . . . . . 7 3.3. Complete Path Metric . . . . . . . . . . . . . . . . . . . 7
3.4. Complete Time Interval . . . . . . . . . . . . . . . . . . 7 3.4. Complete Time Interval . . . . . . . . . . . . . . . . . . 7
3.5. Composed Metric . . . . . . . . . . . . . . . . . . . . . 7 3.5. Composed Metric . . . . . . . . . . . . . . . . . . . . . 7
3.6. Composition Function . . . . . . . . . . . . . . . . . . . 7 3.6. Composition Function . . . . . . . . . . . . . . . . . . . 7
3.7. Index . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.7. Index . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.8. Ground Truth . . . . . . . . . . . . . . . . . . . . . . . 8 3.8. Ground Truth . . . . . . . . . . . . . . . . . . . . . . . 8
3.9. Sub-interval . . . . . . . . . . . . . . . . . . . . . . . 8 3.9. Interval . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.10. Sub-path . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.10. Sub-interval . . . . . . . . . . . . . . . . . . . . . . . 8
3.11. Sub-path Metrics . . . . . . . . . . . . . . . . . . . . . 8 3.11. Sub-path . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.12. Sub-path Metrics . . . . . . . . . . . . . . . . . . . . . 8
4. Description of Metric Types . . . . . . . . . . . . . . . . . 8 4. Description of Metric Types . . . . . . . . . . . . . . . . . 8
4.1. Temporal Aggregation Description . . . . . . . . . . . . . 8 4.1. Temporal Aggregation Description . . . . . . . . . . . . . 8
4.2. Spatial Aggregation Description . . . . . . . . . . . . . 9 4.2. Spatial Aggregation Description . . . . . . . . . . . . . 9
4.3. Spatial Composition Description . . . . . . . . . . . . . 10 4.3. Spatial Composition Description . . . . . . . . . . . . . 10
4.4. Help Metrics . . . . . . . . . . . . . . . . . . . . . . . 10 4.4. Help Metrics . . . . . . . . . . . . . . . . . . . . . . . 10
4.5. Higher Order Composition . . . . . . . . . . . . . . . . . 10 4.5. Higher Order Composition . . . . . . . . . . . . . . . . . 10
5. Requirements for Composed Metrics . . . . . . . . . . . . . . 11 5. Requirements for Composed Metrics . . . . . . . . . . . . . . 11
6. Guidelines for Defining Composed Metrics . . . . . . . . . . . 12 6. Guidelines for Defining Composed Metrics . . . . . . . . . . . 12
6.1. Ground Truth: Comparison with other IPPM Metrics . . . . . 12 6.1. Ground Truth: Comparison with other IPPM Metrics . . . . . 12
6.1.1. Ground Truth for Temporal Aggregation . . . . . . . . 14 6.1.1. Ground Truth for Temporal Aggregation . . . . . . . . 14
6.1.2. Ground Truth for Spatial Aggregation . . . . . . . . . 14 6.1.2. Ground Truth for Spatial Aggregation . . . . . . . . . 14
6.2. Deviation from the Ground Truth . . . . . . . . . . . . . 14 6.2. Deviation from the Ground Truth . . . . . . . . . . . . . 14
6.3. Incomplete Information . . . . . . . . . . . . . . . . . . 14 6.3. Incomplete Information . . . . . . . . . . . . . . . . . . 15
6.4. Time Varying Metrics . . . . . . . . . . . . . . . . . . . 15 6.4. Time Varying Metrics . . . . . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
8. Security Considerations . . . . . . . . . . . . . . . . . . . 15 8. Security Considerations . . . . . . . . . . . . . . . . . . . 15
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
10.1. Normative References . . . . . . . . . . . . . . . . . . . 15 10.1. Normative References . . . . . . . . . . . . . . . . . . . 16
10.2. Informative References . . . . . . . . . . . . . . . . . . 16 10.2. Informative References . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
Intellectual Property and Copyright Statements . . . . . . . . . . 17 Intellectual Property and Copyright Statements . . . . . . . . . . 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. Also, the text 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.
This memo expands on the notion of composition, and provides a This memo expands on the notion of composition, and provides a
detailed framework for several classes of metrics that were mentioned detailed framework for several classes of metrics that were described
in the original IPPM framework. The classes include temporal in the original IPPM framework. The classes include temporal
aggregation, spatial aggregation, and spatial composition. aggregation, spatial aggregation, and spatial composition.
1.1. Motivation 1.1. Motivation
Network operators have deployed measurement systems to serve many Network operators have deployed measurement systems to serve many
purposes, including performance monitoring, maintenance support, purposes, including performance monitoring, maintenance support,
network engineering, and reporting performance to customers. The network engineering, and reporting performance to customers. The
collection of elementary measurements alone is not enough to collection of elementary measurements alone is not enough to
understand a network's behaviour. In general, measurements need to understand a network's behaviour. In general, measurements need to
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The answer lies in temporal aggregation, where the short-term The answer lies in temporal aggregation, where the short-term
measurements needed by the operations community are combined to measurements needed by the operations community are combined to
estimate a longer-term result for others. Also, problems with the estimate a longer-term result for others. Also, problems with the
measurement system itself may be isolated to one or more of the measurement system itself may be isolated to one or more of the
short-term measurements, rather than possibly invalidating an entire short-term measurements, rather than possibly invalidating an entire
long-term measurement if the problem was undetected. long-term measurement if the problem was undetected.
1.1.3. Data Reduction and Consolidation 1.1.3. Data Reduction and Consolidation
Another motivation is data reduction. Assume there is a network Another motivation is data reduction. Assume there is a network in
domain in which delay measurements are performed among a subset of which delay measurements are performed among a subset of its nodes.
its nodes. A network manager might ask whether there is a problem A network manager might ask whether there is a problem with the
with the network delay in general. It would be desirable to obtain a network delay in general. It would be desirable to obtain a single
single value that gives an indication of the overall network delay. value that gives an indication of the overall network delay. Spatial
Spatial aggregation methods would address this need, and can produce aggregation methods would address this need, and can produce the
the desired "single figure of merit" asked for, one that may also be desired "single figure of merit" asked for, one that may also be
useful in trend analysis. useful in trend analysis.
The overall value would be calculated from the elementary delay The overall value would be calculated from the elementary delay
measurements, but it not obvious how: for example, it may not to be measurements, but it not obvious how: for example, it may not to be
reasonable to average all delay measurements, as some paths (e.g. reasonable to average all delay measurements, as some paths (e.g.
having a higher bandwidth or more important customers) might be having a higher bandwidth or more important customers) might be
considered more critical than others. considered more critical than others.
Metric composition can help to provide, from raw measurement data, Metric composition can help to provide, from raw measurement data,
some tangible, well-understood and agreed upon information about the some tangible, well-understood and agreed upon information about the
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The term Measurement Point is synonymous with the term "observation The term Measurement Point is synonymous with the term "observation
position" used in [RFC2330] when describing the notion of wire time. position" used in [RFC2330] when describing the notion of wire time.
A measurement point may be at the boundary between a host and an A measurement point may be at the boundary between a host and an
adjacent link (physical), or it may be within a host (logical) that adjacent link (physical), or it may be within a host (logical) that
performs measurements where the difference between host time and wire performs measurements where the difference between host time and wire
time is understood. time is understood.
3.2. Complete Path 3.2. Complete Path
The complete path is the actual path that a packet would follow as it The complete path is the actual path that a packet would follow as it
travels from the packet's Source to its Destination. travels from the packet's Source to its Destination. A Complete path
may span the administrative boundaries of one or more networks.
3.3. Complete Path Metric 3.3. Complete Path Metric
The complete path metric is the Source to Destination metric that a The complete path metric is the Source to Destination metric that a
composed metric attempts to estimate. A complete path metric composed metric attempts to estimate. A complete path metric
represents the ground-truth for a composed metric. represents the ground-truth for a composed metric.
3.4. Complete Time Interval 3.4. Complete Time Interval
The complete time interval is comprised of two or more contiguous The complete time interval is comprised of two or more contiguous
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PMOL Framework? PMOL Framework?
3.8. Ground Truth 3.8. Ground Truth
As applied here, the notion of ground truth is defined as the actual As applied here, the notion of ground truth is defined as the actual
performance of a network path over some time interval. The ground performance of a network path over some time interval. The ground
truth is a metric on the (unavailable) packet transfer information truth is a metric on the (unavailable) packet transfer information
for the desired path and time interval that a composed metric seeks for the desired path and time interval that a composed metric seeks
to estimate. to estimate.
3.9. Sub-interval 3.9. Interval
A span of time.
3.10. Sub-interval
A Sub-interval is a time interval that is included in another A Sub-interval is a time interval that is included in another
interval. interval.
3.10. Sub-path 3.11. 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 this sub-path is "involved" in the complete path. path. We say that this sub-path is "involved" in the complete path.
3.11. Sub-path Metrics 3.12. 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
Composite metric, quantifying some aspect of the performance a Composite metric, quantifying some aspect of the performance a
particular sub-path from its Source to Destination. particular sub-path from its Source to Destination.
4. Description of Metric Types 4. Description of Metric Types
This section defines the various classes of Composition. There are This section defines the various classes of Composition. There are
two classes more accurately described as aggregation over time and two classes more accurately described as aggregation over time and
space, and the third involves concatenation in space. space, and the third involves concatenation in space.
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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 >>>>>>>>Comment: Why no forecasting? This was apparently a limit on
the Geant2 project, but may not apply here. 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 domain. 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 domain (where the inputs are already metric of a network (where the inputs are already metric "statistics").
"statistics"). Since we wish to include the effect of the traffic Since we wish to include the effect of the traffic matrix on the
matrix on the result, it makes sense to weight each metric according result, it makes sense to weight each metric according to the traffic
to the traffic carried on the corresponding OD pair: carried on the corresponding OD pair:
OWD_sum=f1*OWD_1+f2*OWD_2+...+fn*OWD_n OWD_sum=f1*OWD_1+f2*OWD_2+...+fn*OWD_n
where fi=load_OD_i/total_load. where fi=load_OD_i/total_load.
A simple average OWD across all network OD pairs would not use the A simple average OWD across all network OD pairs would not use the
traffic weighting. traffic weighting.
Another example metric that is "aggregated in space", is the maximum Another example metric that is "aggregated in space", is the maximum
edge-to-edge delay across a single domain. Assume that a Service edge-to-edge delay across a single network. Assume that a Service
Provider wants to advertise the maximum delay that transit traffic Provider wants to advertise the maximum delay that transit traffic
will experience while passing through his/her domain. There can be will experience while passing through his/her network. There can be
multiple edge-to-edge paths across a domain, and the Service Provider multiple edge-to-edge paths across a network, and the Service
chooses either to publish a list of delays (each corresponding to a Provider chooses either to publish a list of delays (each
specific edge-to-edge path), or publish a single maximum value. The corresponding to a specific edge-to-edge path), or publish a single
latter approach simplifies the publication of measurement maximum value. The latter approach simplifies the publication of
information, and may be sufficient for some purposes. Similar measurement information, and may be sufficient for some purposes.
operations can be provided to other metrics, e.g. "maximum edge-to- Similar operations can be provided to other metrics, e.g. "maximum
edge packet loss", etc. edge-to-edge packet loss", etc.
We suggest that space aggregation is generally useful to obtain a We suggest that space aggregation is generally useful to obtain a
summary view of the behaviour of large network portions, or in summary view of the behaviour of large network portions, or in
general of coarser aggregates. The metric collection time instant, general of coarser aggregates. The metric collection time instant,
i.e. the metric collection time window of measured metrics is not i.e. the metric collection time window of measured metrics is not
considered in space aggregation. We assume that either it is considered in space aggregation. We assume that either it is
consistent for all the composed metrics, e.g. compose a set of consistent for all the composed metrics, e.g. compose a set of
average delays all referred to the same time window, or the time average delays all referred to the same time window, or the time
window of each composed metric does not affect aggregated metric. window of each composed metric does not affect aggregated metric.
4.3. Spatial Composition Description 4.3. Spatial Composition Description
Concatenation in space is defined as the composition of metrics of Concatenation in space is defined as the composition of metrics of
same type and (ideally) different spatial scope, so that the same type and (ideally) different spatial scope, so that the
resulting metric is representative of what the metric would be if resulting metric is representative of what the metric would be if
obtained with a direct measurement over the sequence of the several obtained with a direct measurement over the sequence of the several
spatial scopes. An example is the sum of OWDs of different edge-to- spatial scopes. An example is the sum of OWDs of different edge-to-
edge domain's delays, where the intermediate edge points are close to edge network's delays, where the intermediate edge points are close
each other or happen to be the same. In this way, we can for example to each other or happen to be the same. In this way, we can for
estimate OWD_AC starting from the knowledge of OWD_AB and OWD_BC. example estimate OWD_AC starting from the knowledge of OWD_AB and
Note that there may be small gaps in measurement coverage, likewise OWD_BC. Note that there may be small gaps in measurement coverage,
there may be small overlaps (e.g., the link where test equipment likewise there may be small overlaps (e.g., the link where test
connects to the network). equipment connects to the network).
One key difference from examples of aggregation in space is that all One key difference from examples of aggregation in space is that all
sub-paths contribute equally to the composed metric, independent of sub-paths contribute equally to the composed metric, independent of
the traffic load present. the traffic load present.
4.4. Help Metrics 4.4. Help Metrics
In practice there is often the need to compute a new metric using one In practice there is often the need to compute a new metric using one
or more metrics with the same spatial and time scope. For example, or more metrics with the same spatial and time scope. For example,
the metric rtt_sample_variance may be computed from two different the metric rtt_sample_variance may be computed from two different
metrics: the help metrics rtt_square_sum and the rtt_sum. The metrics: the help metrics rtt_square_sum and the rtt_sum. The
process of using help metrics is a simple calculation and not an process of using help metrics is a simple calculation and not an
aggregation or a concatenation, and will not be investigated further aggregation or a concatenation, and will not be investigated further
in this memo. in this memo.
4.5. Higher Order Composition 4.5. Higher Order Composition
Composed metrics might themselves be subject to further steps of Composed metrics might themselves be subject to further steps of
composition or aggregation. An example would be the delay of a composition or aggregation. An example would be the delay of a
maximal domain obtained through the spatial composition of several maximal path obtained through the spatial composition of several
composed delays for each domain in the maximal domain (obtained composed delays for each Complete Path in the maximal path (obtained
through spatial composition). All requirements for first order through spatial composition). All requirements for first order
composition metrics apply to higher order composition. composition metrics apply to higher order composition.
An example using temporal aggregation: twelve 5-minute metrics are An example using temporal aggregation: twelve 5-minute metrics are
aggregated to estimate the performance over an hour. The seconds aggregated to estimate the performance over an hour. The seconds
step of aggregation would take 24 hourly metrics and estimate the step of aggregation would take 24 hourly metrics and estimate the
performance over a day. performance over a day.
5. Requirements for Composed Metrics 5. Requirements for Composed Metrics
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For each metric, the applicable circumstances will be defined, in For each metric, the applicable circumstances will be defined, in
terms of whether the composition or aggregation: terms of whether the composition or aggregation:
o Requires homogeneity of measurement methodologies, or can allow a o Requires homogeneity of measurement methodologies, or can allow a
degree of flexibility (e.g., active or passive methods produce the degree of flexibility (e.g., active or passive methods produce the
"same" metric). Also, the applicable sending streams will be "same" metric). Also, the applicable sending streams will be
specified, such as Poisson, Periodic, or both. specified, such as Poisson, Periodic, or both.
o Needs information or access that will only be available within an o Needs information or access that will only be available within an
operator's domain, or is applicable to Inter-domain composition. operator's network, or is applicable to Inter-network composition.
o Requires precisely synchronized measurement time intervals in all o Requires precisely synchronized measurement time intervals in all
component metrics, or loosely synchronized, or no timing component metrics, or loosely synchronized, or no timing
requirements. requirements.
o Requires assumption of component metric independence w.r.t. the o Requires assumption of component metric independence w.r.t. the
metric being defined/composed, or other assumptions. metric being defined/composed, or other assumptions.
o Has known sources of inaccuracy/error, and identifies the sources. o Has known sources of inaccuracy/error, and identifies the sources.
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++ ++ ++ ++ ++ ++ ++ ++
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 I-D.ietf-ippm-multimetrics Further, we observe that a Spatial Metric
[I-D.ietf-ippm-multimetrics]collected for packets traveling over the [I-D.ietf-ippm-multimetrics]collected for packets traveling over the
same set of sub-paths provide a basis for the Ground Truth of the same set of sub-paths provide a basis for the Ground Truth of the
individual Sub-Path metrics. We note that mathematical operations individual Sub-Path metrics. We note that mathematical operations
may be necessary to isolate the performance of each sub-path. may be necessary to isolate the performance of each sub-path.
Next, we consider multiparty metrics as defined in [I-D.ietf-ippm- Next, we consider multiparty metrics as defined in [I-D.ietf-ippm-
multimetrics], and their spatial composition. Measurements to each multimetrics], and their spatial composition. Measurements to each
of the Receivers produce an element of the one-to-group metric. of the Receivers produce an element of the one-to-group metric.
These elements can be composed from sub-path metrics and the composed These elements can be composed from sub-path metrics and the composed
metrics can be combined to create a composed one-to-group metric. metrics can be combined to create a composed one-to-group metric.
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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] [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-05 (work in progress), draft-ietf-ippm-multimetrics-09 (work in progress),
November 2007. October 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,
"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.
skipping to change at page 17, line 44 skipping to change at line 752
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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