Internet DRAFT - draft-manyfolks-ippm-metric-registry
draft-manyfolks-ippm-metric-registry
Network Working Group M. Bagnulo
Internet-Draft UC3M
Intended status: Best Current Practice B. Claise
Expires: August 16, 2014 Cisco Systems, Inc.
P. Eardley
BT
A. Morton
AT&T Labs
February 12, 2014
Registry for Performance Metrics
draft-manyfolks-ippm-metric-registry-00
Abstract
This document specifies the common aspects of the IANA registry for
performance metrics, both active and passive categories. This
document also gives a set of guidelines for Registered Performance
Metric requesters and reviewers.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 16, 2014.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Open Issues and Resolutions . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. Design Considerations for the Registry and Registered Metrics 7
5.1. Interoperability . . . . . . . . . . . . . . . . . . . . 7
5.2. Criteria for Registered Performance Metrics . . . . . . . 8
5.3. Single point of reference for Performance metrics . . . . 8
5.4. Side benefits . . . . . . . . . . . . . . . . . . . . . . 9
6. Performance Metric Registry: Prior attempt . . . . . . . . . 9
6.1. Why this Attempt Will Succeed? . . . . . . . . . . . . . 10
7. Common Columns of the Performance Metric Registry . . . . . . 10
7.1. Performance Metrics Identifier . . . . . . . . . . . . . 11
7.2. Performance Metrics Name . . . . . . . . . . . . . . . . 11
7.3. Performance Metrics Status . . . . . . . . . . . . . . . 12
7.4. Performance Metrics Requester . . . . . . . . . . . . . . 12
7.5. Performance Metrics Revision . . . . . . . . . . . . . . 12
7.6. Performance Metrics Revision Date . . . . . . . . . . . . 13
7.7. Performance Metrics Description . . . . . . . . . . . . . 13
7.8. Reference Specification(s) . . . . . . . . . . . . . . . 13
8. The Life-Cycle of Registered Metrics . . . . . . . . . . . . 13
8.1. The Process for Review by the Performance Metric Experts 13
8.2. Revising Registered Performance Metrics . . . . . . . . . 14
8.3. Deprecating Registered Performance Metrics . . . . . . . 16
9. Performance Metric Registry and other Registries . . . . . . 16
10. Security considerations . . . . . . . . . . . . . . . . . . . 17
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
13.1. Normative References . . . . . . . . . . . . . . . . . . 17
13.2. Informative References . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Open Issues and Resolutions
1. I believe that the Performance Metrics Experts and the
Performance Metric Directorate will be a different group of
people. Reason: every single time a new expert is added, the
IESG needs to approve her/him. To be discussed with the Area
Directors. *** (v7) Has this discussion taken place? If these
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are different groups, we don't need to define Performance
Metrics Directorate.
2. We should expand on the different roles and responsibilities of
the Performance Metrics Experts versus the Performance Metric
Directorate. At least, the Performance Metric Directorate one
should be expanded. --- (v7) If these are different entities,
our only concern is the role of the "PM Experts".
3. Not sure if this is interesting for this document to go in the
details of the LMAP control protocol versus report protocol (see
section 'Interoperability'. (the text currently does this in
several sections, S5 comes to mind - Closed)
4. Marcelo, not sure what you mean by 'Single point of reference'.
(Closed - see S5.3)
5. Define 'Measurement Parameter'. Even if this is active
monitoring specific term, we need it in this draft. Done in v3
Terminology section as "Input Parameter". - Closed in v7 as
"Parameter".
6. Performance Metric Description: part of this document of the
active/ passive monitoring documents. -- Closed will be Part of
Active & Passive docs.
7. Many aspects of the Naming convention are TBD, and need
discussion. For example, we have distinguished RTCP-XR metrics
as End-Point (neither active nor passive in the traditional
sense, so not Act_ or Pas_). Also, the Act_ or Pas_ component
is not consistent with "camel_case", as Marcelo points out.
Even though we may not cast all naming conventions in stone at
the start, it will be helpful to look at several examples of
passive metric names now.
8. RTCP-XR metrics are currently referred to as "end-point", and
have aspects that similar to active (the measured stream
characteristics are known a priori and measurement commonly
takes place at the end-points of the path) and passive (there is
no additional traffic dedicated to measurement, with the
exception of the RTCP report packets themselves). We have one
example expressing an end-point metric in the active sub-
registry memo.
9. Revised Registry Entries: Keep for history (deprecated) or
Delete?
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10. In section 7 defining the Registry Common Columns, ~all column
names begin with "Performance Metric". Al recommends deleting
this prefix in each sub-section as redundant.
2. Introduction
The IETF specifies and uses Performance Metrics of protocols and
applications transported over its protocols. Performance metrics are
such an important part of the operations of IETF protocols that
[RFC6390] specifies guidelines for their development.
The definition and use of Performance Metrics in the IETF happens in
various working groups (WG), most notably:
The "IP Performance Metrics" (IPPM) WG is the WG primarily
focusing on Performance Metrics definition at the IETF.
The "Metric Blocks for use with RTCP's Extended Report Framework"
(XRBLOCK) WG recently specified many Performance Metrics related
to "RTP Control Protocol Extended Reports (RTCP XR)" [RFC3611],
which establishes a framework to allow new information to be
conveyed in RTCP, supplementing the original report blocks defined
in "RTP: A Transport Protocol for Real-Time Applications",
[RFC3550].
The "Benchmarking Methodology" WG (BMWG) defined many Performance
Metrics for use in laboratory benchmarking of inter-networking
technologies.
The "IP Flow Information eXport" (IPFIX) WG Information elements
related to Performance Metrics are currently proposed.
The "Performance Metrics for Other Layers" (PMOL) concluded WG,
defined some Performance Metrics related to Session Initiation
Protocol (SIP) voice quality [RFC6035].
It is expected that more Performance Metrics will be defined in the
future, not only IP-based metrics, but also metrics which are
protocol-specific and application-specific.
However, despite the importance of Performance Metrics, there are two
related problems for the industry. First, how to ensure that when
one party requests another party to measure (or report or in some way
act on) a particular performance metric, then both parties have
exactly the same understanding of what performance metric is being
referred to. Second, how to discover which Performance Metrics have
been specified, so as to avoid developing new performance metric that
is very similar. The problems can be addressed by creating a
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registry of performance metrics. The usual way in which IETF
organizes namespaces is with Internet Assigned Numbers Authority
(IANA) registries, and there is currently no Performance Metrics
Registry maintained by the IANA.
This document therefore proposes the creation of a Performance
Metrics Registry. It also provides best practices on how to define
new or updated entries in the Performance Metrics Registry.
3. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC2119].
The terms Performance Metric and Performance Metrics Directorate are
defined in [RFC6390], and copied over in this document for the
readers convenience.
Registered Performance Metric: A Registered Performance Metric (or
Registered Metric) is a quantitative measure of performance (see
section 6.1 of [RFC2330]) expressed as an entry in the Performance
Metric Registry, and comprised of a specifically named metric
which has met all the registry review criteria, is under the
curation of IETF Performance Metrics Experts, and whose changes
are controlled by IANA.
Registry or Performance Metrics Registry: The IANA registry
containing Registered Performance Metrics.
Non-IANA Registry: A set of metrics that are registered locally (and
not by IANA).
Performance Metrics Experts: The Performance Metrics Experts is a
group of experts selected by the IESG to validate the Performance
Metrics before updating the Performance Metrics Registry. The
Performance Metrics Experts work closely with IANA.
Performance Metrics Directorate: The Performance Metrics Directorate
is a directorate that provides guidance for Performance Metrics
development in the IETF. The Performance Metrics Directorate
should be composed of experts in the performance community,
potentially selected from the IP Performance Metrics (IPPM),
Benchmarking Methodology (BMWG), and Performance Metrics for Other
Layers (PMOL) WGs.
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Parameter: An input factor defined as a variable in the definition
of a metric. A numerical or other specified factor forming one of
a set that defines a metric or sets the conditions of its
operation. Most Input Parameters do not change the fundamental
nature of the metric's definition, but others have substantial
influence. All Input Parameters must be known to measure using a
metric and interpret the results.
Active Measurement Method: Methods of Measurement conducted on
traffic which serves only the purpose of measurement and is
generated for that reason alone, and whose traffic characteristics
are known a priori. An Internet user's host can generate active
measurement traffic (virtually all typical user-generated traffic
is not dedicated to active measurement, but it can produce such
traffic with the necessary application operating).
Passive Measurement Method: Methods of Measurement conducted on
Internet user traffic such that sensitive information is present
and may be stored in the measurement system, or observations of
traffic from other sources for monitoring and measurement
purposes.
Hybrid Measurement Method: Methods of Measurement which use a
combination of Active Measurement and Passive Measurement methods.
4. Scope
The intended audience of this document includes those who prepare and
submit a request for a Registered Performance Metric, and for the
Performance Metric Experts who review a request.
This document specifies a Performance Metrics Registry in IANA. This
Performance Metric Registry is applicable to Performance Metrics
issued from Active Measurement, Passive Measurement, or from end-
point calculation. This registry is designed to encompass
performance metrics developed throughout the IETF and especially for
the following working groups: IPPM, XRBLOCK, IPFIX, BMWG, and
possibly others. This document analyzes an prior attempt to set up a
Performance Metric Registry, and the reasons why this design was
inadequate [RFC6248]. Finally, this document gives a set of
guidelines for requesters and expert reviewers of candidate
Registered Performance Metrics.
This document serves as the foundation for further work. It
specifies the set of columns describing common aspects necessary for
all entries in the Performance Metrics Registry.
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Two documents describing sub-registries will be developed separately:
one for active Registered Metrics and another one for the passive
Registered Metrics. Indeed, active and passive performance metrics
appear to have different characteristics which must be documented in
their respective sub-registies. For example, active performance
methods must specify the packet stream characteristics they generate
and measure, so it is essential to include the stream specifications
in the registry entry. In the case of passive Performance metrics,
there is a need to specify the sampling distribution in the registry,
while it would be possible to force the definition of the registry
field to include both types of distributions in the same registry
column, we believe it is cleaner and clearer to have separated sub-
registries with different columns that have a narrow definition.
It is possible that future metrics may be a hybrid of active and
passive measurement methods, and it may be possible to register
hybrid metrics using in one of the two planned sub-registries (active
or passive), or it may be efficient to define a third sub-registry
with unique columns. The current design with sub-registries allows
for growth, and this is a recognized option for extension.
This document makes no attempt to populate the registry with initial
entries.
Based on [RFC5226] Section 4.3, this document is processed as Best
Current Practice (BCP) [RFC2026].
5. Design Considerations for the Registry and Registered Metrics
In this section, we detail several design considerations that are
relevant for understanding the motivations and expected use of the
metric registry.
5.1. Interoperability
As any IETF registry, the primary use for a registry is to manage a
namespace for its use within one or more protocols. In this
particular case of the metric registry, there are two types of
protocols that will use the values defined in the registry for their
operation:
o Control protocol: this type of protocols is used to allow one
entity to request another entity to perform a measurement using a
specific metric defined by the registry. One particular example
is the LMAP framework [I-D.ietf-lmap-framework]. Using the LMAP
terminology, the registry is used in the LMAP Control protocol to
allow a Controller to request a measurement task to one or more
Measurement Agents. In order to enable this use case, the entries
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of the metric registry must be well enough defined to allow a
Measurement Agent implementation to trigger a specific measurement
task upon the reception of a control protocol message. This
requirements heavily constrains the type of entries that are
acceptable for the Metric registry.
o Report protocol: This type of protocols is used to allow an entity
to report measurement results to another entity. By referencing
to a specific metric registry, it is possible to properly
characterize the measurement result data being transferred. Using
the LMAP terminology, the registry is used in the Report protocol
to allow a Measurement Agent to report measurement results to a
Collector.
5.2. Criteria for Registered Performance Metrics
It is neither possible nor desirable to populate the registry with
all combinations of input parameters of all performance metrics. The
Registered Performance Metrics should be:
1. interpretable by the user.
2. implementable by the software designer.
3. deployable by network operators, without major impact on the
networks.
4. accurate, for interoperability and deployment across vendors
In essence, there needs to be evidence that a candidate registry
entry has significant industry interest, or has seen deployment, and
there is agreement that the candidate Registered Metric serves its
intended purpose.
5.3. Single point of reference for Performance metrics
A registry for Performance metrics serves as a single point of
reference for performance metrics defined in different working groups
in the IETF. As we mentioned earlier, there are several WGs that
define performance metrics in the IETF and it is hard to keep track
of all them. This results in multiple definitions of similar metrics
that attempt to measure the same phenomena but in slightly different
(and incompatible) ways. Having a registry would allow both the IETF
community and external people to have a single list of relevant
performance metrics defined by the IETF (and others, where
appropriate). The single list is also an essential aspect of
communication about metrics, where different entities that request
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measurements, execute measurements, and report the results can
benefit from a common understanding of the referenced metric.
5.4. Side benefits
There are a couple of side benefits of having such a registry.
First, the registry could serve as an inventory of useful and used
metrics, that are normally supported by different implementations of
measurement agents. Second, the results of the metrics would be
comparable even if they are performed by different implementations
and in different networks, as the metric is properly defined. BCP
176 [RFC6576] examines whether the results produced by independent
implementations are equivalent in the context of evaluating the
completeness and clarity of metric specifications. This BCP defines
the standards track advancement testing for (active) IPPM metrics,
and the same process will likely suffice to determine whether
registry entries are sufficiently well specified to result in
comparable (or equivalent) results. Registry entries which have
undergone such testing SHOULD be noted, with a reference to the test
results.
6. Performance Metric Registry: Prior attempt
There was a previous attempt to define a metric registry RFC 4148
[RFC4148]. However, it was obsoleted by RFC 6248 [RFC6248] because
it was "found to be insufficiently detailed to uniquely identify IPPM
metrics... [there was too much] variability possible when
characterizing a metric exactly" which led to the RFC4148 registry
having "very few users, if any".
A couple of interesting additional quotes from RFC 6248 might help
understand the issues related to that registry.
1. "It is not believed to be feasible or even useful to register
every possible combination of Type P, metric parameters, and
Stream parameters using the current structure of the IPPM Metrics
Registry."
2. "The registry structure has been found to be insufficiently
detailed to uniquely identify IPPM metrics."
3. "Despite apparent efforts to find current or even future users,
no one responded to the call for interest in the RFC 4148
registry during the second half of 2010."
The current approach learns from this by tightly defining each entry
in the registry with only a few parameters open, if any. The idea is
that entries in the registry represent different measurement methods
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which require input parameters to set factors like source and
destination addresses (which do not change the fundamental nature of
the measurement). The downside of this approach is that it could
result in a large number of entries in the registry. We believe that
less is more in this context - it is better to have a reduced set of
useful metrics rather than a large set of metrics with questionable
usefulness. Therefore this document defines that the registry only
includes metrics that are well defined and that have proven to be
operationally useful. In order to guarantee these two
characteristics we require that a set of experts review the
allocation request to verify that the metric is well defined and it
is operationally useful.
6.1. Why this Attempt Will Succeed?
The registry defined in this document addresses the main issues
identified in the previous attempt. As we mention in the previous
section, one of the main issues with the previous registry was that
the metrics contained in the registry were too generic to be useful.
In this registry, the registry requests are evaluated by an expert
group that will make sure that the metric is properly defined. This
document provides guidelines to assess if a metric is properly
defined.
Another key difference between this attempt and the previous one is
that in this case there is at least one clear user for the registry:
the LMAP framework and protocol. Because the LMAP protocol will use
the registry values in its operation, this actually helps to
determine if a metric is properly defined. In particular, since we
expect that the LMAP control protocol will enable a controller to
request a measurement agent to perform a measurement using a given
metric by embedding the metric registry value in the protocol, a
metric is properly specified if it is defined well-enough so that it
is possible (and practical) to implement the metric in the
measurement agent. This was clearly not the case for the previous
attempt: defining a metric with an undefined P-Type makes its
implementation unpractical.
7. Common Columns of the Performance Metric Registry
The metric registry is composed of two sub-registries: the registry
for active performance metrics and the registry for passive
performance metrics. The rationale for having two sub-registries (as
opposed to having a single registry for all metrics) is because the
set of registry columns must support unambiguous registry entries,
and there are fundamental differences in the methods to collect
active and passive metrics and the required input parameters.
Forcing them into a single, generalized registry would result in a
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less meaningful structure for some entries in the registry.
Nevertheless, it is desirable that the two sub-registries share the
same structure as much as possible. In particular, both registries
will share the following columns: the identifier and the name, the
requester, the revision, the revision date and the description. All
these fields are described below. The design of these two sub-
registries is work-in-progress.
7.1. Performance Metrics Identifier
A numeric identifier for the Registered Performance Metric. This
identifier must be unique within the Performance Metric Registry and
sub-registries.
The Registered Performance Metric unique identifier is a 16-bit
integer (range 0 to 65535). When adding newly Registered Performance
Metrics to the Performance Metric Registry, IANA should assign the
lowest available identifier to the next active monitoring Registered
Performance Metric, and the highest available identifier to the next
passive monitoring Registered Performance Metric.
7.2. Performance Metrics Name
As the name of a Registered Performance Metric is the first thing a
potential implementor will use when determining whether it is
suitable for a given application, it is important to be as precise
and descriptive as possible. Names of Registered Performance
Metrics:
1. "must be chosen carefully to describe the Registered Performance
Metric and the context in which it will be used."
2. "should be unique within the Performance Metric Registry
(including sub-registries)."
3. "must use capital letters for the first letter of each component
. All other letters are lowercase, even for acronyms. Exceptions
are made for acronyms containing a mixture of lowercase and
capital letters, such as 'IPv4' and 'IPv6'."
4. "must use '_' between each component composing the Registered
Performance Metric name."
5. "must start with prefix Act_ for active measurement Registered
Performance Metric."
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6. "must start with prefix Pass_ for passive monitoring Registered
Performance Metric." AL COMMENTS: how about just 3 letters for
consistency: "Pas_"
7. MARCELO: I am uncertain whether we should give more guidance here
for the naming convention. In particular, the second component
could be the highest protocol used in the metric (e.g. UDP, TCP,
DNS, SIP, ICMP, IPv4, etc). the third component should be a
descriptive name (like latency, packet loss or similar). the
fourth component could be stream distribution. the fifth
component could be the output type (99mean, 95interval). this is
of course very active metric oriented, would be good if we could
figure out what is the minimum common structure for both passive
and active. TBD. AL COMMENTS: Let's see some examples for
passive monitoring. It may not make sense to have common name
components, except for Act_ and Pas_.
8. BENOIT proposes (approximately this, Al's wording) : The
remaining rules for naming are left to the Performance Experts to
determine as they gather experience, so this is an area of
planned update by a future RFC.
An example is "Act_UDP_Latency_Poisson_99mean" for a active
monitoring UDP latency metric using a Poisson stream of packets and
producing the 99th percentile mean as output.
>>>> NEED passive naming examples.
7.3. Performance Metrics Status
The status of the specification of this Registered Performance
Metric. Allowed values are 'current' and 'deprecated'. All newly
defined Information Elements have 'current' status.
7.4. Performance Metrics Requester
The requester for the Registered Performance Metric. The requester
may be a document, such as RFC, or person.
7.5. Performance Metrics Revision
The revision number of a Registered Performance Metric, starting at 0
for Registered Performance Metrics at time of definition and
incremented by one for each revision.
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7.6. Performance Metrics Revision Date
The date of acceptance or the most recent revision for the Registered
Performance Metric.
7.7. Performance Metrics Description
A Registered Performance Metric Description is a written
representation of a particular registry entry. It supplements the
metric name to help registry users select relevant Registered
Performance Metrics.
7.8. Reference Specification(s)
Registry entries that follow the common columns must provide the
reference specification(s) on which the Registered Performance Metric
is based.
8. The Life-Cycle of Registered Metrics
Once a Performance Metric or set of Performance Metrics has been
identified for a given application, candidate registry entry
specifications in accordance with Section X are submitted to IANA to
follow the process for review by the Performance Metric Experts, as
defined below. This process is also used for other changes to the
Performance Metric Registry, such as deprecation or revision, as
described later in this section.
It is also desirable that the author(s) of a candidate registry entry
seek review in the relevant IETF working group, or offer the
opportunity for review on the WG mailing list.
8.1. The Process for Review by the Performance Metric Experts
Requests to change Registered Metrics in the Performance Metric
Registry or a linked sub-registry are submitted to IANA, which
forwards the request to a designated group of experts (Performance
Metric Experts) appointed by the IESG; these are the reviewers called
for by the Expert Review RFC5226 policy defined for the Performance
Metric Registry. The Performance Metric Experts review the request
for such things as compliance with this document, compliance with
other applicable Performance Metric-related RFCs, and consistency
with the currently defined set of Registered Performance Metrics.
Authors are expected to review compliance with the specifications in
this document to check their submissions before sending them to IANA.
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The Performance Metric Experts should endeavor to complete referred
reviews in a timely manner. If the request is acceptable, the
Performance Metric Experts signify their approval to IANA, which
changes the Performance Metric Registry. If the request is not
acceptable, the Performance Metric Experts can coordinate with the
requester to change the request to be compliant. The Performance
Metric Experts may also choose in exceptional circumstances to reject
clearly frivolous or inappropriate change requests outright.
This process should not in any way be construed as allowing the
Performance Metric Experts to overrule IETF consensus. Specifically,
any Registered Metrics that were added with IETF consensus require
IETF consensus for revision or deprecation.
Decisions by the Performance Metric Experts may be appealed as in
Section 7 of RFC5226.
8.2. Revising Registered Performance Metrics
Requests to revise the Performance Metric Registry or a linked sub-
registry are submitted to IANA, which forwards the request to a
designated group of experts (Performance Metric Experts) appointed by
the IESG; these are the reviewers called for by the Expert Review
[RFC5226] policy defined for the Performance Metric Registry. The
Performance Metric Experts review the request for such things as
compliance with this document, compliance with other applicable
Performance Metric-related RFCs, and consistency with the currently
defined set of Registered Performance Metrics.
A request for Revision is ONLY permissible when the changes maintain
backward-compatibility with implementations of the prior registry
entry describing a Registered Metric (entries with lower revision
numbers, but the same Identifier and Name).
The purpose of the Status field in the Performance Metric Registry is
to indicate whether the entry for a Registered Metric is 'current' or
'deprecated'.
In addition, no policy is defined for revising IANA Performance
Metric entries or addressing errors therein. To be certain, changes
and deprecations within the Performance Metric Registry are not
encouraged, and should be avoided to the extent possible. However,
in recognition that change is inevitable, the provisions of this
section address the need for revisions.
Revisions are initiated by sending a candidate Registered Performance
Metric definition to IANA, as in Section X, identifying the existing
registry entry.
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The primary requirement in the definition of a policy for managing
changes to existing Registered Performance Metrics is avoidance of
interoperability problems; Performance Metric Experts must work to
maintain interoperability above all else. Changes to Registered
Performance Metrics already in use may only be done in an inter-
operable way; necessary changes that cannot be done in a way to allow
interoperability with unchanged implementations must result in
deprecation of the earlier metric.
A change to a Registered Performance Metric is held to be backward-
compatible only when:
1. "it involves the correction of an error that is obviously only
editorial; or"
2. "it corrects an ambiguity in the Registered Performance Metric's
definition, which itself leads to issues severe enough to prevent
the Registered Performance Metric's usage as originally defined;
or"
3. "it corrects missing information in the metric definition without
changing its meaning (e.g., the explicit definition of 'quantity'
semantics for numeric fields without a Data Type Semantics
value); or"
4. "it harmonizes with an external reference that was itself
corrected."
5. "BENOIT: NOTE THAT THERE ARE MORE RULES IN RFC 7013 SECTION 5 BUT
THEY WOULD ONLY APPLY TO THE ACTIVE/PASSIVE DRAFTS. TO BE
DISCUSSED."
If a change is deemed permissible by the Performance Metric Experts,
IANA makes the change in the Performance Metric Registry. The
requester of the change is appended to the requester in the registry.
Each Registered Performance Metric in the Registry has a revision
number, starting at zero. Each change to a Registered Performance
Metric following this process increments the revision number by one.
COMMENT: Al (and Phil) think we should keep old/revised entries as-
is, marked as deprecated >>>> Since any revision must be inter-
operable according to the criteria above, there is no need for the
Performance Metric Registry to store information about old revisions.
When a revised Registered Performance Metric is accepted into the
Performance Metric Registry, the date of acceptance of the most
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recent revision is placed into the revision Date column of the
registry for that Registered Performance Metric.
Where applicable, additions to registry entries in the form of text
Comments or Remarks should include the date, but such additions may
not constitute a revision according to this process.
8.3. Deprecating Registered Performance Metrics
Changes that are not permissible by the above criteria for Registered
Metric's revision may only be handled by deprecation. A Registered
Performance Metric MAY be deprecated and replaced when:
1. "the Registered Performance Metric definition has an error or
shortcoming that cannot be permissibly changed as in
Section Revising Registered Performance Metrics; or"
2. "the deprecation harmonizes with an external reference that was
itself deprecated through that reference's accepted deprecation
method; or"
A request for deprecation is sent to IANA, which passes it to the
Performance Metric Expert for review, as in Section 'The Process for
Review by the Performance Metric Experts'. When deprecating an
Performance Metric, the Performance Metric description in the
Performance Metric Registry must be updated to explain the
deprecation, as well as to refer to any new Performance Metrics
created to replace the deprecated Performance Metric.
The revision number of a Registered Performance Metric is incremented
upon deprecation, and the revision Date updated, as with any
revision.
The use of deprecated Registered Metrics should result in a log entry
or human-readable warning by the respective application.
Names and Metric ID of deprecated Registered Metrics must not be
reused.
9. Performance Metric Registry and other Registries
BENOIT: TBD.
THE BASIC IDEA IS THAT PEOPLE COULD DIRECTLY DEFINE PERF. METRICS IN
OTHER EXISTING REGISTRIES, FOR SPECIFIC PROTOCOL/ENCODING. EXAMPLE:
IPFIX. IDEALLY, ALL PERF. METRICS SHOULD BE DEFINED IN THIS
REGISTRY AND REFERS TO FROM OTHER REGISTRIES.
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10. Security considerations
This draft doesn't introduce any new security considerations for the
Internet. However, the definition of Performance Metrics may
introduce some security concerns, and should be reviewed with
security in mind.
11. IANA Considerations
This document specifies the procedure for Performance Metrics
Registry setup. IANA is requested to create a new registry for
performance metrics called "Registered Performance Metrics".
This Performance Metrics Registry contains two sub registries once
for active and another one for passive performance metrics. These
sub registries are not defined in this document. However, these two
sub registries MUST contain the following columns: the identifier and
the name, the requester, the revision, the revision date and the
description, as specified in this document.
New assignments for Performance Metric Registry will be administered
by IANA through Expert Review [RFC5226], i.e., review by one of a
group of experts, the Performance Metric Experts, appointed by the
IESG upon recommendation of the Transport Area Directors. The
experts will initially be drawn from the Working Group Chairs and
document editors of the Performance Metrics Directorate [performance-
metrics-directorate].
12. Acknowledgments
Thanks to Brian Trammell and Bill Cerveny, IPPM chairs, for leading
some brainstorming sessions on this topic.
13. References
13.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996.
[RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis,
"Framework for IP Performance Metrics", RFC 2330, May
1998.
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[RFC4148] Stephan, E., "IP Performance Metrics (IPPM) Metrics
Registry", BCP 108, RFC 4148, August 2005.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC6248] Morton, A., "RFC 4148 and the IP Performance Metrics
(IPPM) Registry of Metrics Are Obsolete", RFC 6248, April
2011.
[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New
Performance Metric Development", BCP 170, RFC 6390,
October 2011.
[RFC6576] Geib, R., Morton, A., Fardid, R., and A. Steinmitz, "IP
Performance Metrics (IPPM) Standard Advancement Testing",
BCP 176, RFC 6576, March 2012.
13.2. Informative References
[RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control
Protocol Extended Reports (RTCP XR)", RFC 3611, November
2003.
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Jacobson, "RTP: A Transport Protocol for Real-Time
Applications", STD 64, RFC 3550, July 2003.
[RFC6035] Pendleton, A., Clark, A., Johnston, A., and H. Sinnreich,
"Session Initiation Protocol Event Package for Voice
Quality Reporting", RFC 6035, November 2010.
[I-D.ietf-lmap-framework]
Eardley, P., Morton, A., Bagnulo, M., Burbridge, T.,
Aitken, P., and A. Akhter, "A framework for large-scale
measurement platforms (LMAP)", draft-ietf-lmap-
framework-03 (work in progress), January 2014.
Authors' Addresses
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Marcelo Bagnulo
Universidad Carlos III de Madrid
Av. Universidad 30
Leganes, Madrid 28911
SPAIN
Phone: 34 91 6249500
Email: marcelo@it.uc3m.es
URI: http://www.it.uc3m.es
Benoit Claise
Cisco Systems, Inc.
De Kleetlaan 6a b1
1831 Diegem
Belgium
Email: bclaise@cisco.com
Philip Eardley
British Telecom
Adastral Park, Martlesham Heath
Ipswich
ENGLAND
Email: philip.eardley@bt.com
Al Morton
AT&T Labs
200 Laurel Avenue South
Middletown, NJ
USA
Email: acmorton@att.com
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