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Versions: (draft-mornuley-ippm-registry-active) 00 01 draft-ietf-ippm-metric-registry

Network Working Group                                          A. Morton
Internet-Draft                                                 AT&T Labs
Intended status: Standards Track                              M. Bagnulo
Expires: January 5, 2015                                            UC3M
                                                              P. Eardley
                                                                      BT
                                                            July 4, 2014


                 Active Performance Metric Sub-Registry
                   draft-ietf-ippm-registry-active-01

Abstract

   This memo defines the Active Performance Metrics sub-registry of the
   Performance Metric Registry.  This sub-registry will contain Active
   Performance Metrics, especially those defined in RFCs prepared in the
   IP Performance Metrics (IPPM) Working Group of the IETF, and possibly
   applicable to other IETF metrics.  Three aspects make IPPM metric
   registration difficult: (1) Use of the Type-P notion to allow users
   to specify their own packet types. (2) Use of flexible input
   variables, called Parameters in IPPM definitions, some of which
   determine the quantity measured and others of which should not be
   specified until execution of the measurement. (3) Allowing
   flexibility in choice of statistics to summarize the results on a
   stream of measurement packets.

   This memo proposes a way to organize registry entries into columns
   that are well-defined, permitting consistent development of entries
   over time (a column may marked NA if it is not applicable for that
   metric).  The design is intended to foster development of registry
   entries based on existing reference RFCs, whilst each column serves
   as a check-list item to avoid omissions during the registration
   process.  Every entry in the registry, before IANA action, requires
   Expert review as defined by concurrent IETF work in progress
   "Registry for Performance Metrics" (draft-ietf-ippm-metric-registry).

   The document contains two examples: a registry entry for an active
   Performance Metric entry based on RFC3393 and RFC5481, and a registry
   entry for an end-point Performance Metric based on RFC 7003.  The
   examples are for Informational purposes and do not create any entry
   in the IANA registry.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].



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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
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   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire on January 5, 2015.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Background and Motivation . . . . . . . . . . . . . . . .   5
   2.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
   3.  Registry Categories and Columns . . . . . . . . . . . . . . .   8
     3.1.  Common Registry Indexes and Information . . . . . . . . .   8
       3.1.1.  Identifier  . . . . . . . . . . . . . . . . . . . . .   8
       3.1.2.  Name  . . . . . . . . . . . . . . . . . . . . . . . .   9
       3.1.3.  URI . . . . . . . . . . . . . . . . . . . . . . . . .   9
       3.1.4.  Status  . . . . . . . . . . . . . . . . . . . . . . .   9
       3.1.5.  Requester . . . . . . . . . . . . . . . . . . . . . .   9
       3.1.6.  Revision  . . . . . . . . . . . . . . . . . . . . . .   9
       3.1.7.  Revision Date . . . . . . . . . . . . . . . . . . . .   9
       3.1.8.  Description . . . . . . . . . . . . . . . . . . . . .   9
       3.1.9.  Reference Specification(s)  . . . . . . . . . . . . .   9



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     3.2.  Metric Definition . . . . . . . . . . . . . . . . . . . .   9
       3.2.1.  Reference Definition  . . . . . . . . . . . . . . . .   9
       3.2.2.  Fixed Parameters  . . . . . . . . . . . . . . . . . .  10
     3.3.  Method of Measurement . . . . . . . . . . . . . . . . . .  10
       3.3.1.  Reference Method  . . . . . . . . . . . . . . . . . .  10
       3.3.2.  Stream Type and Stream Parameters . . . . . . . . . .  10
       3.3.3.  Output Type and Data Format . . . . . . . . . . . . .  11
       3.3.4.  Metric Units  . . . . . . . . . . . . . . . . . . . .  11
       3.3.5.  Run-time Parameters and Data Format . . . . . . . . .  12
     3.4.  Comments and Remarks  . . . . . . . . . . . . . . . . . .  12
   4.  Example IPPM Active Registry Entry  . . . . . . . . . . . . .  12
     4.1.  Registry Indexes  . . . . . . . . . . . . . . . . . . . .  12
       4.1.1.  Identifier  . . . . . . . . . . . . . . . . . . . . .  12
       4.1.2.  Name  . . . . . . . . . . . . . . . . . . . . . . . .  13
       4.1.3.  URI . . . . . . . . . . . . . . . . . . . . . . . . .  13
       4.1.4.  Status  . . . . . . . . . . . . . . . . . . . . . . .  13
       4.1.5.  Requestor . . . . . . . . . . . . . . . . . . . . . .  13
       4.1.6.  Revision  . . . . . . . . . . . . . . . . . . . . . .  13
       4.1.7.  Revision Date . . . . . . . . . . . . . . . . . . . .  13
       4.1.8.  Description . . . . . . . . . . . . . . . . . . . . .  13
       4.1.9.  Reference Specification(s)  . . . . . . . . . . . . .  13
     4.2.  Metric Definition . . . . . . . . . . . . . . . . . . . .  13
       4.2.1.  Reference Definition  . . . . . . . . . . . . . . . .  13
       4.2.2.  Fixed Parameters  . . . . . . . . . . . . . . . . . .  14
     4.3.  Method of Measurement . . . . . . . . . . . . . . . . . .  14
       4.3.1.  Reference Method  . . . . . . . . . . . . . . . . . .  14
       4.3.2.  Stream Type and Stream Parameters . . . . . . . . . .  14
       4.3.3.  Output Type and Data Format . . . . . . . . . . . . .  14
       4.3.4.  Metric Units  . . . . . . . . . . . . . . . . . . . .  15
       4.3.5.  Run-time Parameters and Data Format . . . . . . . . .  15
     4.4.  Comments and Remarks  . . . . . . . . . . . . . . . . . .  16
   5.  Example RTCP-XR Registry Entry  . . . . . . . . . . . . . . .  16
     5.1.  Registry Indexes  . . . . . . . . . . . . . . . . . . . .  16
       5.1.1.  Identifier  . . . . . . . . . . . . . . . . . . . . .  16
       5.1.2.  Name  . . . . . . . . . . . . . . . . . . . . . . . .  16
       5.1.3.  URI . . . . . . . . . . . . . . . . . . . . . . . . .  16
       5.1.4.  Status  . . . . . . . . . . . . . . . . . . . . . . .  17
       5.1.5.  Requestor . . . . . . . . . . . . . . . . . . . . . .  17
       5.1.6.  Revision  . . . . . . . . . . . . . . . . . . . . . .  17
       5.1.7.  Revision Date . . . . . . . . . . . . . . . . . . . .  17
       5.1.8.  Description . . . . . . . . . . . . . . . . . . . . .  17
       5.1.9.  Reference Specification(s)  . . . . . . . . . . . . .  17
     5.2.  Metric Definition . . . . . . . . . . . . . . . . . . . .  17
       5.2.1.  Reference Definition  . . . . . . . . . . . . . . . .  17
       5.2.2.  Fixed Parameters  . . . . . . . . . . . . . . . . . .  17
     5.3.  Method of Measurement . . . . . . . . . . . . . . . . . .  18
       5.3.1.  Reference Method  . . . . . . . . . . . . . . . . . .  18
       5.3.2.  Stream Type and Stream Parameters . . . . . . . . . .  19



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       5.3.3.  Output Type and Data Format . . . . . . . . . . . . .  19
       5.3.4.  Metric Units  . . . . . . . . . . . . . . . . . . . .  19
       5.3.5.  Run-time Parameters and Data Format . . . . . . . . .  19
     5.4.  Comments and Remarks  . . . . . . . . . . . . . . . . . .  21
   6.  Example BLANK Registry Entry  . . . . . . . . . . . . . . . .  21
     6.1.  Registry Indexes  . . . . . . . . . . . . . . . . . . . .  21
       6.1.1.  Identifier  . . . . . . . . . . . . . . . . . . . . .  21
       6.1.2.  Name  . . . . . . . . . . . . . . . . . . . . . . . .  21
       6.1.3.  URI . . . . . . . . . . . . . . . . . . . . . . . . .  21
       6.1.4.  Status  . . . . . . . . . . . . . . . . . . . . . . .  21
       6.1.5.  Requestor . . . . . . . . . . . . . . . . . . . . . .  21
       6.1.6.  Revision  . . . . . . . . . . . . . . . . . . . . . .  21
       6.1.7.  Revision Date . . . . . . . . . . . . . . . . . . . .  22
       6.1.8.  Description . . . . . . . . . . . . . . . . . . . . .  22
       6.1.9.  Reference Specification(s)  . . . . . . . . . . . . .  22
     6.2.  Metric Definition . . . . . . . . . . . . . . . . . . . .  22
       6.2.1.  Reference Definition  . . . . . . . . . . . . . . . .  22
       6.2.2.  Fixed Parameters  . . . . . . . . . . . . . . . . . .  22
     6.3.  Method of Measurement . . . . . . . . . . . . . . . . . .  22
       6.3.1.  Reference Method  . . . . . . . . . . . . . . . . . .  22
       6.3.2.  Stream Type and Stream Parameters . . . . . . . . . .  22
       6.3.3.  Output Type and Data Format . . . . . . . . . . . . .  23
       6.3.4.  Metric Units  . . . . . . . . . . . . . . . . . . . .  23
       6.3.5.  Run-time Parameters and Data Format . . . . . . . . .  23
     6.4.  Comments and Remarks  . . . . . . . . . . . . . . . . . .  23
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  23
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  23
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  24
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  24
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  25
     10.2.  Informative References . . . . . . . . . . . . . . . . .  25
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   [ISSUES

   1.  REAL-TIME OR INPUT PARAMETER [CONSISTENT WITH REGISTRY I-D]
   closed - just Parameter

   2.  CHANGED STREAM PARAMETER TO STREAM INPUT PARAMETER I didn't find
   any instances of this change - closed

   3.  I PREFER KEEPING THE CATEGORY-COLUMN HIERARCHY - ok we keep it

   4.  RATHER THAN BLANK COLUMNS, SHOULD WE HAVE 'NOT APPLICABLE' [MAYBE
   EVEN IANA REGISTERED??] sounds good to Al, used NA.




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   5.  THE EXAMPLES ARE INFORMATIONAL NOT STANDARDS TRACK yes of course
   - -Closed.

   -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

   Note: Efforts to synchronize terminology with
   [I-D.ietf-ippm-metric-registry] will likely be incomplete until both
   drafts are stable.

   This memo defines the Active Performance Metrics sub-registry of the
   Performance Metric Registry.  This sub-registry will contain Active
   Performance Metrics, especially those defined in RFCs prepared in the
   IP Performance Metrics (IPPM) Working Group of the IETF, according to
   their framework [RFC2330].  Three aspects make IPPM metric
   registration difficult: (1) Use of the Type-P notion to allow users
   to specify their own packet types. (2) Use of Flexible input
   variables, called Parameters in IPPM definitions, some which
   determine the quantity measured and others which should not be
   specified until execution of the measurement. (3) Allowing
   flexibility in choice of statistics to summarize the results on a
   stream of measurement packets.  This memo uses terms and definitions
   from the IPPM literature, primarily [RFC2330], and the reader is
   assumed familiar with them or may refer questions there as necessary.

   This sub-registry is part of the Performance Metric Registry
   [I-D.ietf-ippm-metric-registry] which specifies that all sub-
   registries must contain at least the following fields: the
   identifier, the name, the status, the requester, the revision, the
   revision date, the description for each entry, and the reference
   specifications used as the foundation for the Registered Performance
   Metric (see [I-D.ietf-ippm-metric-registry]).

   Although there are several standard templates for organizing
   specifications of performance metrics (see [RFC2679] for an example
   of the traditional IPPM template, based to large extent on the
   Benchmarking Methodology Working Group's traditional template in
   [RFC1242], and see [RFC6390] for a similar template), none of these
   templates was intended to become the basis for the columns of an
   IETF-wide registry of metrics.  As we examined the aspects of metric
   specifications which need to be registered, it was clear that none of
   the existing metric templates fully satisfies the particular needs of
   a registry.

1.1.  Background and Motivation

   One clear motivation for having such a registry is to allow a
   controller to request a measurement agent to execute a measurement
   using a specific metric (see [I-D.ietf-lmap-framework]).  Such a



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   request can be performed using any control protocol that refers to
   the value assigned to the specific metric in the registry.
   Similarly, the measurement agent can report the results of the
   measurement and by referring to the metric value it can unequivocally
   identify the metric that the results correspond to.

   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".

   Our 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.
   Each may require run-time parameters to set factors like source and
   destination addresses, which do not change the fundamental nature of
   the measurement and can be set just before measurement execution.
   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 it is required for all registries within the Performance
   Metric Registry (see [I-D.ietf-ippm-metric-registry]) that the
   registry only includes commonly used metrics that are well defined;
   hence we require expert review policies for the approval and
   assignment of entries in this sub-registry.

   There are several side benefits of having a registry with well-chosen
   entries.  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 and method
   is unambiguously defined.

   The registry constitutes a key component of a 'Characterization
   Plan'.  It describes various factors that need to be set by the party
   controlling the measurements, for example: specific values for the
   parameters associated with the selected registry entry (for instance,
   source and destination addresses); and how often the measurement is
   made.  The Characterization Plan determines the individual
   Measurement Tasks which Measurement Agents will be instructed to do
   and which they then execute autonomously.

   Measurement Instructions might look something like: "Dear measurement
   agent: Please start test DNS(example.com) and RTT(server.com,150)



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   every day at 2000 GMT.  Run the DNS test 5 times and the RTT test 50
   times.  Do that when the network is idle.  Generate both raw results
   and 99th percentile mean.  Send measurement results to collector.com
   in IPFIX format".  The Characterization Plan depends on the
   requirements of the controlling party.  For instance the broadband
   consumer might want a one-off measurement made immediately to one
   specific server; a regulator might want the same measurement made
   once a day until further notice to the 'top 10' servers; whilst an
   operator might want a varying series of tests (some of which will be
   beyond those defined in an IETF registry) as determined from time to
   time by their operational support system.  While the registries
   defined in this document help to define the Characterization Plan,
   its full specification falls outside the scope of this document, and
   other IETF work as currently chartered.

   Note: Some operators of performance management systems will have the
   capability to stop measurement activity on demand, and may benefit
   from knowledge of recommended default behavior for the Metrics in the
   active sub-registry.  Since active methods of performance measurement
   generate dedicated traffic, the default behavior should be to stop
   measurement activity when requested by the management protocol.

2.  Scope

   [I-D.ietf-ippm-metric-registry] defines the overall structure for a
   Performance Metric Registry and provides guidance for defining a sub
   registry.

   This document defines the Active Performance Metrics Sub-registry;
   active metrics are those where the packets measured have been
   specially generated for the purpose.

   A row in the registry corresponds to one Registered Performance
   Metric, with entries in the various columns specifying the metric.
   Section 3 defines the columns for a Registered Active Performance
   Metric.

   As discussed in [I-D.ietf-ippm-metric-registry], each entry (row)
   must be tightly defined; the definition must leave open only a few
   parameters that do not change the fundamental nature of the
   measurement (such as source and destination addresses), and so
   promotes comparable results across independent implementations.
   Also, each registered entry must be based on existing reference RFCs
   (or other standards) for performance metrics, and must be
   operationally useful and have significant industry interest.  This is
   ensured by expert review for every entry before IANA action.





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3.  Registry Categories and Columns

   This section defines the categories and columns of the registry.
   Below, categories are described at the 3.x heading level, and columns
   are at the 3.x.y heading level.  The Figure below illustrates this
   organization.  An entry (row) therefore gives a complete description
   of a Registered Metric.

   Each column serves as a check-list item and helps to avoid omissions
   during registration and expert review.  In some cases an entry (row)
   may have some columns without specific entries, marked Not Applicable
   (NA).

    Registry Categories and Columns, shown as
                                                   Category
                                                   ------------------
                                                   Column |  Column |
   Common Registry Indexes and Information
   ---------------------------------------------------------------------
   ID | Name | Status |Request | Rev| Rev.Date | Description | Ref Spec|


   Metric Definition
   -----------------------------------------
   Reference Definition | Fixed Parameters |


   Method of Measurement
   ----------------------------------------------------------------
   Reference Method | Stream Type    | Output | Output | Run-time |
                    | and Parameters | Type   | Units  | Param

   Comments and Remarks
   --------------------



3.1.  Common Registry Indexes and Information

   This category has multiple indexes to each registry entry.  It is
   defined in [I-D.ietf-ippm-metric-registry]:

3.1.1.  Identifier

   Defined in [I-D.ietf-ippm-metric-registry].  In order to have the
   document self contained, we could copy the definition from
   [I-D.ietf-ippm-metric-registry] here, but i guess we should do that
   once the definition in [I-D.ietf-ippm-metric-registry] is stable.



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3.1.2.  Name

   Defined in [I-D.ietf-ippm-metric-registry], same comment than above.

3.1.3.  URI

   Defined in [I-D.ietf-ippm-metric-registry], same comment than above.

3.1.4.  Status

   Defined in [I-D.ietf-ippm-metric-registry], same comment than above.

3.1.5.  Requester

   Defined in [I-D.ietf-ippm-metric-registry], same comment than above.

3.1.6.  Revision

   Defined in [I-D.ietf-ippm-metric-registry], same comment than above.

3.1.7.  Revision Date

   Defined in [I-D.ietf-ippm-metric-registry], same comment than above.

3.1.8.  Description

   Defined in [I-D.ietf-ippm-metric-registry], same comment as the
   previous.

3.1.9.  Reference Specification(s)

   Defined in [I-D.ietf-ippm-metric-registry], same comment as the
   previous.

3.2.  Metric Definition

   This category includes columns to prompt all necessary details
   related to the metric definition, including the RFC reference and
   values of input factors, called fixed parameters, which are left open
   in the RFC but have a particular value defined by the performance
   metric.

3.2.1.  Reference Definition

   This entry provides references to relevant sections of the RFC(s)
   defining the metric, as well as any supplemental information needed
   to ensure an unambiguous definition for implementations.




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3.2.2.  Fixed Parameters

   Fixed Parameters are input factors whose value must be specified in
   the 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.  For example, 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.

   A Parameter which is Fixed for one Registry entry may be designated
   as a Run-time Parameter for another Registry entry.

3.3.  Method of Measurement

   This category includes columns for references to relevant sections of
   the RFC(s) and any supplemental information needed to ensure an
   unambiguous method for implementations.

3.3.1.  Reference Method

   This entry provides references to relevant sections of the RFC(s)
   describing the method of measurement, as well as any supplemental
   information needed to ensure unambiguous interpretation for
   implementations referring to the RFC text.

3.3.2.  Stream Type and Stream Parameters

   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 values is specified in this
   column.

   Each entry for this column contains the following information:

   o  Value: The name of the packet stream scheduling discipline

   o  Stream Parameters: The values and formats of input factors for
      each type of stream.  For example, the average packet rate and
      distribution truncation value for streams with Poisson-distributed
      inter-packet sending times.

   o  Reference: the specification where the stream is defined

   The simplest example of stream specification is Singleton scheduling,
   where a single atomic measurement is conducted.  Each atomic



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   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.

3.3.3.  Output Type and Data Format

   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.

   Each entry in the output type column contains the following
   information:

   o  Value: The name of the output type

   o  Data Format: provided to simplify the communication with
      collection systems and implementation of measurement devices.

   o  Reference: the specification where the output type is defined

   The output type defines the type of result that the metric produces.
   It can be the raw results or it can be some form of 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").

3.3.4.  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 [RFC2330] for definitions of these
   terms) is collected, this entry will specify the units for each
   measured value.








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3.3.5.  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.  However, the values of these
   parameters is not specified in the Registry, rather these parameters
   are listed as an aid to the measurement system implementor 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.

   The Data Format of each Run-time Parameter SHALL be specified in this
   column, to simplify the control and implementation of measurement
   devices.

   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.

3.4.  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.

4.  Example IPPM Active Registry Entry

   This section is Informational.

   This section gives an example registry entry for the active metric
   described in [RFC3393], on Packet Delay Variation.

4.1.  Registry Indexes

   This category includes multiple indexes to the registry entries, the
   element ID and metric name.

4.1.1.  Identifier

   An integer having enough digits to uniquely identify each entry in
   the Registry.








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4.1.2.  Name

   A metric naming convention is TBD.

   One possibility based on IPPM's framework is:

   Act_IP-UDP-One-way-pdv-95th-percentile-Poisson

4.1.3.  URI

   Prefix urn:ietf:params:performance:metric

4.1.4.  Status

   current

4.1.5.  Requestor

   Alcelip Mornuley

4.1.6.  Revision

   1.0

4.1.7.  Revision Date

   2014-07-04

4.1.8.  Description

   An assessment of packet delay variation with respect to the minimum
   delay observed on the stream.

4.1.9.  Reference Specification(s)

   [RFC2330][RFC3393][RFC5481][RFC5905]

4.2.  Metric Definition

   This category includes columns to prompt the entry of all necessary
   details related to the metric definition, including the RFC reference
   and values of input factors, called fixed parameters.

4.2.1.  Reference Definition

   See sections 2.4 and 3.4 of [RFC3393].  Singleton delay differences
   measured are referred to by the variable name "ddT".




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4.2.2.  Fixed Parameters

   Since the metric's reference supplies a list of Parameters as part of
   its descriptive template, a sub-set of the Parameters have been
   designated as designated as Fixed Parameters for this entry.

   o  F, a selection function defining unambiguously the packets from
      the stream selected for the metric.  See section 4.2 of [RFC5481]
      for the PDV form.

   o  L, a packet length in bits.  L = 200 bits.

   o  Tmax, a maximum waiting time for packets to arrive at Dst, set
      sufficiently long to disambiguate packets with long delays from
      packets that are discarded (lost).  Tmax = 3 seconds.

   o  Type-P, as defined in [RFC2330], which includes any field that may
      affect a packet's treatment as it traverses the network.  The
      packets are IP/UDP, with DSCP = 0 (BE).

4.3.  Method of Measurement

   This category includes columns for references to relevant sections of
   the RFC(s) and any supplemental information needed to ensure an
   unambiguous methods for implementations.

4.3.1.  Reference Method

   See section 2.6 and 3.6 of [RFC3393] for singleton elements.

4.3.2.  Stream Type and Stream Parameters

   Poisson distributed as described in [RFC2330], with the following
   Parameters.

   o  lambda, a rate in reciprocal seconds (for Poisson Streams).
      lambda = 1 packet per second

   o  Upper limit on Poisson distribution (values above this limit will
      be clipped and set to the limit value).  Upper limit = 30 seconds.

4.3.3.  Output Type and Data Format

   See section 4.3 of [RFC3393] for details on the percentile statistic.

   The percentile = 95.

   Data format is a 32-bit unsigned floating point value.



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   Individual results (singletons) should be represented by the
   following triple

   o  T1 and T2, times as described below in the Run-time parameters
      section.

   o  ddT as defined in section 2.4 of [RFC3393]

   if needed.  The result format for ddT is *similar to* the short
   format in [RFC5905] (32 bits) and is as follows: the first 16 bits
   represent the *signed* integer number of seconds; the next 16 bits
   represent the fractional part of a second.

4.3.4.  Metric Units

   See section 3.3 of [RFC3393] for singleton elements.

   [RFC2330] recommends that when a time is given, it will be expressed
   in UTC.

   The timestamp format (for T, Tf, etc.) is the same as in [RFC5905]
   (64 bits) and is as follows: the first 32 bits represent the unsigned
   integer number of seconds elapsed since 0h on 1 January 1900; the
   next 32 bits represent the fractional part of a second that has
   elapsed since then.

4.3.5.  Run-time Parameters and Data Format

   Since the metric's reference supplies a list of Parameters as part of
   its descriptive template, a sub-set of the Parameters have been
   designated as Run-Time Parameters for this entry.  In related
   registry entries, some of the parameters below may be designated as
   Fixed Parameters instead.

   o  Src, the IP address of a host (32-bit value for IPv4, 128-bit
      value for IPv6)

   o  Dst, the IP address of a host (32-bit value for IPv4, 128-bit
      value for IPv6)

   o  T, a time (start of test interval, 128-bit NTP Date Format, see
      section 6 of [RFC5905])

   o  Tf, a time (end of test interval, 128-bit NTP Date Format, see
      section 6 of [RFC5905])






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   o  T1, the wire time of the first packet in a pair, measured at
      MP(Src) as it leaves for Dst (64-bit NTP Timestamp Format, see
      section 6 of [RFC5905]).

   o  T2, the wire time of the second packet in a pair, measured at
      MP(Src) as it leaves for Dst (64-bit NTP Timestamp Format, see
      section 6 of [RFC5905]).

   o  I(i),I(i+1), i >=0, pairs of times which mark the beginning and
      ending of the intervals in which the packet stream from which the
      measurement is taken occurs.  Here, I(0) = T0 and assuming that n
      is the largest index, I(n) = Tf (pairs of 64-bit NTP Timestamp
      Format, see section 6 of [RFC5905]).

4.4.  Comments and Remarks

   Lost packets represent a challenge for delay variation metrics.  See
   section 4.1 of [RFC3393] and the delay variation applicability
   statement[RFC5481] for extensive analysis and comparison of PDV and
   an alternate metric, IPDV.

5.  Example RTCP-XR Registry Entry

   This section is Informational.

   This section gives an example registry entry for the end-point metric
   described in RFC 7003 [RFC7003], for RTCP-XR Burst/Gap Discard Metric
   reporting.

5.1.  Registry Indexes

   This category includes multiple indexes to the registry entries, the
   element ID and metric name.

5.1.1.  Identifier

   An integer having enough digits to uniquely identify each entry in
   the Registry.

5.1.2.  Name

   A metric naming convention is TBD.

5.1.3.  URI

   Prefix urn:ietf:params:performance:metric





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5.1.4.  Status

   current

5.1.5.  Requestor

   Alcelip Mornuley

5.1.6.  Revision

   1.0

5.1.7.  Revision Date

   2014-07-04

5.1.8.  Description

   TBD.

5.1.9.  Reference Specification(s)

   [RFC3611][RFC4566][RFC6776][RFC6792][RFC7003]

5.2.  Metric Definition

   This category includes columns to prompt the entry of all necessary
   details related to the metric definition, including the RFC reference
   and values of input factors, called fixed parameters.  Section 3.2 of
   [RFC7003] provides the reference information for this category.

5.2.1.  Reference Definition

   Packets Discarded in Bursts:

   The total number of packets discarded during discard bursts.  The
   measured value is unsigned value.  If the measured value exceeds
   0xFFFFFD, the value 0xFFFFFE MUST be reported to indicate an over-
   range measurement.  If the measurement is unavailable, the value
   0xFFFFFF MUST be reported.

5.2.2.  Fixed Parameters

   Fixed Parameters are input factors that must be determined and
   embedded in the measurement system for use when needed.  The values
   of these parameters is specified in the Registry.

   Threshold: 8 bits, set to value = 3 packets.



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   The Threshold is equivalent to Gmin in [RFC3611], i.e., the number of
   successive packets that must not be discarded prior to and following
   a discard packet in order for this discarded packet to be regarded as
   part of a gap.  Note that the Threshold is set in accordance with the
   Gmin calculation defined in Section 4.7.2 of [RFC3611].

   Interval Metric flag: 2 bits, set to value 11=Cumulative Duration

   This field is used to indicate whether the burst/gap discard metrics
   are Sampled, Interval, or Cumulative metrics [RFC6792]:

   I=10: Interval Duration - the reported value applies to the most
   recent measurement interval duration between successive metrics
   reports.

   I=11: Cumulative Duration - the reported value applies to the
   accumulation period characteristic of cumulative measurements.

   Senders MUST NOT use the values I=00 or I=01.

5.3.  Method of Measurement

   This category includes columns for references to relevant sections of
   the RFC(s) and any supplemental information needed to ensure an
   unambiguous methods for implementations.  For the Burst/Gap Discard
   Metric, it appears that the only guidance on methods of measurement
   is in Section 3.0 of [RFC7003] and its supporting references.
   Relevant information is repeated below, although there appears to be
   no section titled "Method of Measurement" in [RFC7003].

5.3.1.  Reference Method

   Metrics in this block report on burst/gap discard in the stream
   arriving at the RTP system.  Measurements of these metrics are made
   at the receiving end of the RTP stream.  Instances of this metrics
   block use the synchronization source (SSRC) to refer to the separate
   auxiliary Measurement Information Block [RFC6776], which describes
   measurement periods in use (see [RFC6776], Section 4.2).

   This metrics block relies on the measurement period in the
   Measurement Information Block indicating the span of the report.
   Senders MUST send this block in the same compound RTCP packet as the
   Measurement Information Block.  Receivers MUST verify that the
   measurement period is received in the same compound RTCP packet as
   this metrics block.  If not, this metrics block MUST be discarded.






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5.3.2.  Stream Type and Stream Parameters

   Since RTCP-XR Measurements are conducted on live RTP traffic, the
   complete description of the stream is contained in SDP messages that
   proceed the establishment of a compatible stream between two or more
   communicating hosts.  See Run-time Parameters, below.

5.3.3.  Output Type and Data Format

   The output type defines the type of result that the metric produces.

   o  Value: Packets Discarded in Bursts

   o  Data Format: 24 bits

   o  Reference: Section 3.2 of [RFC7003]

5.3.4.  Metric Units

   The measured results are apparently expressed in packets, although
   there is no section of [RFC7003] titled "Metric Units".

5.3.5.  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.  However, the values of these
   parameters is not specified in the Registry, rather these parameters
   are listed as an aid to the measurement system implementor or user
   (they must be left as variables, and supplied on execution).

   The Data Format of each Run-time Parameter SHALL be specified in this
   column, to simplify the control and implementation of measurement
   devices.

   SSRC of Source: 32 bits As defined in Section 4.1 of [RFC3611].

   SDP Parameters: As defined in [RFC4566]

   Session description v= (protocol version number, currently only 0)

   o= (originator and session identifier : username, id, version number,
   network address)

   s= (session name : mandatory with at least one UTF-8-encoded
   character)

   i=* (session title or short information) u=* (URI of description)



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   e=* (zero or more email address with optional name of contacts)

   p=* (zero or more phone number with optional name of contacts)

   c=* (connection information--not required if included in all media)

   b=* (zero or more bandwidth information lines) One or more Time
   descriptions ("t=" and "r=" lines; see below)

   z=* (time zone adjustments)

   k=* (encryption key)

   a=* (zero or more session attribute lines)

   Zero or more Media descriptions (each one starting by an "m=" line;
   see below)

   m= (media name and transport address)

   i=* (media title or information field)

   c=* (connection information -- optional if included at session level)

   b=* (zero or more bandwidth information lines)

   k=* (encryption key)

   a=* (zero or more media attribute lines -- overriding the Session
   attribute lines)

   An example Run-time SDP description follows:

   v=0

   o=jdoe 2890844526 2890842807 IN IP4 192.0.2.5

   s=SDP Seminar i=A Seminar on the session description protocol

   u=http://www.example.com/seminars/sdp.pdf e=j.doe@example.com (Jane
   Doe)

   c=IN IP4 233.252.0.12/127

   t=2873397496 2873404696

   a=recvonly




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   m=audio 49170 RTP/AVP 0

   m=video 51372 RTP/AVP 99

   a=rtpmap:99 h263-1998/90000

5.4.  Comments and Remarks

   TBD.

6.  Example BLANK Registry Entry

   This section is Informational. (?)

   This section gives an example registry entry for the <type of metric
   and specification reference> .

6.1.  Registry Indexes

   This category includes multiple indexes to the registry entries, the
   element ID and metric name.

6.1.1.  Identifier

   An integer.

6.1.2.  Name

   A metric naming convention is TBD.

6.1.3.  URI

   Prefix urn:ietf:params:performance:metric

6.1.4.  Status

   current

6.1.5.  Requestor

   name or RFC, etc.

6.1.6.  Revision

   1.0






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6.1.7.  Revision Date

   YYYY-MM-DD

6.1.8.  Description

   TBD.

6.1.9.  Reference Specification(s)

   RFC...

6.2.  Metric Definition

   This category includes columns to prompt the entry of all necessary
   details related to the metric definition, including the RFC reference
   and values of input factors, called fixed parameters.

   <possible section reference>.

6.2.1.  Reference Definition

6.2.2.  Fixed Parameters

   Fixed Parameters are input factors that must be determined and
   embedded in the measurement system for use when needed.  The values
   of these parameters is specified in the Registry.

   <list fixed parameters>

6.3.  Method of Measurement

   This category includes columns for references to relevant sections of
   the RFC(s) and any supplemental information needed to ensure an
   unambiguous methods for implementations.

6.3.1.  Reference Method

   For <metric>.

   <section reference>

6.3.2.  Stream Type and Stream Parameters

   <list of stream parameters>.

   <references>




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6.3.3.  Output Type and Data Format

   The output type defines the type of result that the metric produces.

   o  Value:

   o  Data Format: (There may be some precedent to follow here, but
      otherwise use 64-bit NTP Timestamp Format, see section 6 of
      [RFC5905]).

   o  Reference: <section reference>

6.3.4.  Metric Units

   The measured results are expressed in <units>,

   <section reference>.

6.3.5.  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>

   <reference(s)>.

6.4.  Comments and Remarks

   Additional (Informational) details for this entry

7.  Security Considerations

   This registry has no known implications on Internet Security.

8.  IANA Considerations

   IANA is requested to create The Active Performance Metric Sub-
   registry within the Performance Metric Registry defined in
   [I-D.ietf-ippm-metric-registry].  The Sub-registry will contain the
   following categories and (bullet) columns, (as defined in section 3
   above):

   Common Registry Indexes and Info

   o  Identifier




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   o  Name

   o  Status

   o  Requester

   o  Revision

   o  Revision Date

   o  Description

   o  Reference Specification(s)

   Metric Definition

   o  Reference Definition

   o  Fixed Parameters

   Method of Measurement

   o  Reference Method

   o  Stream Type and Parameters

   o  Output type and Data format

   o  Metric Units

   o  Run-time Parameters

   Comments and Remarks

9.  Acknowledgements

   The authors thank Brian Trammell for suggesting the term "Run-time
   Parameters", which led to the distinction between run-time and fixed
   parameters implemented in this memo, for raising the IPFIX metric
   with Flow Key as an example, and for many other productive
   suggestions.

10.  References








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10.1.  Normative References

   [I-D.ietf-ippm-metric-registry]
              Bagnulo, M., Claise, B., Eardley, P., and A. Morton,
              "Registry for Performance Metrics", Internet Draft (work
              in progress) draft-ietf-ippm-metric-registry, 2014.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2330]  Paxson, V., Almes, G., Mahdavi, J., and M. Mathis,
              "Framework for IP Performance Metrics", RFC 2330, May
              1998.

   [RFC2679]  Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
              Delay Metric for IPPM", RFC 2679, September 1999.

   [RFC2680]  Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
              Packet Loss Metric for IPPM", RFC 2680, September 1999.

   [RFC2681]  Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip
              Delay Metric for IPPM", RFC 2681, September 1999.

   [RFC3393]  Demichelis, C. and P. Chimento, "IP Packet Delay Variation
              Metric for IP Performance Metrics (IPPM)", RFC 3393,
              November 2002.

   [RFC3432]  Raisanen, V., Grotefeld, G., and A. Morton, "Network
              performance measurement with periodic streams", RFC 3432,
              November 2002.

   [RFC4737]  Morton, A., Ciavattone, L., Ramachandran, G., Shalunov,
              S., and J. Perser, "Packet Reordering Metrics", RFC 4737,
              November 2006.

   [RFC5357]  Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
              Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
              RFC 5357, October 2008.

   [RFC5905]  Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
              Time Protocol Version 4: Protocol and Algorithms
              Specification", RFC 5905, June 2010.

10.2.  Informative References

   [Brow00]   Brownlee, N., "Packet Matching for NeTraMet
              Distributions", March 2000.




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   [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-07 (work in progress), June 2014.

   [RFC1242]  Bradner, S., "Benchmarking terminology for network
              interconnection devices", RFC 1242, July 1991.

   [RFC3611]  Friedman, T., Caceres, R., and A. Clark, "RTP Control
              Protocol Extended Reports (RTCP XR)", RFC 3611, November
              2003.

   [RFC4148]  Stephan, E., "IP Performance Metrics (IPPM) Metrics
              Registry", BCP 108, RFC 4148, August 2005.

   [RFC4566]  Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
              Description Protocol", RFC 4566, July 2006.

   [RFC5472]  Zseby, T., Boschi, E., Brownlee, N., and B. Claise, "IP
              Flow Information Export (IPFIX) Applicability", RFC 5472,
              March 2009.

   [RFC5477]  Dietz, T., Claise, B., Aitken, P., Dressler, F., and G.
              Carle, "Information Model for Packet Sampling Exports",
              RFC 5477, March 2009.

   [RFC5481]  Morton, A. and B. Claise, "Packet Delay Variation
              Applicability Statement", RFC 5481, March 2009.

   [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.

   [RFC6776]  Clark, A. and Q. Wu, "Measurement Identity and Information
              Reporting Using a Source Description (SDES) Item and an
              RTCP Extended Report (XR) Block", RFC 6776, October 2012.

   [RFC6792]  Wu, Q., Hunt, G., and P. Arden, "Guidelines for Use of the
              RTP Monitoring Framework", RFC 6792, November 2012.

   [RFC7003]  Clark, A., Huang, R., and Q. Wu, "RTP Control Protocol
              (RTCP) Extended Report (XR) Block for Burst/Gap Discard
              Metric Reporting", RFC 7003, September 2013.



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Authors' Addresses

   Al Morton
   AT&T Labs
   200 Laurel Avenue South
   Middletown,, NJ  07748
   USA

   Phone: +1 732 420 1571
   Fax:   +1 732 368 1192
   Email: acmorton@att.com
   URI:   http://home.comcast.net/~acmacm/


   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


   Philip Eardley
   British Telecom
   Adastral Park, Martlesham Heath
   Ipswich
   ENGLAND

   Email: philip.eardley@bt.com



















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