Internet DRAFT - draft-ietf-ippm-metric-registry
draft-ietf-ippm-metric-registry
Network Working Group M. Bagnulo
Internet-Draft UC3M
Intended status: Standards Track B. Claise
Expires: September 10, 2020 Cisco Systems, Inc.
P. Eardley
BT
A. Morton
AT&T Labs
A. Akhter
Consultant
March 9, 2020
Registry for Performance Metrics
draft-ietf-ippm-metric-registry-24
Abstract
This document defines the format for the IANA Performance Metrics
Registry. This document also gives a set of guidelines for
Registered Performance Metric requesters and reviewers.
Status of This Memo
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This Internet-Draft will expire on September 10, 2020.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Motivation for a Performance Metrics Registry . . . . . . . . 8
4.1. Interoperability . . . . . . . . . . . . . . . . . . . . 8
4.2. Single point of reference for Performance Metrics . . . . 9
4.3. Side benefits . . . . . . . . . . . . . . . . . . . . . . 9
5. Criteria for Performance Metrics Registration . . . . . . . . 9
6. Performance Metric Registry: Prior attempt . . . . . . . . . 10
6.1. Why this Attempt Should Succeed . . . . . . . . . . . . . 11
7. Definition of the Performance Metric Registry . . . . . . . . 11
7.1. Summary Category . . . . . . . . . . . . . . . . . . . . 13
7.1.1. Identifier . . . . . . . . . . . . . . . . . . . . . 13
7.1.2. Name . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1.3. URI . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1.4. Description . . . . . . . . . . . . . . . . . . . . . 17
7.1.5. Reference . . . . . . . . . . . . . . . . . . . . . . 17
7.1.6. Change Controller . . . . . . . . . . . . . . . . . . 17
7.1.7. Version (of Registry Format) . . . . . . . . . . . . 18
7.2. Metric Definition Category . . . . . . . . . . . . . . . 18
7.2.1. Reference Definition . . . . . . . . . . . . . . . . 18
7.2.2. Fixed Parameters . . . . . . . . . . . . . . . . . . 18
7.3. Method of Measurement Category . . . . . . . . . . . . . 19
7.3.1. Reference Method . . . . . . . . . . . . . . . . . . 19
7.3.2. Packet Stream Generation . . . . . . . . . . . . . . 19
7.3.3. Traffic Filter . . . . . . . . . . . . . . . . . . . 20
7.3.4. Sampling Distribution . . . . . . . . . . . . . . . . 20
7.3.5. Run-time Parameters . . . . . . . . . . . . . . . . . 21
7.3.6. Role . . . . . . . . . . . . . . . . . . . . . . . . 22
7.4. Output Category . . . . . . . . . . . . . . . . . . . . . 22
7.4.1. Type . . . . . . . . . . . . . . . . . . . . . . . . 22
7.4.2. Reference Definition . . . . . . . . . . . . . . . . 23
7.4.3. Metric Units . . . . . . . . . . . . . . . . . . . . 23
7.4.4. Calibration . . . . . . . . . . . . . . . . . . . . . 23
7.5. Administrative information . . . . . . . . . . . . . . . 24
7.5.1. Status . . . . . . . . . . . . . . . . . . . . . . . 24
7.5.2. Requester . . . . . . . . . . . . . . . . . . . . . . 24
7.5.3. Revision . . . . . . . . . . . . . . . . . . . . . . 24
7.5.4. Revision Date . . . . . . . . . . . . . . . . . . . . 24
7.6. Comments and Remarks . . . . . . . . . . . . . . . . . . 24
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8. Processes for Managing the Performance Metric Registry Group 24
8.1. Adding new Performance Metrics to the Performance Metrics
Registry . . . . . . . . . . . . . . . . . . . . . . . . 25
8.2. Revising Registered Performance Metrics . . . . . . . . . 26
8.3. Deprecating Registered Performance Metrics . . . . . . . 28
9. Security considerations . . . . . . . . . . . . . . . . . . . 28
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29
10.1. Registry Group . . . . . . . . . . . . . . . . . . . . . 29
10.2. Performance Metric Name Elements . . . . . . . . . . . . 29
10.3. New Performance Metrics Registry . . . . . . . . . . . . 30
11. Blank Registry Template . . . . . . . . . . . . . . . . . . . 32
11.1. Summary . . . . . . . . . . . . . . . . . . . . . . . . 32
11.1.1. ID (Identifier) . . . . . . . . . . . . . . . . . . 32
11.1.2. Name . . . . . . . . . . . . . . . . . . . . . . . . 32
11.1.3. URI . . . . . . . . . . . . . . . . . . . . . . . . 32
11.1.4. Description . . . . . . . . . . . . . . . . . . . . 32
11.1.5. Change Controller . . . . . . . . . . . . . . . . . 32
11.1.6. Version (of Registry Format) . . . . . . . . . . . . 32
11.2. Metric Definition . . . . . . . . . . . . . . . . . . . 32
11.2.1. Reference Definition . . . . . . . . . . . . . . . . 32
11.2.2. Fixed Parameters . . . . . . . . . . . . . . . . . . 32
11.3. Method of Measurement . . . . . . . . . . . . . . . . . 33
11.3.1. Reference Method . . . . . . . . . . . . . . . . . . 33
11.3.2. Packet Stream Generation . . . . . . . . . . . . . . 33
11.3.3. Traffic Filtering (observation) Details . . . . . . 33
11.3.4. Sampling Distribution . . . . . . . . . . . . . . . 33
11.3.5. Run-time Parameters and Data Format . . . . . . . . 33
11.3.6. Roles . . . . . . . . . . . . . . . . . . . . . . . 33
11.4. Output . . . . . . . . . . . . . . . . . . . . . . . . . 33
11.4.1. Type . . . . . . . . . . . . . . . . . . . . . . . . 34
11.4.2. Reference Definition . . . . . . . . . . . . . . . . 34
11.4.3. Metric Units . . . . . . . . . . . . . . . . . . . . 34
11.4.4. Calibration . . . . . . . . . . . . . . . . . . . . 34
11.5. Administrative items . . . . . . . . . . . . . . . . . . 34
11.5.1. Status . . . . . . . . . . . . . . . . . . . . . . . 34
11.5.2. Requester . . . . . . . . . . . . . . . . . . . . . 34
11.5.3. Revision . . . . . . . . . . . . . . . . . . . . . . 34
11.5.4. Revision Date . . . . . . . . . . . . . . . . . . . 34
11.6. Comments and Remarks . . . . . . . . . . . . . . . . . . 34
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 34
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 35
13.1. Normative References . . . . . . . . . . . . . . . . . . 35
13.2. Informative References . . . . . . . . . . . . . . . . . 36
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37
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1. Introduction
The IETF specifies and uses Performance Metrics of protocols and
applications transported over its protocols. Performance metrics are
important part of network operations using IETF protocols, and
[RFC6390] specifies guidelines for their development.
The definition and use of Performance Metrics in the IETF has been
fostered 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 "Benchmarking Methodology" WG (BMWG) defines many Performance
Metrics for use in laboratory benchmarking of inter-networking
technologies.
The "Metric Blocks for use with RTCP's Extended Report Framework"
(XRBLOCK) WG (concluded) 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 "IP Flow Information eXport" (IPFIX) concluded WG specified an
IANA process for new Information Elements. Some Performance
Metrics related Information Elements are proposed on regular
basis.
The "Performance Metrics for Other Layers" (PMOL) a 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.
Despite the importance of Performance Metrics, there are two related
problems for the industry. First, ensuring 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, discovering which Performance Metrics have been specified, to
avoid developing a new Performance Metric that is very similar, but
not quite inter-operable. These problems can be addressed by
creating a registry of performance metrics. The usual way in which
the IETF organizes registries is with Internet Assigned Numbers
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Authority (IANA), and there is currently no Performance Metrics
Registry maintained by the IANA.
This document requests that IANA create and maintain a Performance
Metrics Registry, according to the maintenance procedures and the
Performance Metrics Registry format defined in this memo. The
resulting Performance Metrics Registry is for use by the IETF and
others. Although the Registry formatting specifications herein are
primarily for registry creation by IANA, any other organization that
wishes to create a performance metrics registry may use the same
formatting specifications for their purposes. The authors make no
guarantee of the registry format's applicability to any possible set
of Performance Metrics envisaged by other organizations, but
encourage others to apply it. In the remainder of this document,
unless we explicitly say otherwise, we will refer to the IANA-
maintained Performance Metrics Registry as simply the Performance
Metrics Registry.
2. 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 BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Performance Metric: A Performance Metric is a quantitative measure
of performance, targeted to an IETF-specified protocol or targeted
to an application transported over an IETF-specified protocol.
Examples of Performance Metrics are the FTP response time for a
complete file download, the DNS response time to resolve the IP
address(es), a database logging time, etc. This definition is
consistent with the definition of metric in [RFC2330] and broader
than the definition of performance metric in [RFC6390].
Registered Performance Metric: A Registered Performance Metric is a
Performance Metric expressed as an entry in the Performance
Metrics Registry, administered by IANA. Such a performance metric
has met all the registry review criteria defined in this document
in order to be included in the registry.
Performance Metrics Registry: The IANA registry containing
Registered Performance Metrics.
Proprietary Registry: A set of metrics that are registered in a
proprietary registry, as opposed to Performance Metrics Registry.
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Performance Metrics Experts: The Performance Metrics Experts is a
group of designated experts [RFC8126] selected by the IESG to
validate the Performance Metrics before updating the Performance
Metrics Registry. The Performance Metrics Experts work closely
with IANA.
Parameter: A Parameter is an input factor defined as a variable in
the definition of a Performance Metric. A Parameter is a
numerical or other specified factor forming one of a set that
defines a metric or sets the conditions of its operation. All
Parameters must be known in order to make a measurement using a
metric and interpret the results. There are two types of
Parameters: Fixed and Run-time parameters. For the Fixed
Parameters, the value of the variable is specified in the
Performance Metrics Registry entry and different Fixed Parameter
values results in different Registered Performance Metrics. For
the Run-time Parameters, the value of the variable is defined when
the metric measurement method is executed and a given Registered
Performance Metric supports multiple values for the parameter.
Although Run-time Parameters do not change the fundamental nature
of the Performance Metric's definition, some have substantial
influence on the network property being assessed and
interpretation of the results.
Note: Consider the case of packet loss in the following two
Active Measurement Method cases. The first case is packet loss
as background loss where the Run-time Parameter set includes a
very sparse Poisson stream, and only characterizes the times
when packets were lost. Actual user streams likely see much
higher loss at these times, due to tail drop or radio errors.
The second case is packet loss as inverse of throughput where
the Run-time Parameter set includes a very dense, bursty
stream, and characterizes the loss experienced by a stream that
approximates a user stream. These are both "loss metrics", but
the difference in interpretation of the results is highly
dependent on the Run-time Parameters (at least), to the extreme
where we are actually using loss to infer its compliment:
delivered throughput.
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. The complete definition of Active Methods is
specified in section 3.4 of[RFC7799]. Examples of Active
Measurement Methods are the measurement methods for the One way
delay metric defined in [RFC7679] and the one for round trip delay
defined in [RFC2681].
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Passive Measurement Method: Methods of Measurement conducted on
network traffic, generated either from the end users or from
network elements that would exist regardless whether the
measurement was being conducted or not. The complete definition
of Passive Methods is specified in section 3.6 of [RFC7799]. One
characteristic of Passive Measurement Methods is that sensitive
information may be observed, and as a consequence, stored in the
measurement system.
Hybrid Measurement Method: Hybrid Methods are Methods of Measurement
that use a combination of Active Methods and Passive Methods, to
assess Active Metrics, Passive Metrics, or new metrics derived
from the a priori knowledge and observations of the stream of
interest. The complete definition of Hybrid Methods is specified
in section 3.8 of [RFC7799].
3. Scope
This document is intended for two different audiences:
1. For those defining new Registered Performance Metrics, it
provides specifications and best practices to be used in deciding
which Registered Performance Metrics are useful for a measurement
study, instructions for writing the text for each column of the
Registered Performance Metrics, and information on the supporting
documentation required for the new Performance Metrics Registry
entry (up to and including the publication of one or more
immutable documents such as an RFC).
2. For the appointed Performance Metrics Experts and for IANA
personnel administering the new IANA Performance Metrics
Registry, it defines a set of acceptance criteria against which
these proposed Registered Performance Metrics should be
evaluated.
In addition, this document may be useful for other organizations who
are defining a Performance Metric registry of their own, and may re-
use the features of the Performance Metrics Registry defined in this
document.
This Performance Metrics Registry is applicable to Performance
Metrics issued from Active Measurement, Passive Measurement, and any
other form of Performance Metric. This registry is designed to
encompass Performance Metrics developed throughout the IETF and
especially for the technologies specified in the following working
groups: IPPM, XRBLOCK, IPFIX, and BMWG. This document analyzes a
prior attempt to set up a Performance Metrics Registry, and the
reasons why this design was inadequate [RFC6248]. Finally, this
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document gives a set of guidelines for requesters and expert
reviewers of candidate Registered Performance Metrics.
This document makes no attempt to populate the Performance Metrics
Registry with initial entries; the related memo
[I-D.ietf-ippm-initial-registry] proposes the initial set of regsitry
entries.
4. Motivation for a Performance Metrics Registry
In this section, we detail several motivations for the Performance
Metrics Registry.
4.1. Interoperability
As with any IETF registry, the primary intention is to manage
registration of identifiers for use within one or more protocols. In
the particular case of the Performance Metrics Registry, there are
two types of protocols that will use the Performance Metrics in the
Performance Metrics Registry during their operation (by referring to
the Index values):
o Control protocol: This type of protocol used to allow one entity
to request another entity to perform a measurement using a
specific metric defined by the Performance Metrics Registry. One
particular example is the LMAP framework [RFC7594]. Using the
LMAP terminology, the Performance Metrics Registry is used in the
LMAP Control protocol to allow a Controller to schedule a
measurement task for one or more Measurement Agents. In order to
enable this use case, the entries of the Performance Metrics
Registry must be sufficiently defined to allow a Measurement Agent
implementation to trigger a specific measurement task upon the
reception of a control protocol message. This requirement heavily
constrains the type of entries that are acceptable for the
Performance Metrics Registry.
o Report protocol: This type of protocol is used to allow an entity
to report measurement results to another entity. By referencing
to a specific Performance Metrics Registry, it is possible to
properly characterize the measurement result data being reported.
Using the LMAP terminology, the Performance Metrics Registry is
used in the Report protocol to allow a Measurement Agent to report
measurement results to a Collector.
It should be noted that the LMAP framework explicitly allows for
using not only the IANA-maintained Performance Metrics Registry but
also other registries containing Performance Metrics, either defined
by other organizations or private ones. However, others who are
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creating Registries to be used in the context of an LMAP framework
are encouraged to use the Registry format defined in this document,
because this makes it easier for developers of LMAP Measurement
Agents (MAs) to programmatically use information found in those other
Registries' entries.
4.2. Single point of reference for Performance Metrics
A Performance Metrics Registry 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 Performance
Metrics that attempt to measure the same phenomena but in slightly
different (and incompatible) ways. Having a registry would allow the
IETF community and others 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 Performance Metrics, where different entities
that request measurements, execute measurements, and report the
results can benefit from a common understanding of the referenced
Performance Metric.
4.3. Side benefits
There are a couple of side benefits of having such a registry.
First, the Performance Metrics Registry could serve as an inventory
of useful and used Performance Metrics, that are normally supported
by different implementations of measurement agents. Second, the
results of measurements using the Performance Metrics should be
comparable even if they are performed by different implementations
and in different networks, as the Performance 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 Registered Performance Metrics are sufficiently well
specified to result in comparable (or equivalent) results.
Registered Performance Metrics which have undergone such testing
SHOULD be noted, with a reference to the test results.
5. Criteria for Performance Metrics Registration
It is neither possible nor desirable to populate the Performance
Metrics Registry with all combinations of Parameters of all
Performance Metrics. The Registered Performance Metrics SHOULD be:
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1. interpretable by the user.
2. implementable by the software or hardware designer,
3. deployable by network operators,
4. accurate in terms of producing equivalent results, and for
interoperability and deployment across vendors,
5. Operationally useful, so that it has significant industry
interest and/or has seen deployment,
6. Sufficiently tightly defined, so that different values for the
Run-time Parameters does not change the fundamental nature of the
measurement, nor change the practicality of its implementation.
In essence, there needs to be evidence that a candidate Registered
Performance Metric has significant industry interest, or has seen
deployment, and there is agreement that the candidate Registered
Performance Metric serves its intended purpose.
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 [RFC6248]
might help to 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
Registered Performance Metric with only a few variable (Run-time)
Parameters to be specified by the measurement designer, if any. The
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idea is that entries in the Performance Metrics Registry stem from
different measurement methods which require input (Run-time)
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 Performance Metrics Registry. There is agreement
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, some with
with questionable usefulness.
6.1. Why this Attempt Should Succeed
As mentioned 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. This document specifies stricter criteria
for performance metric registration (see section 5), and imposes a
group of Performance Metrics Experts that will provide guidelines to
assess if a Performance Metric is properly specified.
Another key difference between this attempt and the previous one is
that in this case there is at least one clear user for the
Performance Metrics Registry: the LMAP framework and protocol.
Because the LMAP protocol will use the Performance Metrics 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
Performance Metrics Registry identifier in the protocol. Such a
metric and method are properly specified if they are defined well-
enough so that it is possible (and practical) to implement them in
the measurement agent. This was the failure of the previous attempt:
a registry entry with an undefined Type-P (section 13 of RFC 2330
[RFC2330]) allows implementation to be ambiguous.
7. Definition of the Performance Metric Registry
This Performance Metrics Registry is applicable to Performance
Metrics used for Active Measurement, Passive Measurement, and any
other form of Performance Measurement. Each category of measurement
has unique properties, so some of the columns defined below are not
applicable for a given metric category. In this case, the column(s)
SHOULD be populated with the "NA" value (Non Applicable). However,
the "NA" value MUST NOT be used by any metric in the following
columns: Identifier, Name, URI, Status, Requester, Revision, Revision
Date, Description. In the future, a new category of metrics could
require additional columns, and adding new columns is a recognized
form of registry extension. The specification defining the new
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column(s) MUST give general guidelines for populating the new
column(s) for existing entries.
The columns of the Performance Metrics Registry are defined below.
The columns are grouped into "Categories" to facilitate the use of
the registry. Categories are described at the 7.x heading level, and
columns are at the 7.x.y heading level. The Figure below illustrates
this organization. An entry (row) therefore gives a complete
description of a Registered Performance Metric.
Each column serves as a check-list item and helps to avoid omissions
during registration and expert review.
=======================================================================
Legend:
Registry Categories and Columns are shown below as:
Category
------------------...
Column | Column |...
=======================================================================
Summary
------------------------------------------------------------------------
Identifier | Name | URI | Desc. | Reference | Change Controller | Ver |
Metric Definition
-----------------------------------------
Reference Definition | Fixed Parameters |
Method of Measurement
---------------------------------------------------------------------
Reference | Packet | Traffic | Sampling | Run-time | Role |
Method | Stream | Filter | Distribution | Parameters | |
| Generation |
Output
-----------------------------------------
Type | Reference | Units | Calibration |
| Definition | | |
Administrative Information
------------------------------------
Status |Requester | Rev | Rev.Date |
Comments and Remarks
--------------------
There is a blank template of the Registry template provided in
Section 11 of this memo.
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7.1. Summary Category
7.1.1. Identifier
A numeric identifier for the Registered Performance Metric. This
identifier MUST be unique within the Performance Metrics Registry.
The Registered Performance Metric unique identifier is an unbounded
integer (range 0 to infinity).
The Identifier 0 should be Reserved. The Identifier values from
64512 to 65536 are reserved for private or experimental use, and the
user may encounter overlapping uses.
When adding newly Registered Performance Metrics to the Performance
Metrics Registry, IANA SHOULD assign the lowest available identifier
to the new Registered Performance Metric.
If a Performance Metrics Expert providing review determines that
there is a reason to assign a specific numeric identifier, possibly
leaving a temporary gap in the numbering, then the Performance Expert
SHALL inform IANA of this decision.
7.1.2. Name
As the name of a Registered Performance Metric is the first thing a
potential human implementor will use when determining whether it is
suitable for their measurement study, it is important to be as
precise and descriptive as possible. In future, users will review
the names to determine if the metric they want to measure has already
been registered, or if a similar entry is available as a basis for
creating a new entry.
Names are composed of the following elements, separated by an
underscore character "_":
MetricType_Method_SubTypeMethod_... Spec_Units_Output
o MetricType: a combination of the directional properties and the
metric measured, such as and not limited to:
RTDelay (Round Trip Delay)
RTDNS (Response Time Domain Name Service)
RLDNS (Response Loss Domain Name Service)
OWDelay (One Way Delay)
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RTLoss (Round Trip Loss)
OWLoss (One Way Loss)
OWPDV (One Way Packet Delay Variation)
OWIPDV (One Way Inter-Packet Delay Variation)
OWReorder (One Way Packet Reordering)
OWDuplic (One Way Packet Duplication)
OWBTC (One Way Bulk Transport Capacity)
OWMBM (One Way Model Based Metric)
SPMonitor (Single Point Monitor)
MPMonitor (Multi-Point Monitor)
o Method: One of the methods defined in [RFC7799], such as and not
limited to:
Active (depends on a dedicated measurement packet stream and
observations of the stream)
Passive (depends *solely* on observation of one or more
existing packet streams)
HybridType1 (observations on one stream that combine both
active and passive methods)
HybridType2 (observations on two or more streams that combine
both active and passive methods)
Spatial (Spatial Metric of RFC5644)
o SubTypeMethod: One or more sub-types to further describe the
features of the entry, such as and not limited to:
ICMP (Internet Control Message Protocol)
IP (Internet Protocol)
DSCPxx (where xx is replaced by a Diffserv code point)
UDP (User Datagram Protocol)
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TCP (Transport Control Protocol)
QUIC (QUIC transport protocol)
HS (Hand-Shake, such as TCP's 3-way HS)
Poisson (Packet generation using Poisson distribution)
Periodic (Periodic packet generation)
SendOnRcv (Sender keeps one packet in-transit by sending when
previous packet arrives)
PayloadxxxxB (where xxxx is replaced by an integer, the number
of octets in the Payload))
SustainedBurst (Capacity test, worst case)
StandingQueue (test of bottleneck queue behavior)
SubTypeMethod values are separated by a hyphen "-" character,
which indicates that they belong to this element, and that their
order is unimportant when considering name uniqueness.
o Spec: An immutable document identifier combined with a document
section identifier. For RFCs, this consists of the RFC number and
major section number that specifies this Registry entry in the
form RFCXXXXsecY, such as RFC7799sec3. Note: the RFC number is
not the Primary Reference specification for the metric definition,
such as [RFC7679] for One-way Delay; it will contain the
placeholder "RFCXXXXsecY" until the RFC number is assigned to the
specifying document, and would remain blank in private registry
entries without a corresponding RFC. Anticipating the "RFC10K"
problem, the number of the RFC continues to replace RFCXXXX
regardless of the number of digits in the RFC number.
Anticipating Registry Entries from other standards bodies, the
form of this Name Element MUST be proposed and reviewed for
consistency and uniqueness by the Expert Reviewer.
o Units: The units of measurement for the output, such as and not
limited to:
Seconds
Ratio (unitless)
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Percent (value multiplied by 100%)
Logical (1 or 0)
Packets
BPS (Bits per Second)
PPS (Packets per Second)
EventTotal (for unit-less counts)
Multiple (more than one type of unit)
Enumerated (a list of outcomes)
Unitless
o Output: The type of output resulting from measurement, such as and
not limited to:
Singleton
Raw (multiple Singletons)
Count
Minimum
Maximum
Median
Mean
95Percentile (95th Percentile)
99Percentile (99th Percentile)
StdDev (Standard Deviation)
Variance
PFI (Pass, Fail, Inconclusive)
FlowRecords (descriptions of flows observed)
LossRatio (lost packets to total packets, <=1)
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An example is:
RTDelay_Active_IP-UDP-Periodic_RFCXXXXsecY_Seconds_95Percentile
as described in section 4 of [I-D.ietf-ippm-initial-registry].
Note that private registries following the format described here
SHOULD use the prefix "Priv_" on any name to avoid unintended
conflicts (further considerations are described in section 10).
Private registry entries usually have no specifying RFC, thus the
Spec: element has no clear interpretation.
7.1.3. URI
The URIs column MUST contain a URL [RFC3986] that uniquely identifies
and locates the metric entry so it is accessible through the
Internet. The URL points to a file containing all the human-readable
information for one registry entry. The URL SHALL reference a target
file that is preferably HTML-formatted and contains URLs to
referenced sections of HTML-ized RFCs, or other reference
specifications. These target files for different entries can be more
easily edited and re-used when preparing new entries. The exact form
of the URL for each target file, and the target file itself, will be
determined by IANA and reside on "iana.org". The major sections of
[I-D.ietf-ippm-initial-registry] provide an example of a target file
in HTML form (sections 4 and higher).
7.1.4. Description
A Registered Performance Metric description is a written
representation of a particular Performance Metrics Registry entry.
It supplements the Registered Performance Metric name to help
Performance Metrics Registry users select relevant Registered
Performance Metrics.
7.1.5. Reference
This entry gives the specification containing the candidate registry
entry which was reviewed and agreed, if such an RFC or other
specification exists.
7.1.6. Change Controller
This entry names the entity responsible for approving revisions to
the registry entry, and SHALL provide contact information (for an
individual, where appropriate).
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7.1.7. Version (of Registry Format)
This entry gives the version number for the registry format used.
Formats complying with this memo MUST use 1.0. The version number
SHALL NOT change unless a new RFC is published that changes the
registry format. The version number of registry entries SHALL NOT
change unless the registry entry is updated (following procedures in
section 8).
7.2. Metric Definition Category
This category includes columns to prompt all necessary details
related to the metric definition, including the immutable document
reference and values of input factors, called fixed parameters, which
are left open in the immutable document, but have a particular value
defined by the performance metric.
7.2.1. Reference Definition
This entry provides a reference (or references) to the relevant
section(s) of the document(s) that define the metric, as well as any
supplemental information needed to ensure an unambiguous definition
for implementations. The reference needs to be an immutable
document, such as an RFC; for other standards bodies, it is likely to
be necessary to reference a specific, dated version of a
specification.
7.2.2. Fixed Parameters
Fixed Parameters are Parameters whose value must be specified in the
Performance Metrics Registry. The measurement system uses these
values.
Where referenced metrics supply a list of Parameters as part of their
descriptive template, a sub-set of the Parameters will be designated
as Fixed Parameters. As an example for active metrics, Fixed
Parameters determine most or all of the IPPM Framework convention
"packets of Type-P" as described in [RFC2330], such as transport
protocol, payload length, TTL, etc. An example for passive metrics
is for RTP packet loss calculation that relies on the validation of a
packet as RTP which is a multi-packet validation controlled by
MIN_SEQUENTIAL as defined by [RFC3550]. Varying MIN_SEQUENTIAL
values can alter the loss report and this value could be set as a
Fixed Parameter.
Parameters MUST have well-defined names. For human readers, the
hanging indent style is preferred, and any Parameter names and
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definitions that do not appear in the Reference Method Specification
MUST appear in this column (or Run-time Parameters column).
Parameters MUST have a well-specified data format.
A Parameter which is a Fixed Parameter for one Performance Metrics
Registry entry may be designated as a Run-time Parameter for another
Performance Metrics Registry entry.
7.3. Method of Measurement Category
This category includes columns for references to relevant sections of
the immutable document(s) and any supplemental information needed to
ensure an unambiguous method for implementations.
7.3.1. Reference Method
This entry provides references to relevant sections of immutable
documents, such as RFC(s) (for other standards bodies, it is likely
to be necessary to reference a specific, dated version of a
specification) describing the method of measurement, as well as any
supplemental information needed to ensure unambiguous interpretation
for implementations referring to the immutable document text.
Specifically, this section should include pointers to pseudocode or
actual code that could be used for an unambiguous implementation.
7.3.2. Packet Stream Generation
This column applies to Performance Metrics that generate traffic as
part of their Measurement Method, including but not necessarily
limited to Active metrics. The generated traffic is referred as a
stream and this column describes its characteristics.
Each entry for this column contains the following information:
o Value: The name of the packet stream scheduling discipline
o Reference: the specification where the parameters of the stream
are defined
The packet generation stream may require parameters such as the
average packet rate and distribution truncation value for streams
with Poisson-distributed inter-packet sending times. In case such
parameters are needed, they should be included either in the Fixed
parameter column or in the run time parameter column, depending on
whether they will be fixed or will be an input for the metric.
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The simplest example of stream specification is Singleton scheduling
(see [RFC2330]), where a single atomic measurement is conducted.
Each atomic measurement could consist of sending a single packet
(such as a DNS request) or sending several packets (for example, to
request a webpage). Other streams support a series of atomic
measurements in a "sample", with a schedule defining the timing
between each transmitted packet and subsequent measurement.
Principally, two different streams are used in IPPM metrics, Poisson
distributed as described in [RFC2330] and Periodic as described in
[RFC3432]. Both Poisson and Periodic have their own unique
parameters, and the relevant set of parameters names and values
should be included either in the Fixed Parameters column or in the
Run-time parameter column.
7.3.3. Traffic Filter
This column applies to Performance Metrics that observe packets
flowing through (the device with) the measurement agent i.e. that is
not necessarily addressed to the measurement agent. This includes
but is not limited to Passive Metrics. The filter specifies the
traffic that is measured. This includes protocol field values/
ranges, such as address ranges, and flow or session identifiers.
The traffic filter itself depends on needs of the metric itself and a
balance of an operator's measurement needs and a user's need for
privacy. Mechanics for conveying the filter criteria might be the
BPF (Berkley Packet Filter) or PSAMP [RFC5475] Property Match
Filtering which reuses IPFIX [RFC7012]. An example BPF string for
matching TCP/80 traffic to remote destination net 192.0.2.0/24 would
be "dst net 192.0.2.0/24 and tcp dst port 80". More complex filter
engines might be supported by the implementation that might allow for
matching using Deep Packet Inspection (DPI) technology.
The traffic filter includes the following information:
Type: the type of traffic filter used, e.g. BPF, PSAMP, OpenFlow
rule, etc. as defined by a normative reference
Value: the actual set of rules expressed
7.3.4. Sampling Distribution
The sampling distribution defines out of all the packets that match
the traffic filter, which one of those are actually used for the
measurement. One possibility is "all" which implies that all packets
matching the Traffic filter are considered, but there may be other
sampling strategies. It includes the following information:
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Value: the name of the sampling distribution
Reference definition: pointer to the specification where the
sampling distribution is properly defined.
The sampling distribution may require parameters. In case such
parameters are needed, they should be included either in the Fixed
parameter column or in the run time parameter column, depending on
whether they will be fixed or will be an input for the metric.
Sampling and Filtering Techniques for IP Packet Selection are
documented in the PSAMP (Packet Sampling) [RFC5475], while the
Framework for Packet Selection and Reporting, [RFC5474] provides more
background information. The sampling distribution parameters might
be expressed in terms of the Information Model for Packet Sampling
Exports, [RFC5477], and the Flow Selection Techniques, [RFC7014].
7.3.5. Run-time Parameters
Run-Time Parameters are Parameters that must be determined,
configured into the measurement system, and reported with the results
for the context to be complete. However, the values of these
parameters is not specified in the Performance Metrics Registry (like
the Fixed Parameters), rather these parameters are listed as an aid
to the measurement system implementer or user (they must be left as
variables, and supplied on execution).
Where metrics supply a list of Parameters as part of their
descriptive template, a sub-set of the Parameters will be designated
as Run-Time Parameters.
Parameters MUST have well defined names. For human readers, the
hanging indent style is preferred, and the names and definitions that
do not appear in the Reference Method Specification MUST appear in
this column.
A Data Format for each Run-time Parameter MUST be specified in this
column, to simplify the control and implementation of measurement
devices. For example, parameters that include an IPv4 address can be
encoded as a 32 bit integer (i.e. binary base64 encoded value) or ip-
address as defined in [RFC6991]. The actual encoding(s) used must be
explicitly defined for each Run-time parameter. IPv6 addresses and
options MUST be accommodated, allowing Registered Metrics to be used
in that address family. Other address families are permissable.
Examples of Run-time Parameters include IP addresses, measurement
point designations, start times and end times for measurement, and
other information essential to the method of measurement.
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7.3.6. Role
In some methods of measurement, there may be several roles defined,
e.g., for a one-way packet delay active measurement there is one
measurement agent that generates the packets and another agent that
receives the packets. This column contains the name of the Role(s)
for this particular entry. In the one-way delay example above, there
should be two entries in the Role registry column, one for each Role
(Source and Destination). When a measurement agent is instructed to
perform the "Source" Role for one-way delay metric, the agent knows
that it is required to generate packets. The values for this field
are defined in the reference method of measurement (and this
frequently results in abbreviated role names such as "Src").
When the Role column of a registry entry defines more than one Role,
then the Role SHALL be treated as a Run-time Parameter and supplied
for execution. It should be noted that the LMAP framework [RFC7594]
distinguishes the Role from other Run-time Parameters, and defines a
special parameter "Roles" inside the registry-grouping function list
in the LMAP YANG model[RFC8194].
7.4. Output Category
For entries which involve a stream and many singleton measurements, a
statistic may be specified in this column to summarize the results to
a single value. If the complete set of measured singletons is
output, this will be specified here.
Some metrics embed one specific statistic in the reference metric
definition, while others allow several output types or statistics.
7.4.1. Type
This column contains the name of the output type. The output type
defines a single type of result that the metric produces. It can be
the raw results (packet send times and singleton metrics), or it can
be a summary statistic. The specification of the output type MUST
define the format of the output. In some systems, format
specifications will simplify both measurement implementation and
collection/storage tasks. Note that if two different statistics are
required from a single measurement (for example, both "Xth percentile
mean" and "Raw"), then a new output type must be defined ("Xth
percentile mean AND Raw"). See the Naming section above for a list
of Output Types.
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7.4.2. Reference Definition
This column contains a pointer to the specification(s) where the
output type and format are defined.
7.4.3. Metric Units
The measured results must be expressed using some standard dimension
or units of measure. This column provides the units.
When a sample of singletons (see Section 11 of[RFC2330] for
definitions of these terms) is collected, this entry will specify the
units for each measured value.
7.4.4. Calibration
Some specifications for Methods of Measurement include the
possibility to perform an error calibration. Section 3.7.3 of
[RFC7679] is one example. In the registry entry, this field will
identify a method of calibration for the metric, and when available,
the measurement system SHOULD perform the calibration when requested
and produce the output with an indication that it is the result of a
calibration method. In-situ calibration could be enabled with an
internal loopback that includes as much of the measurement system as
possible, performs address manipulation as needed, and provides some
form of isolation (e.g., deterministic delay) to avoid send-receive
interface contention. Some portion of the random and systematic
error can be characterized this way.
For one-way delay measurements, the error calibration must include an
assessment of the internal clock synchronization with its external
reference (this internal clock is supplying timestamps for
measurement). In practice, the time offsets of clocks at both the
source and destination are needed to estimate the systematic error
due to imperfect clock synchronization (the time offsets are
smoothed, thus the random variation is not usually represented in the
results).
Both internal loopback calibration and clock synchronization can be
used to estimate the *available accuracy* of the Output Metric Units.
For example, repeated loopback delay measurements will reveal the
portion of the Output result resolution which is the result of system
noise, and thus inaccurate.
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7.5. Administrative information
7.5.1. 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.
7.5.2. Requester
The requester for the Registered Performance Metric. The requester
MAY be a document, such as RFC, or person.
7.5.3. 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.
7.5.4. Revision Date
The date of acceptance or the most recent revision for the Registered
Performance Metric. The date SHALL be determined by IANA and the
reviewing Performance Metrics Expert.
7.6. Comments and Remarks
Besides providing additional details which do not appear in other
categories, this open Category (single column) allows for unforeseen
issues to be addressed by simply updating this informational entry.
8. Processes for Managing the Performance Metric Registry Group
Once a Performance Metric or set of Performance Metrics has been
identified for a given application, candidate Performance Metrics
Registry entry specifications prepared in accordance with Section 7
should be 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 Metrics Registry, such as
deprecation or revision, as described later in this section.
It is desirable that the author(s) of a candidate Performance Metrics
Registry entry seek review in the relevant IETF working group, or
offer the opportunity for review on the working group mailing list.
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8.1. Adding new Performance Metrics to the Performance Metrics Registry
Requests to add Registered Performance Metrics in the Performance
Metrics Registry SHALL be 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
Specification Required [RFC8126] policy defined for the Performance
Metrics 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.
The most efficient path for submission begins with preparation of an
Internet Draft containing the proposed Performance Metrics Registry
entry using the template in Section 11, so that the submission
formatting will benefit from the normal IETF Internet Draft
submission processing (including HTML-ization).
Submission to IANA may be during IESG review (leading to IETF
Standards Action), where an Internet Draft proposes one or more
Registered Performance Metrics to be added to the Performance Metrics
Registry, including the text of the proposed Registered Performance
Metric(s).
If an RFC-to-be includes a Performance Metric and a proposed
Performance Metrics Registry entry, but the Performance Metric Expert
review determines that one or more of the Section 5 criteria have not
been met, then the proposed Performance Metrics Registry entry MUST
be removed from the text. Once evidence exists that the Performance
Metric meets the criteria in section 5, the proposed Performance
Metrics Registry entry SHOULD be submitted to IANA to be evaluated in
consultation with the Performance Metric Experts for registration at
that time.
Authors of proposed Registered Performance Metrics SHOULD review
compliance with the specifications in this document to check their
submissions before sending them to IANA.
At least one Performance Metric Expert should endeavor to complete
referred reviews in a timely manner. If the request is acceptable,
the Performance Metric Experts signify their approval to IANA, and
IANA updates the Performance Metrics Registry. If the request is not
acceptable, the Performance Metric Experts MAY coordinate with the
requester to change the request to be compliant, otherwise IANA SHALL
coordinate resolution of issues on behalf of the expert. The
Performance Metric Experts MAY choose to reject clearly frivolous or
inappropriate change requests outright, but such exceptional
circumstances should be rare.
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This process should not in any way be construed as allowing the
Performance Metric Experts to overrule IETF consensus. Specifically,
any Registered Performance Metrics that were added to the Performance
Metrics Registry with IETF consensus require IETF consensus for
revision or deprecation.
Decisions by the Performance Metric Experts may be appealed as in
Section 7 of [RFC8126].
8.2. Revising Registered Performance Metrics
A request for Revision is only permitted when the requested changes
maintain backward-compatibility with implementations of the prior
Performance Metrics Registry entry describing a Registered
Performance Metric (entries with lower revision numbers, but the same
Identifier and Name).
The purpose of the Status field in the Performance Metrics Registry
is to indicate whether the entry for a Registered Performance Metric
is 'current' or 'deprecated'.
In addition, no policy is defined for revising the Performance Metric
entries in the IANA Registry or addressing errors therein. To be
clear, changes and deprecations within the Performance Metrics
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 8.1, identifying the
existing Performance Metrics Registry entry, and explaining how and
why the existing entry should be revised.
The primary requirement in the definition of procedures for managing
changes to existing Registered Performance Metrics is avoidance of
measurement interoperability problems; the Performance Metric Experts
must work to maintain interoperability above all else. Changes to
Registered Performance Metrics may only be done in an interoperable
way; necessary changes that cannot be done in a way to allow
interoperability with unchanged implementations MUST result in the
creation of a new Registered Performance Metric (with a new Name,
replacing the RFCXXXXsecY portion of the name) and possibly the
deprecation of the earlier metric.
A change to a Registered Performance Metric SHALL be determined to be
backward-compatible when:
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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.
If a Performance Metric revision is deemed permissible and backward-
compatible by the Performance Metric Experts, according to the rules
in this document, IANA SHOULD execute the change(s) in the
Performance Metrics Registry. The requester of the change is
appended to the original requester in the Performance Metrics
Registry. The Name of the revised Registered Performance Metric,
including the RFCXXXXsecY portion of the name, SHALL remain unchanged
(even when the change is the result of IETF Standards Action; the
revised registry entry SHOULD reference the new immutable document,
such as an RFC or for other standards bodies, it is likely to be
necessary to reference a specific, dated version of a specification,
in an appropriate category and column).
Each Registered Performance Metric in the Performance Metrics
Registry has a revision number, starting at zero. Each change to a
Registered Performance Metric following this process increments the
revision number by one.
When a revised Registered Performance Metric is accepted into the
Performance Metrics Registry, the date of acceptance of the most
recent revision is placed into the revision Date column of the
registry for that Registered Performance Metric.
Where applicable, additions to Registered Performance Metrics in the
form of text Comments or Remarks should include the date, but such
additions may not constitute a revision according to this process.
Older version(s) of the updated metric entries are kept in the
registry for archival purposes. The older entries are kept with all
fields unmodified (version, revision date) except for the status
field that SHALL be changed to "Deprecated".
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8.3. Deprecating Registered Performance Metrics
Changes that are not permissible by the above criteria for Registered
Performance 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 8.2
Revising Registered Performance Metrics; or
2. the deprecation harmonizes with an external reference that was
itself deprecated through that reference's accepted deprecation
method.
A request for deprecation is sent to IANA, which passes it to the
Performance Metric Experts for review. When deprecating an
Performance Metric, the Performance Metric description in the
Performance Metrics 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 intentional use of deprecated Registered Performance Metrics
should result in a log entry or human-readable warning by the
respective application.
Names and Metric IDs of deprecated Registered Performance Metrics
must not be reused.
The deprecated entries are kept with all fields unmodified, except
the version, revision date, and the status field (changed to
"Deprecated").
9. Security considerations
This draft defines a registry structure, and does not itself
introduce any new security considerations for the Internet. The
definition of Performance Metrics for this registry may introduce
some security concerns, but the mandatory references should have
their own considerations for security, and such definitions should be
reviewed with security in mind if the security considerations are not
covered by one or more reference standards.
The aggregated results of the performance metrics described in this
registry might reveal network topology information that may be
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considered sensitive. If such cases are found, then access control
mechanisms should be applied.
10. IANA Considerations
With the background and processes described in earlier sections, this
document requests the following IANA Actions.
Editor's Note: Mock-ups of the implementation of this set of requests
have been prepared with IANA's help during development of this memo,
and have been captured in the Proceedings of IPPM working group
sessions. IANA is currently preparing a mock-up. A recent version
is available here: http://encrypted.net/IETFMetricsRegistry-106.html
10.1. Registry Group
The new registry group SHALL be named, "PERFORMANCE METRICS Group".
Registration Procedure: Specification Required
Reference: <This RFC>
Experts: Performance Metrics Experts
Note: TBD
10.2. Performance Metric Name Elements
This document specifies the procedure for Performance Metrics Name
Element Registry setup. IANA is requested to create a new set of
registries for Performance Metric Name Elements called "Registered
Performance Metric Name Elements". Each Registry, whose names are
listed below:
MetricType:
Method:
SubTypeMethod:
Spec:
Units:
Output:
will contain the current set of possibilities for Performance Metrics
Registry Entry Names.
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To populate the Registered Performance Metric Name Elements at
creation, the IANA is asked to use the lists of values for each name
element listed in Section 7.1.2. The Name Elements in each registry
are case-sensitive.
When preparing a Metric entry for Registration, the developer SHOULD
choose Name elements from among the registered elements. However, if
the proposed metric is unique in a significant way, it may be
necessary to propose a new Name element to properly describe the
metric, as described below.
A candidate Metric Entry RFC or immutable document for IANA and
Expert Review would propose one or more new element values required
to describe the unique entry, and the new name element(s) would be
reviewed along with the metric entry. New assignments for Registered
Performance Metric Name Elements will be administered by IANA through
Specification Required policy (which includes Expert Review)
[RFC8126], i.e., review by one of a group of experts, the Performance
Metric Experts, who are appointed by the IESG upon recommendation of
the Transport Area Directors.
10.3. New Performance Metrics Registry
This document specifies the procedure for Performance Metrics
Registry setup. IANA is requested to create a new registry for
Performance Metrics called "Performance Metrics Registry". This
Registry will contain the following Summary columns:
Identifier:
Name:
URI:
Description:
Reference:
Change Controller:
Version:
Descriptions of these columns and additional information found in the
template for registry entries (categories and columns) are further
defined in section Section 7.
The Identifier 0 should be Reserved. The Registered Performance
Metric unique identifier is an unbounded integer (range 0 to
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infinity). The Identifier values from 64512 to 65536 are reserved
for private or experimental use, and the user may encounter
overlapping uses. When adding newly Registered Performance Metrics
to the Performance Metrics Registry, IANA SHOULD assign the lowest
available identifier to the new Registered Performance Metric. If a
Performance Metrics Expert providing review determines that there is
a reason to assign a specific numeric identifier, possibly leaving a
temporary gap in the numbering, then the Performance Expert SHALL
inform IANA of this decision.
Names starting with the prefix Priv_ are reserved for private use,
and are not considered for registration. The "Name" column entries
are further defined in section Section 7.
The "URI" column will have a URL to the full template of each
registry entry. The Registry Entry text SHALL be HTML-ized to aid
the reader, with links to reference RFCs (similar to the way that
Internet Drafts are HTML-ized, the same tool can perform the
function) or immutable document.
The "Reference" column will include an RFC number, an approved
specification designator from another standards body, or other
immutable document.
New assignments for Performance Metrics Registry will be administered
by IANA through Specification Required policty (which includes Expert
Review) [RFC8126], i.e., review by one of a group of experts, the
Performance Metric Experts, who are appointed by the IESG upon
recommendation of the Transport Area Directors, or by Standards
Action. The experts can be initially drawn from the Working Group
Chairs, document editors, and members of the Performance Metrics
Directorate, among other sources of experts.
Extensions of the Performance Metrics Registry require IETF Standards
Action. Only one form of registry extension is envisaged:
1. Adding columns, or both categories and columns, to accommodate
unanticipated aspects of new measurements and metric categories.
If the Performance Metrics Registry is extended in this way, the
Version number of future entries complying with the extension SHALL
be incremented (either in the unit or tenths digit, depending on the
degree of extension.
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11. Blank Registry Template
This section provides a blank template to help IANA and registry
entry writers.
11.1. Summary
This category includes multiple indexes to the registry entry: the
element ID and metric name.
11.1.1. ID (Identifier)
<insert a numeric identifier, an integer, TBD>
11.1.2. Name
<insert name according to metric naming convention>
11.1.3. URI
URL: https://www.iana.org/ ... <name>
11.1.4. Description
<provide a description>
11.1.5. Change Controller
11.1.6. Version (of Registry Format)
11.2. Metric Definition
This category includes columns to prompt the entry of all necessary
details related to the metric definition, including the immutable
document reference and values of input factors, called fixed
parameters.
11.2.1. Reference Definition
<Full bibliographic reference to an immutable doc.>
<specific section reference and additional clarifications, if needed>
11.2.2. Fixed Parameters
<list and specify Fixed Parameters, input factors that must be
determined and embedded in the measurement system for use when
needed>
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11.3. Method of Measurement
This category includes columns for references to relevant sections of
the immutable documents(s) and any supplemental information needed to
ensure an unambiguous methods for implementations.
11.3.1. Reference Method
<for metric, insert relevant section references and supplemental
info>
11.3.2. Packet Stream Generation
<list of generation parameters and section/spec references if needed>
11.3.3. Traffic Filtering (observation) Details
The measured results based on a filtered version of the packets
observed, and this section provides the filter details (when
present).
<section reference>.
11.3.4. Sampling Distribution
<insert time distribution details, or how this is diff from the
filter>
11.3.5. Run-time Parameters and Data Format
Run-time Parameters are input factors that must be determined,
configured into the measurement system, and reported with the results
for the context to be complete.
<list of run-time parameters, and their data formats>
11.3.6. Roles
<lists the names of the different roles from the measurement method>
11.4. Output
This category specifies all details of the Output of measurements
using the metric.
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11.4.1. Type
<insert name of the output type, raw or a selected summary statistic>
11.4.2. Reference Definition
<describe the reference data format for each type of result>
11.4.3. Metric Units
<insert units for the measured results, and the reference
specification>.
11.4.4. Calibration
<insert information on calibration>
11.5. Administrative items
11.5.1. Status
<current or deprecated>
11.5.2. Requester
<name or RFC, etc.>
11.5.3. Revision
<1.0>
11.5.4. Revision Date
<format YYYY-MM-DD>
11.6. Comments and Remarks
<Additional (Informational) details for this entry>
12. Acknowledgments
Thanks to Brian Trammell and Bill Cerveny, IPPM chairs, for leading
some brainstorming sessions on this topic. Thanks to Barbara Stark
and Juergen Schoenwaelder for the detailed feedback and suggestions.
Thanks to Andrew McGregor for suggestions on metric naming. Thanks
to Michelle Cotton for her early IANA review, and to Amanda Barber
for answering questions related to the presentation of the registry
and accessibility of the complete template via URL. Thanks to Roni
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Even for his review and suggestions to generalize the procedures.
Thanks to ~all the Area Directors for their reviews.
13. References
13.1. Normative References
[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, DOI 10.17487/RFC2026, October 1996,
<https://www.rfc-editor.org/info/rfc2026>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis,
"Framework for IP Performance Metrics", RFC 2330,
DOI 10.17487/RFC2330, May 1998,
<https://www.rfc-editor.org/info/rfc2330>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New
Performance Metric Development", BCP 170, RFC 6390,
DOI 10.17487/RFC6390, October 2011,
<https://www.rfc-editor.org/info/rfc6390>.
[RFC6576] Geib, R., Ed., Morton, A., Fardid, R., and A. Steinmitz,
"IP Performance Metrics (IPPM) Standard Advancement
Testing", BCP 176, RFC 6576, DOI 10.17487/RFC6576, March
2012, <https://www.rfc-editor.org/info/rfc6576>.
[RFC7799] Morton, A., "Active and Passive Metrics and Methods (with
Hybrid Types In-Between)", RFC 7799, DOI 10.17487/RFC7799,
May 2016, <https://www.rfc-editor.org/info/rfc7799>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
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13.2. Informative References
[I-D.ietf-ippm-initial-registry]
Morton, A., Bagnulo, M., Eardley, P., and K. D'Souza,
"Initial Performance Metrics Registry Entries", draft-
ietf-ippm-initial-registry-15 (work in progress), December
2019.
[RFC2681] Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip
Delay Metric for IPPM", RFC 2681, DOI 10.17487/RFC2681,
September 1999, <https://www.rfc-editor.org/info/rfc2681>.
[RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network
performance measurement with periodic streams", RFC 3432,
DOI 10.17487/RFC3432, November 2002,
<https://www.rfc-editor.org/info/rfc3432>.
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Jacobson, "RTP: A Transport Protocol for Real-Time
Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550,
July 2003, <https://www.rfc-editor.org/info/rfc3550>.
[RFC3611] Friedman, T., Ed., Caceres, R., Ed., and A. Clark, Ed.,
"RTP Control Protocol Extended Reports (RTCP XR)",
RFC 3611, DOI 10.17487/RFC3611, November 2003,
<https://www.rfc-editor.org/info/rfc3611>.
[RFC4148] Stephan, E., "IP Performance Metrics (IPPM) Metrics
Registry", BCP 108, RFC 4148, DOI 10.17487/RFC4148, August
2005, <https://www.rfc-editor.org/info/rfc4148>.
[RFC5474] Duffield, N., Ed., Chiou, D., Claise, B., Greenberg, A.,
Grossglauser, M., and J. Rexford, "A Framework for Packet
Selection and Reporting", RFC 5474, DOI 10.17487/RFC5474,
March 2009, <https://www.rfc-editor.org/info/rfc5474>.
[RFC5475] Zseby, T., Molina, M., Duffield, N., Niccolini, S., and F.
Raspall, "Sampling and Filtering Techniques for IP Packet
Selection", RFC 5475, DOI 10.17487/RFC5475, March 2009,
<https://www.rfc-editor.org/info/rfc5475>.
[RFC5477] Dietz, T., Claise, B., Aitken, P., Dressler, F., and G.
Carle, "Information Model for Packet Sampling Exports",
RFC 5477, DOI 10.17487/RFC5477, March 2009,
<https://www.rfc-editor.org/info/rfc5477>.
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[RFC6035] Pendleton, A., Clark, A., Johnston, A., and H. Sinnreich,
"Session Initiation Protocol Event Package for Voice
Quality Reporting", RFC 6035, DOI 10.17487/RFC6035,
November 2010, <https://www.rfc-editor.org/info/rfc6035>.
[RFC6248] Morton, A., "RFC 4148 and the IP Performance Metrics
(IPPM) Registry of Metrics Are Obsolete", RFC 6248,
DOI 10.17487/RFC6248, April 2011,
<https://www.rfc-editor.org/info/rfc6248>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model
for IP Flow Information Export (IPFIX)", RFC 7012,
DOI 10.17487/RFC7012, September 2013,
<https://www.rfc-editor.org/info/rfc7012>.
[RFC7014] D'Antonio, S., Zseby, T., Henke, C., and L. Peluso, "Flow
Selection Techniques", RFC 7014, DOI 10.17487/RFC7014,
September 2013, <https://www.rfc-editor.org/info/rfc7014>.
[RFC7594] Eardley, P., Morton, A., Bagnulo, M., Burbridge, T.,
Aitken, P., and A. Akhter, "A Framework for Large-Scale
Measurement of Broadband Performance (LMAP)", RFC 7594,
DOI 10.17487/RFC7594, September 2015,
<https://www.rfc-editor.org/info/rfc7594>.
[RFC7679] Almes, G., Kalidindi, S., Zekauskas, M., and A. Morton,
Ed., "A One-Way Delay Metric for IP Performance Metrics
(IPPM)", STD 81, RFC 7679, DOI 10.17487/RFC7679, January
2016, <https://www.rfc-editor.org/info/rfc7679>.
[RFC8194] Schoenwaelder, J. and V. Bajpai, "A YANG Data Model for
LMAP Measurement Agents", RFC 8194, DOI 10.17487/RFC8194,
August 2017, <https://www.rfc-editor.org/info/rfc8194>.
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
BT
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
Aamer Akhter
Consultant
118 Timber Hitch
Cary, NC
USA
Email: aakhter@gmail.com
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