One document matched: draft-ietf-ippm-metric-registry-05.xml
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<rfc category="bcp" docName="draft-ietf-ippm-metric-registry-05"
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<front>
<title abbrev="Registry for Performance Metrics">Registry for Performance
Metrics</title>
<author fullname="Marcelo Bagnulo" initials="M." surname="Bagnulo">
<organization abbrev="UC3M">Universidad Carlos III de
Madrid</organization>
<address>
<postal>
<street>Av. Universidad 30</street>
<city>Leganes</city>
<region>Madrid</region>
<code>28911</code>
<country>SPAIN</country>
</postal>
<phone>34 91 6249500</phone>
<email>marcelo@it.uc3m.es</email>
<uri>http://www.it.uc3m.es</uri>
</address>
</author>
<author fullname="Benoit Claise" initials="B." surname="Claise">
<organization abbrev="Cisco Systems, Inc.">Cisco Systems,
Inc.</organization>
<address>
<postal>
<street>De Kleetlaan 6a b1</street>
<city>1831 Diegem</city>
<country>Belgium</country>
</postal>
<email>bclaise@cisco.com</email>
</address>
</author>
<author fullname="Philip Eardley" initials="P." surname="Eardley">
<organization abbrev="BT">BT</organization>
<address>
<postal>
<street>Adastral Park, Martlesham Heath</street>
<city>Ipswich</city>
<country>ENGLAND</country>
</postal>
<email>philip.eardley@bt.com</email>
</address>
</author>
<author fullname="Al Morton" initials="A." surname="Morton">
<organization abbrev="AT&T Labs">AT&T Labs</organization>
<address>
<postal>
<street>200 Laurel Avenue South</street>
<city>Middletown, NJ</city>
<country>USA</country>
</postal>
<email>acmorton@att.com</email>
</address>
</author>
<author fullname="Aamer Akhter" initials="A." surname="Akhter">
<organization abbrev="Consultant">Consultant</organization>
<address>
<postal>
<street>118 Timber Hitch</street>
<city>Cary</city>
<region>NC</region>
<code/>
<country>USA</country>
</postal>
<email>aakhter@gmail.com</email>
</address>
</author>
<date year="2015"/>
<abstract>
<t>This document defines the format for the Performance Metrics registry and defines the IANA Registry for
Performance Metrics. This document
also gives a set of guidelines for Registered Performance Metric
requesters and reviewers.</t>
</abstract>
</front>
<middle>
<section title="Introduction">
<t>The IETF specifies and uses Performance Metrics of protocols and
applications transported over its protocols. Performance metrics are
such an important part of the operations of IETF protocols that <xref
target="RFC6390"/> specifies guidelines for their development.</t>
<t>The definition and use of Performance Metrics in the IETF happens in
various working groups (WG), most notably: <list>
<t>The "IP Performance Metrics" (IPPM) WG is the WG primarily
focusing on Performance Metrics definition at the IETF.</t>
<t>The "Metric Blocks for use with RTCP's Extended Report Framework"
(XRBLOCK) WG recently specified many Performance Metrics related to
"RTP Control Protocol Extended Reports (RTCP XR)" <xref
target="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", <xref target="RFC3550"/>.</t>
<t>The "Benchmarking Methodology" WG (BMWG) defined many Performance
Metrics for use in laboratory benchmarking of inter-networking
technologies.</t>
<t>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.</t>
<t>The "Performance Metrics for Other Layers" (PMOL) concluded WG,
defined some Performance Metrics related to Session Initiation
Protocol (SIP) voice quality <xref target="RFC6035"/>.</t>
</list></t>
<t>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.</t>
<t>However, despite the importance of Performance Metrics, there are two
related problems for the industry. First, how to ensure that when one
party requests another party to measure (or report or in some way act
on) a particular Performance Metric, then both parties have exactly the
same understanding of what Performance Metric is being referred to.
Second, how to discover which Performance Metrics have
been specified, so as to avoid developing new Performance Metric that
is very similar, but not quite inter-operable.
The problems can be addressed by creating a registry of performance
metrics. The usual way in which IETF organizes namespaces is with
Internet Assigned Numbers Authority (IANA) registries, and there is
currently no Performance Metrics Registry maintained by the IANA.</t>
<t>This document therefore 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.
Although the Registry format is primarily for use by IANA, any other
organization that wishes to create a Performance Metrics Registry MAY
use the format for its purposes. The authors make no guarantee of the
format's applicability to any possible set of Performance Metrics
envisaged by other organizations. In the rest of this document, unless
we explicitly say so, we will refer to the IANA-maintained Performance
Metrics Registry as simply the Performance Metrics Registry.</t>
</section>
<section title="Terminology">
<t>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 <xref
target="RFC2119"/>.</t>
<!-- <t>The terms Performance Metric is
defined in <xref target="RFC6390"/>, and copied over in this document
for the readers convenience.</t>
-->
<t><list style="hanging">
<t hangText="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, a
database logging time, etc. This definition is consistent with the definition of metric in
<xref target="RFC2330"/> and broader than the definition of performance metric in <xref target="RFC6390"/>.</t>
<t hangText="Registered Performance Metric:">A Registered Performance Metric
is a Performance Metric expressed as an entry
in the Performance Metric Registry, administered by IANA.
Such a performance metric has met all the registry review criteria
defined in this document in order to included in the registry.</t>
<t hangText="Performance Metrics Registry:">The IANA
registry containing Registered Performance Metrics.</t>
<t hangText="Proprietary Registry:">A set of metrics that are
registered in a proprietary registry, as opposed to Performance Metrics Registry.</t>
<t hangText="Performance Metrics Experts:">The Performance Metrics
Experts is a group of designated experts <xref target="RFC5226"/> selected by
the IESG to validate the Performance Metrics before updating the Performance
Metrics Registry. The Performance Metrics Experts work closely with IANA.
</t>
<!-- <t hangText="Performance Metrics Directorate:">The Performance
Metrics Directorate is a directorate that provides guidance for
Performance Metrics development in the IETF. The Performance Metrics
Directorate should be composed of experts in the performance
community, potentially selected from the IP Performance Metrics
(IPPM), Benchmarking Methodology (BMWG), and Performance Metrics for
Other Layers (PMOL) WGs.</t>
-->
<t hangText="Parameter:">An input factor defined as a variable in the definition
of a Performance Metric. 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 to measure 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.
<list>
<t>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.</t>
</list>
</t>
<t hangText="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. A detailed definition of Active Measurement Method is provided in
<xref target="I-D.ietf-ippm-active-passive"/>. Examples of Active Measurement Methods are
the measurement methods for the One way delay metric defined in
<xref target="RFC2679"/> and the one for round trip delay defined in <xref target="RFC2681"/>.</t>
<t hangText="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.
One characteristic of Passive Measurement Methods is that sensitive information
may be observed, and as a consequence, stored in the measurement system.
A detailed definition of Passive Measurement Method is provided in
<xref target="I-D.ietf-ippm-active-passive"/>.
<!-- Some examples include IPFIX <xref target="RFC4656"/>, PSAMP. [RFC 5470], [RFC 5476]--></t>
</list></t>
</section>
<section title="Scope">
<t> This document is meant mainly for two different audiences. 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
RFCs or I-Ds describing it). For the appointed Performance Metrics Experts and
for IANA personnel administering the new IANA Performance Metric
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 organization who are defining a Performance Metric registry
of its own, who can rely on the Performance Metric registry defined in this document.
</t>
<t>This Performance Metric 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 an prior attempt to set up a Performance Metric Registry, and
the reasons why this design was inadequate <xref target="RFC6248"/>.
Finally, this document gives a set of guidelines for requesters and
expert reviewers of candidate Registered Performance Metrics.</t>
<t>This document makes no attempt to populate the Performance Metrics Registry with initial
entries. It does provides a few examples that are merely illustrations and
should not be included in the registry at this point in time.</t>
<t>Based on <xref target="RFC5226"/> Section 4.3, this document is
processed as Best Current Practice (BCP) <xref target="RFC2026"/>.</t>
</section>
<section title="Motivation for a Performance Metrics Registry">
<t>In this section, we detail several motivations for the
Performance Metric Registry.</t>
<section title="Interoperability">
<t>As any IETF registry, the primary use for a registry is to manage a
namespace for its use within one or more protocols. In the
particular case of the Performance Metric 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):
<list
style="symbols">
<t>Control protocol: this type of protocols is used to allow one
entity to request another entity to perform a measurement using a
specific metric defined by the Performance Metrics Registry. One particular example is
the LMAP framework <xref target="RFC7594"/>. Using
the LMAP terminology, the Performance Metrics Registry is used in the LMAP Control
protocol to allow a Controller to request a measurement task to
one or more Measurement Agents. In order to enable this use case,
the entries of the Performance Metric Registry must be well enough defined to
allow a Measurement Agent implementation to trigger a specific
measurement task upon the reception of a control protocol message.
This requirement heavily constrains the type of entries that are
acceptable for the Performance Metric Registry. <!--Further considerations about
this are captured in the Guidelines for metric registry
allocations (cross reference to another section of this document
or to a different document).--></t>
<t>Report protocol: This type of protocols is used to allow an
entity to report measurement results to another entity. By referencing
to a specific Performance Metric 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.</t>
</list>
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 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.
</t>
</section>
<section title="Single point of reference for Performance Metrics">
<t>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 both the IETF
community and external people to have a single list of relevant
Performance Metrics defined by the IETF (and others, where
appropriate). The single list is also an essential aspect of
communication about 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.
</t>
</section>
<section title="Side benefits">
<t>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 would be
comparable even if they are performed by different implementations and
in different networks, as the Performance Metric is properly defined. BCP 176
<xref target="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.</t>
</section>
</section>
<section title="Criteria for Performance Metrics Registration">
<t>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: <list style="numbers">
<t>interpretable by the user.</t>
<t>implementable by the software designer,</t>
<t>deployable by network operators,</t>
<t>accurate, for interoperability and deployment across
vendors,</t>
<t>Operationally useful, so that it has significant industry interest
and/or has seen deployment,</t>
<t> 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.</t>
</list>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.</t>
</section>
<section title="Performance Metric Registry: Prior attempt">
<t>There was a previous attempt to define a metric registry <xref
target="RFC4148">RFC 4148</xref>. However, it was obsoleted by <xref
target="RFC6248">RFC 6248</xref> 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".</t>
<t>A couple of interesting additional quotes from RFC 6248 might help
understand the issues related to that registry. <list style="numbers">
<t>"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."</t>
<t>"The registry structure has been found to be insufficiently
detailed to uniquely identify IPPM metrics."</t>
<t>"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."</t>
</list></t>
<t>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 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.</t>
<section title="Why this Attempt Will Succeed">
<t>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 6), and imposes a group of Performance
Metrics Experts that will provide guidelines to assess if a Performance
Metric is properly specified.</t>
<t>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 Metric Registry value in the protocol, a metric is
properly specified if it is defined well-enough so that it is possible
(and practical) to implement the metric in the measurement agent.
This was the failure of the previous attempt: a registry entry with an
undefined Type-P (section 13 of <xref target="RFC2330">RFC 2330</xref>) allows implementation to be ambiguous.</t>
</section>
</section>
<section anchor="columns" title="Definition of the Performance Metric Registry">
<t>In this section we define the columns of the Performance Metric Registry. This Performance
Metric Registry is applicable to Performance Metrics issued from Active Measurement, Passive Measurement,
and any other form of Performance Metric. Because of that, it may be the case that some of the
columns defined are not applicable for a given type of metric. If this is the 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 addition, it may be possible that, in the future, a new type of metric requires
additional columns. Should that be the case, it is possible to add new columns to the registry. The specification
defining the new column(s) must define how to populate the new column(s) for existing entries.</t>
<t>The columns of the Performance Metric Registry are defined next. The columns are grouped into "Categories" to facilitate the
use of the registry. Categories are described at the 8.x heading level, and columns
are at the 8.x.y heading level. The Figure below illustrates this
organization. An entry (row) therefore gives a complete description of a
Registered Performance Metric.</t>
<t>Each column serves as a check-list item and helps to avoid omissions
during registration and expert review.
<figure>
<artwork><![CDATA[ Registry Categories and Columns, shown as
Category
------------------
Column | Column |
Summary
-------------------------------
Identifier | Name | URIs | Description |
Metric Definition
-----------------------------------------
Reference Definition | Fixed Parameters |
Method of Measurement
---------------------------------------------------------------------
Reference | Packet | Traffic | Sampling | Run-time | Role |
Method | Generation | Filter | Distribution | Parameters | |
| Stream |
Output
-----------------------------
| Type | Reference | Units |
| | Definition | |
Administrative Information
----------------------------------
Status |Request | Rev | Rev.Date |
Comments and Remarks
--------------------
]]></artwork>
</figure></t>
<section title="Summary Category">
<section title="Identifier">
<t>A numeric identifier for the Registered Performance Metric. This
identifier MUST be unique within the Performance Metric Registry.</t>
<t>The Registered Performance Metric unique identifier is a 16-bit
integer (range 0 to 65535). When adding newly Registered Performance
Metrics to the Performance Metric Registry, IANA should assign the
lowest available identifier to the next Registered
Performance Metric.</t>
</section>
<section title="Name">
<t>As the name of a Registered Performance Metric is the first thing a
potential implementor will use when determining whether it is suitable
for a given application, it is important to be as precise and
descriptive as possible. </t>
<t>New names of Registered Performance Metrics:
<list style="numbers">
<t>"MUST be chosen carefully to describe the Registered
Performance Metric and the context in which it will be used."</t>
<t>"MUST be unique within the Performance Metric Registry."</t>
<t>"MUST use capital letters for the first letter of each
component. <!-- except for the first one (aka "camel case")
MARCELO: I am confused by this. If the name of the metric will
start with Act_ or Pas_ which has its first letter capitalized,
then there is no exception, right?--> All other letters MUST be lowercase,
even for acronyms. Exceptions are made for acronyms containing a
mixture of lowercase and capital letters, such as 'IPv4' and
'IPv6'."</t>
<t>MUST use '_' between each component of the Registered
Performance Metric name.</t>
<t>MUST start with prefix Act_ for active measurement Registered
Performance Metric.</t>
<t>MUST start with prefix Pas_ for passive monitoring Registered
Performance Metric.</t>
<t>Other types of Performance Metric should define a proper prefix for
identifying the type.</t>
<!-- <t>MARCELO: I am uncertain whether we should give more guidance
here for the naming convention. In particular, the second
component could be the highest protocol used in the metric (e.g.
UDP, TCP, DNS, SIP, ICMP, IPv4, etc). the third component should
be a descriptive name (like latency, packet loss or similar). the
fourth component could be stream distribution. the fifth component
could be the output type (99mean, 95interval). this is of course
very active metric oriented, would be good if we could figure out
what is the minimum common structure for both passive and active.
TBD. AL COMMENTS: Let's see some examples for passive monitoring.
It may not make sense to have common name components, except for
Act_ and Pas_.</t>
-->
<t>The remaining rules for naming are left for the Performance
Metric Experts to determine as they gather experience, so this is an
area of planned update by a future RFC</t>
</list></t>
<t>An example is "Act_UDP_Latency_Poisson_mean" for a active
monitoring UDP latency metric using a Poisson stream of packets and
producing the mean as output.</t>
<t>Some examples of names of passive metrics might be:
Pas_L3_L4_Octets (Layer 3 and 4 level accounting of bytes observed),
Pas_DNS_RTT (Round Trip Time of in DNS query response of observed
traffic), and Pas_L3_TCP_RTT (Passively observed round trip time
in TCP handshake organized with L3 addresses)</t>
</section>
<section title="URI">
<t>The URIs column MUST contain a URI <xref target="RFC3986"/> that uniquely
identifies the metric. This URI is a URN <xref target="RFC2141"/>. The URI is
automatically generated by prepending the prefix
urn:ietf:params:ippm:metric: to the metric name. The resulting URI
is globally unique. </t>
<t>The URIs column MUST contain a second URI which is a URL <xref target="RFC3986"/>
and uniquely identifies and locates the metric entry so it is
accessible through the Internet.
The URL points to a file containing the information of exactly one registry entry.
The separate files for different entries can be more easily edited and re-used when preparing new entries.
The exact composition of each
metric URL will be determined by IANA, but there will be some
overlap with the URN described above.</t>
</section>
<section title="Description">
<t>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.</t>
</section>
<!-- <section title="Reference Specification(s)">
<t>Registered Performance Metrics that follow the common columns must provide the
reference specification(s) on which the Registered Performance Metric
is based.</t>
</section>-->
</section>
<section title="Metric Definition Category">
<t>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.</t>
<section title="Reference Definition">
<t>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.
</t>
</section>
<section title="Fixed Parameters">
<t>Fixed Parameters are Parameters whose value must be specified
in the Performance Metrics Registry. The measurement system uses these values.</t>
<t>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, for active metrics, Fixed Parameters
determine most or all of the IPPM Framework convention "packets of
Type-P" as described in <xref target="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 <xref target="RFC3550"/>.
Varying MIN_SEQUENTIAL values can alter the loss report and this
value could be set as a Fixed Parameter</t>
<t>In any case, Parameters MUST have well defined names.
For Human readers, the hanging indent style will work, and the
names and definitions that do not appear in the Reference Method
Specification should appear in this column</t>
<t>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.</t>
</section>
</section>
<section title="Method of Measurement Category">
<t>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.</t>
<section title="Reference Method">
<t>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.</t>
<t>Specifically, this section should include pointers to pseudocode or
actual code that could be used for an unambigious implementation.</t>
</section>
<section title="Packet Generation Stream">
<t>This column applies to Performance Metrics that generate traffic for a part of their
Measurement Method purposes including but not necessarily limited to Active metrics.
The generated traffic is referred as stream and this columns describe its characteristics. </t>
<!-- <t>Some metrics, such as those intended for passive monitoring or
RTCP and RTCP-XR metrics, will not specify an entry for this
column.</t> -->
<t>Each entry for this column contains the following information:
<list style="symbols">
<t>Value: The name of the packet stream scheduling
discipline</t>
<t>Reference: the specification where the stream is defined</t>
</list></t>
<t>The packet generation stream
may require parameters such as the 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 wether they will be fixed or will
be an input for the metric.</t>
<t>The simplest example of stream specification is Singleton
scheduling (see <xref target="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 <xref target="RFC2330"/> and
Periodic as described in <xref target="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. </t>
</section>
<section title="Traffic Filter">
<t>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. </t>
<t>The traffic filter itself depends on needs of the metric itself and
a balance of operators measurement needs and user's need for privacy. Mechanics
for conveying the filter criteria might be the BPF (Berkley Packet Filter) or
PSAMP <xref target="RFC5475"/> Property Match Filtering which reuses IPFIX
<xref target="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.
</t>
<t>The traffic filter includes the following information:
<list>
<t>Type: the type of traffic filter used, e.g. BPF, PSAMP, OpenFlow rule, etc. as defined by a normative reference</t>
<t>Value: the actual set of rules expressed </t>
</list></t>
</section>
<section title="Sampling Distribution">
<t>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:
<list>
<t>Value: the name of the sampling distribution</t>
<t>Reference definition: pointer to the specification where the sampling distribution is properly defined.</t>
</list></t>
<t>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 wether they will be fixed or will
be an input for the metric.</t>
<t>Sampling and Filtering Techniques for IP Packet Selection are documented in the PSAMP (Packet Sampling)
<xref target="RFC5475"/>, while the Framework for Packet Selection and Reporting, <xref target="RFC5474"/>
provides more background information. The sampling distribution parameters might be expressed in terms of the
Information Model for Packet Sampling Exports, <xref target="RFC5477"/>, and the Flow Selection Techniques,
<xref target="RFC7014"/>.</t>
</section>
<section title="Run-time Parameters">
<t>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).</t>
<t>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.</t>
<t>Parameters MUST have well defined names.
For Human readers, the hanging indent style will work, and the
names and definitions that do not appear in the Reference Method
Specification should appear in this column.</t>
<t>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 <xref target="RFC6991"/>. The actual encoding(s) used must be explicitly defined
for each Run-time parameter.</t>
<t>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.</t>
</section>
<section title="Role">
<t>In some method of measurements, there may be several roles defined e.g. on a one-way packet delay active measurement, there is
one measurement agent that generates the packets and the other one that receives the packets. This column contains the name of the
role for this particular entry. In the previous example, there should be two entries in the registry, one for each role, so that when
a measurement agent is instructed to perform the one way delay source metric know that it is supposed to generate packets. The values
for this field are defined in the reference method of measurement.</t>
</section>
</section>
<section title="Output Category">
<t>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.</t>
<t>Some metrics embed one specific statistic in the reference metric
definition, while others allow several output types or
statistics.</t>
<section title="Type">
<t>This column contain the name of the output type.
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").</t>
</section>
<!--
<section title="Data Format">
<t>This column provides the data format for the output. It is provided to simplify the communication with
collection systems and implementation of measurement
devices.</t>
</section>
-->
<section title="Reference Definition">
<t>This column contains a pointer to the specification where the output type is
defined</t>
</section>
<section title="Metric Units">
<t>The measured results must be expressed using some standard
dimension or units of measure. This column provides the units.</t>
<t>When a sample of singletons (see <xref target="RFC2330"/> for
definitions of these terms) is collected, this entry will specify
the units for each measured value.</t>
</section>
</section>
<section title="Administrative information">
<section title="Status">
<t>The status of the specification of this Registered Performance
Metric. Allowed values are 'current' and 'deprecated'. All newly
defined Information Elements have 'current' status.</t>
</section>
<section title="Requester">
<t>The requester for the Registered Performance Metric. The requester
MAY be a document, such as RFC, or person.</t>
</section>
<section title="Revision">
<t>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.</t>
</section>
<section title="Revision Date">
<t>The date of acceptance or the most recent revision for the
Registered Performance Metric.</t>
</section>
</section>
<section title="Comments and Remarks">
<t>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.</t>
</section>
</section>
<section title="The Life-Cycle of Registered Performance Metrics">
<t>Once a Performance Metric or set of Performance Metrics has been
identified for a given application, candidate Performance Metrics Registry entry
specifications in accordance with <xref target="columns"/> are submitted to IANA to
follow the process for review by the Performance Metric Experts, as
defined below. This process is also used for other changes to the
Performance Metric Registry, such as deprecation or revision, as
described later in this section.</t>
<t>It is also 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 WG mailing list.</t>
<section title="Adding new Performance Metrics to the Performance Metrics Registry">
<t>Requests to change Registered Performance Metrics in the Performance Metric
Registry are submitted to IANA, which
forwards the request to a designated group of experts (Performance
Metric Experts) appointed by the IESG; these are the reviewers called
for by the Expert Review RFC5226 policy defined for the Performance
Metric Registry. The Performance Metric Experts review the request for
such things as compliance with this document, compliance with other
applicable Performance Metric-related RFCs, and consistency with the
currently defined set of Registered Performance Metrics.</t>
<t>Authors are expected to review compliance with the specifications
in this document to check their submissions before sending them to
IANA.</t>
<t>The Performance Metric Experts should endeavor to complete referred
reviews in a timely manner. If the request is acceptable, the
Performance Metric Experts signify their approval to IANA, which
updates the Performance Metric Registry. If the request is not
acceptable, the Performance Metric Experts can coordinate with the
requester to change the request to be compliant. The Performance
Metric Experts may also choose in exceptional circumstances to reject
clearly frivolous or inappropriate change requests outright.</t>
<t>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 with IETF consensus require
IETF consensus for revision or deprecation.</t>
<t>Decisions by the Performance Metric Experts may be appealed as in
Section 7 of RFC5226.</t>
</section>
<section title="Revising Registered Performance Metrics">
<!-- <t>Requests to revise the Performance Metric Registry or a linked
sub-registry are submitted to IANA, which forwards the request to a
designated group of experts (Performance Metric Experts) appointed by
the IESG; these are the reviewers called for by the Expert Review
[RFC5226] policy defined for the Performance Metric Registry. The
Performance Metric Experts review the request for such things as
compliance with this document, compliance with other applicable
Performance Metric-related RFCs, and consistency with the currently
defined set of Registered Performance Metrics.</t>
-->
<t>A request for Revision is only permissible when the 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).</t>
<t>The purpose of the Status field in the Performance Metric Registry
is to indicate whether the entry for a Registered Performance Metric is 'current'
or 'deprecated'.</t>
<t>In addition, no policy is defined for revising IANA Performance
Metric entries or addressing errors therein. To be certain, changes
and deprecations within the Performance Metric Registry are not
encouraged, and should be avoided to the extent possible. However, in
recognition that change is inevitable, the provisions of this section
address the need for revisions.</t>
<t>Revisions are initiated by sending a candidate Registered
Performance Metric definition to IANA, as in Section 8, identifying
the existing Performance Metrics Registry entry.</t>
<t>The primary requirement in the definition of a policy for managing
changes to existing Registered Performance Metrics is avoidance of
interoperability problems; Performance Metric Experts must work to
maintain interoperability above all else. Changes to Registered
Performance Metrics may only be done in an
inter-operable way; necessary changes that cannot be done in a way to
allow interoperability with unchanged implementations must result in
the creation of a new Registered Performance Metric and possibly the deprecation of the earlier metric.</t>
<t>A change to a Registered Performance Metric is held to be
backward-compatible only when: <list style="numbers">
<t>"it involves the correction of an error that is obviously only
editorial; or"</t>
<t>"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"</t>
<t>"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"</t>
<t>"it harmonizes with an external reference that was itself
corrected."</t>
<!-- <t>"BENOIT: NOTE THAT THERE ARE MORE RULES IN RFC 7013 SECTION 5
BUT THEY WOULD ONLY APPLY TO THE ACTIVE/PASSIVE DRAFTS. TO BE
DISCUSSED."</t> -->
</list></t>
<t>If an Performance Metric revision is deemed permissible by the
Performance Metric Experts, according to the rules in this document,
IANA makes the change in the Performance Metric Registry. The
requester of the change is appended to the requester in the
Performance Metrics Registry.</t>
<t>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.</t>
<t>When a revised Registered Performance Metric is accepted into the
Performance Metric 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.</t>
<t>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.</t>
<t>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 is changed to
"Deprecated".</t>
</section>
<section title="Deprecating Registered Performance Metrics">
<t>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:
<list style="numbers">
<t>"the Registered Performance Metric definition has an error or
shortcoming that cannot be permissibly changed as in Section
Revising Registered Performance Metrics; or"</t>
<t>"the deprecation harmonizes with an external reference that was
itself deprecated through that reference's accepted deprecation
method; or"</t>
</list></t>
<t>A request for deprecation is sent to IANA, which passes it to the
Performance Metric Expert for review. When deprecating an
Performance Metric, the Performance Metric description in the
Performance Metric Registry must be updated to explain the
deprecation, as well as to refer to any new Performance Metrics
created to replace the deprecated Performance Metric.</t>
<t>The revision number of a Registered Performance Metric is
incremented upon deprecation, and the revision Date updated, as with
any revision.</t>
<t>The use of deprecated Registered Performance Metrics should result in a log
entry or human-readable warning by the respective application.</t>
<t>Names and Metric ID of deprecated Registered Performance Metrics must not be
reused.</t>
<t>The deprecated entries are kept with all fields unmodified,
except the version, revision date, and the status field
(changed to "Deprecated").</t>
</section>
</section>
<!-- <section title="Performance Metric Registry and other Registries">
<t>BENOIT: TBD.</t>
<t>THE BASIC IDEA IS THAT PEOPLE COULD DIRECTLY DEFINE PERF. METRICS IN
OTHER EXISTING REGISTRIES, FOR SPECIFIC PROTOCOL/ENCODING. EXAMPLE:
IPFIX. IDEALLY, ALL PERF. METRICS SHOULD BE DEFINED IN THIS REGISTRY AND
REFERS TO FROM OTHER REGISTRIES.</t>
</section>
-->
<section title="Security considerations">
<t>This draft doesn't introduce any new security considerations for the
Internet. However, the definition of Performance Metrics may introduce
some security concerns, and should be reviewed with security in
mind.</t>
</section>
<section title="IANA Considerations">
<t>This document specifies the procedure for Performance Metrics
Registry setup. IANA is requested to create a new registry for
Performance Metrics called "Registered Performance Metrics" with the columns defined in <xref target="columns"/>.</t>
<t>New assignments for Performance Metric Registry will be administered
by IANA through Expert Review [RFC5226], i.e., review by one of a group
of experts, the Performance Metric Experts, appointed by the IESG upon
recommendation of the Transport Area Directors. The experts can be
initially drawn from the Working Group Chairs and document editors of
the Performance Metrics Directorate among other sources of experts.</t>
<t>The Identifier values from 64512 to 65536 are reserved for private use.
The name starting with the prefix Priv- are reserved for private use.</t>
<t>This document requests the allocation of the URI prefix urn:ietf:params:ippm:metric
for the purpose of generating URIs for Registered Performance Metrics.</t>
</section>
<section title="Acknowledgments">
<t>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.</t>
</section>
<!--
<section title="Appendix: Examples">
<section title="Example IPPM Active Registry Entry">
<t>This section is Informational.</t>
<t>This section gives an example registry entry for the active metric
described in <xref target="RFC3393"/>, on Packet Delay Variation.</t>
<section title="Registry Indexes">
<t>This category includes multiple indexes to the Registered Performance Metrics,
the element ID and metric name.</t>
<section title="Identifier">
<t>An integer having enough digits to uniquely identify each entry
in the Registry.</t>
</section>
<section title="Name">
<t>A metric naming convention is TBD.</t>
<t>One possibility based on IPPM's framework is:</t>
<t>Act_IP_UDP_One-way-pdv_95th-percentile_Poisson</t>
</section>
<section title="URI">
<t>Prefix urn:ietf:params:performance:metric</t>
</section>
<section title="Status">
<t>current</t>
</section>
<section title="Requestor">
<t>Alcelip Mornuley</t>
</section>
<section title="Revision">
<t>1.0</t>
</section>
<section title="Revision Date">
<t>2014-07-04</t>
</section>
<section title="Description">
<t>An assessment of packet delay variation with respect to the
minimum delay observed on the stream.</t>
</section>
<section title="Reference Specification(s)">
<t><xref target="RFC2330"/><xref target="RFC3393"/><xref
target="RFC5481"/><xref target="RFC5905"/></t>
</section>
</section>
<section title="Metric Definition">
<t>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.</t>
<section title="Reference Definition">
<t>See sections 2.4 and 3.4 of <xref target="RFC3393"/>. Singleton
delay differences measured are referred to by the variable name
"ddT".</t>
</section>
<section title="Fixed Parameters">
<t>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.</t>
<t><list style="symbols">
<t>F, a selection function defining unambiguously the packets
from the stream selected for the metric. See section 4.2 of
<xref target="RFC5481"/> for the PDV form.</t>
<t>L, a packet length in bits. L = 200 bits.</t>
<t>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.</t>
<t>Type-P, as defined in <xref target="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).</t>
</list></t>
</section>
</section>
<section title="Method of Measurement">
<t>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.</t>
<section title="Reference Method">
<t>See section 2.6 and 3.6 of <xref target="RFC3393"/> for singleton
elements.</t>
</section>
<section title="Stream Type and Stream Parameters">
<t>Poisson distributed as described in <xref target="RFC2330"/>,
with the following Parameters.</t>
<t><list style="symbols">
<t>lambda, a rate in reciprocal seconds (for Poisson Streams).
lambda = 1 packet per second</t>
<t>Upper limit on Poisson distribution (values above this limit
will be clipped and set to the limit value). Upper limit = 30
seconds.</t>
</list></t>
</section>
<section title="Traffic Filter">
<t>NA</t>
</section>
<section title="Measurement Timing">
<t>NA</t>
</section>
<section title="Output Type and Data Format">
<t>See section 4.3 of <xref target="RFC3393"/> for details on the
percentile statistic.</t>
<t>The percentile = 95.</t>
<t>Data format is a 32-bit unsigned floating point value.</t>
<t>Individual results (singletons) should be represented by the
following triple</t>
<t><list style="symbols">
<t>T1 and T2, times as described below in the Run-time
parameters section.</t>
<t>ddT as defined in section 2.4 of <xref target="RFC3393"/></t>
</list>if needed. The result format for ddT is *similar to* the
short format in <xref target="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.</t>
</section>
<section title="Metric Units">
<t>See section 3.3 of <xref target="RFC3393"/> for singleton
elements.</t>
<t><xref target="RFC2330"/> recommends that when a time is given, it
will be expressed in UTC.</t>
<t>The timestamp format (for T, Tf, etc.) is the same as in <xref
target="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.</t>
</section>
<section title="Run-time Parameters and Data Format">
<t>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
Registered Performance Metrics, some of the parameters below may be designated as
Fixed Parameters instead.</t>
<t><list style="symbols">
<t>Src, the IP address of a host (32-bit value for IPv4, 128-bit
value for IPv6)</t>
<t>Dst, the IP address of a host (32-bit value for IPv4, 128-bit
value for IPv6)</t>
<t>T, a time (start of test interval, 128-bit NTP Date Format,
see section 6 of <xref target="RFC5905"/>)</t>
<t>Tf, a time (end of test interval, 128-bit NTP Date Format,
see section 6 of <xref target="RFC5905"/>)</t>
<t>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 <xref target="RFC5905"/>).</t>
<t>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 <xref target="RFC5905"/>).</t>
<t>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 <xref target="RFC5905"/>).</t>
</list></t>
</section>
</section>
<section title="Comments and Remarks">
<t>Lost packets represent a challenge for delay variation metrics. See
section 4.1 of <xref target="RFC3393"/> and the delay variation
applicability statement<xref target="RFC5481"/> for extensive analysis
and comparison of PDV and an alternate metric, IPDV.</t>
</section>
</section>
<section title="Example RTCP-XR Registry Entry">
<t>This section is Informational.</t>
<t>This section gives an example registry entry for the end-point metric
described in <xref target="RFC7003"/>, for RTCP-XR Burst/Gap
Discard Metric reporting.</t>
<section title="Registry Indexes">
<t>This category includes multiple indexes to the Registered Performance Metrics,
the element ID and metric name.</t>
<section title="Identifier">
<t>An integer having enough digits to uniquely identify each entry
in the Registry.</t>
</section>
<section title="Name">
<t>A metric naming convention is TBD.</t>
</section>
<section title="URI">
<t>Prefix urn:ietf:params:performance:metric</t>
</section>
<section title="Status">
<t>current</t>
</section>
<section title="Requestor">
<t>Alcelip Mornuley</t>
</section>
<section title="Revision">
<t>1.0</t>
</section>
<section title="Revision Date">
<t>2014-07-04</t>
</section>
<section title="Description">
<t>TBD.</t>
</section>
<section title="Reference Specification(s)">
<t><xref target="RFC3611"/><xref target="RFC4566"/>
<xref target="RFC6776"/><xref target="RFC6792"/>
<xref target="RFC7003"/></t>
</section>
</section>
<section title="Metric Definition">
<t>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
<xref target="RFC7003"/> provides the reference information for this
category.</t>
<section title="Reference Definition">
<t>Packets Discarded in Bursts:</t>
<t>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.</t>
</section>
<section title="Fixed Parameters">
<t>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.</t>
<t>Threshold: 8 bits, set to value = 3 packets.</t>
<t>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].</t>
<t>Interval Metric flag: 2 bits, set to value 11=Cumulative
Duration</t>
<t>This field is used to indicate whether the burst/gap discard
metrics are Sampled, Interval, or Cumulative metrics <xref target="RFC6792"/>:</t>
<t>I=10: Interval Duration - the reported value applies to the most
recent measurement interval duration between successive metrics
reports.</t>
<t>I=11: Cumulative Duration - the reported value applies to the
accumulation period characteristic of cumulative measurements.</t>
<t>Senders MUST NOT use the values I=00 or I=01.</t>
</section>
</section>
<section title="Method of Measurement">
<t>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 <xref target="RFC7003"/> and its supporting
references. Relevant information is repeated below, although there
appears to be no section titled "Method of Measurement" in <xref
target="RFC7003"/>.</t>
<section title="Reference Method">
<t>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 <xref target="RFC6776"/>, which
describes measurement periods in use (see <xref target="RFC6776"/>,
Section 4.2).</t>
<t>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.</t>
</section>
<section title="Stream Type and Stream Parameters">
<t>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.</t>
</section>
<section title="Traffic Filter">
<t>NA</t>
</section>
<section title="Measurement Timing">
<t>NA</t>
</section>
<section title="Output Type and Data Format">
<t>The output type defines the type of result that the metric
produces.</t>
<t><list style="symbols">
<t>Value: Packets Discarded in Bursts</t>
<t>Data Format: 24 bits</t>
<t>Reference: Section 3.2 of <xref target="RFC7003"/></t>
</list></t>
</section>
<section title="Metric Units">
<t>The measured results are apparently expressed in packets,
although there is no section of <xref target="RFC7003"/> titled
"Metric Units".</t>
</section>
<section title="Run-time Parameters and Data Format">
<t>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).</t>
<t>The Data Format of each Run-time Parameter SHALL be specified in
this column, to simplify the control and implementation of
measurement devices.</t>
<t>SSRC of Source: 32 bits As defined in Section 4.1 of
[RFC3611].</t>
<t>SDP Parameters: As defined in <xref target="RFC4566"/></t>
<t>Session description v= (protocol version number, currently only
0)</t>
<t>o= (originator and session identifier : username, id, version
number, network address)</t>
<t>s= (session name : mandatory with at least one UTF-8-encoded
character)</t>
<t>i=* (session title or short information) u=* (URI of
description)</t>
<t>e=* (zero or more email address with optional name of
contacts)</t>
<t>p=* (zero or more phone number with optional name of
contacts)</t>
<t>c=* (connection information—not required if included in all
media)</t>
<t>b=* (zero or more bandwidth information lines) One or more Time
descriptions ("t=" and "r=" lines; see below)</t>
<t>z=* (time zone adjustments)</t>
<t>k=* (encryption key)</t>
<t>a=* (zero or more session attribute lines)</t>
<t>Zero or more Media descriptions (each one starting by an "m="
line; see below)</t>
<t>m= (media name and transport address)</t>
<t>i=* (media title or information field)</t>
<t>c=* (connection information — optional if included at
session level)</t>
<t>b=* (zero or more bandwidth information lines)</t>
<t>k=* (encryption key)</t>
<t>a=* (zero or more media attribute lines — overriding the
Session attribute lines)</t>
<t>An example Run-time SDP description follows:</t>
<t>v=0</t>
<t>o=jdoe 2890844526 2890842807 IN IP4 192.0.2.5</t>
<t>s=SDP Seminar i=A Seminar on the session description protocol</t>
<t>u=http://www.example.com/seminars/sdp.pdf e=j.doe@example.com
(Jane Doe)</t>
<t>c=IN IP4 233.252.0.12/127</t>
<t>t=2873397496 2873404696</t>
<t>a=recvonly</t>
<t>m=audio 49170 RTP/AVP 0</t>
<t>m=video 51372 RTP/AVP 99</t>
<t>a=rtpmap:99 h263-1998/90000</t>
</section>
</section>
<section title="Comments and Remarks">
<t>TBD.</t>
</section>
</section>
<section title="Example Generalized Passive Octet Count Entry">
<t>This section gives an example registry entry for a generalized the passive metric
octetDeltaCount described in the IPFIX registry"/>.</t>
<section title="Registry Indexes">
<t>This category includes multiple indexes to the Registered Performance Metrics,
the element ID and metric name.</t>
<section title="Element Identifier">
<t>An integer having enough digits to uniquely identify each entry
in the Registry.</t>
<t>TBD by IANA.</t>
</section>
<section title="Metric Name">
<t>A metric naming convention is TBD.</t>
<t>Pas_IP_Octet-Delta-General</t>
</section>
<section title="URI">
<t>urn:ietf:params:performance:metric-something</t>
</section>
<section title="Status">
<t>Current</t>
</section>
<section title="Requester">
<t>TBD</t>
</section>
<section title="Revision">
<t>0</t>
</section>
<section title="Revision Date">
<t>TBD</t>
</section>
<section title="Metric Description">
<t>A delta count of the number of octets observed.
</t>
</section>
<section title="Reference Specification(s)">
<t>octetDeltaCount described in the IPFIX registry.</t>
</section>
</section>
<section title="Metric Definition">
<t>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.</t>
<section title="Reference Definition">
<t>octetDeltaCount described in the IPFIX registry.</t>
</section>
<section title="Fixed Parameters">
<t> As this is the generalised version of the IP delta count
metric, there are no fixed parameters.</t>
</section>
</section>
<section title="Method of Measurement">
<section title="Reference Implementation">
<t>For <metric>.</t>
<t><section reference></t>
<t/>
</section>
<section title="Stream Type and Stream Parameters">
<t>NA</t>
</section>
<section title="Traffic Filter Criteria">
<t>
This measurement only covers IP packets and the IP
payload (including the IP header) of these packets.
Non-IP packets (BPDUs, ISIS) will not be accounted.
Layer 2 overhead (Ethernet headers, MPLS, QinQ, etc.) will
also not be represented in the measurement.
</t>
</section>
<section title="Measurement Timing">
<t>
This is a continous measurement of the IP octets
seen in the traffic selection scope (run-time parameter).
</t>
<t>The measurement interval is a run time parameter.
</t>
<t>There is no sampling.</t>
</section>
<section title="Output Type(s) and Data Format">
<t>It is possible that multiple observation intervals are reported
in a single report. In such a case concatination of the interval reports
(deltaOctetCount, start-time, end-time) is allowed. </t>
<t>The delta octet count metric reports a observation
start time and end time. </t>
<t><list style="symbols">
<t>Value: observation-start-time and observation-end-time</t>
<t>Data Format: 64-bit NTP Time-stamp Format</t>
<t>Reference: section 6 of
<xref target="RFC5905"/></t>
</list></t>
</section>
<section title="Metric Units">
<t>The measured results are expressed in octets with
a data format of unsigned64 as described in the IPFIX registry.</t>
</section>
<section title="Run-time Parameters and Data Format">
<t>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.</t>
<t><list style="symbols">
<t>samplingTimeInterval, length of time a single report covers. unsigned32 microseconds <xref target="RFC5477"/> </t>
<t>observationInterface, ifindex of interface to monitor. -1 represents all interfaces. -2 representing WAN facing and -3 represents LAN facing. unsigned32.</t>
<t>observation direction, unsigned8 where 0 represents incoming traffic on interface, 1 outgoing and 2 represents both incoming and outgoing. </t>
</list></t>
</section>
</section>
<section title="Comments and Remarks">
<t>Additional (Informational) details for this entry</t>
</section>
</section>
<section title="Example 5min Passive Egress IP Destination Octet Count Entry on WAN Interface">
<t>tbd</t>
<t>This section is Informational.</t>
<t>This section gives an example registry entry for the passive accounting of byte counts and
destination address on outgoing WAN IP. The byte count and IP address is based on octetDeltaCount
and destinationIPv4Address, as described in the IPFIX registry.</t>
<section title="Registry Indexes">
<t>This category includes multiple indexes to the Registered Performance Metrics,
the element ID and metric name.</t>
<section title="Element Identifier">
<t>An integer having enough digits to uniquely identify each entry
in the Registry.</t>
<t>TBD by IANA.</t>
</section>
<section title="Metric Name">
<t>A metric naming convention is TBD.</t>
<t>Pas_IPDst-Octet-Delta-WAN-egress</t>
</section>
<section title="URI">
<t>urn:ietf:params:performance:Pas_IPDst-Octet-Delta-WAN-egress</t>
</section>
<section title="Status">
<t>Current</t>
</section>
<section title="Requester">
<t>The IPPM working group</t>
</section>
<section title="Revision">
<t>0</t>
</section>
<section title="Revision Date">
<t>Today</t>
</section>
<section title="Metric Description">
<t>This example passive measurement registry entry measures per-destination IP bytes sent.
The byte count and IP address are based on octetDeltaCount and destinationIPv4Address, as
described in IPFIX Registry. This metric can be used to understand outgoing
top destinations per agent, saturation of link utilization towards a single destination and
other bandwidth utilization uses.</t>
</section>
<section title="Reference Specification(s)">
<t>octetDeltaCount described in IPFIX registry</t>
</section>
<section title="Fixed Parameters">
<t>Measurement Interval = 300 sec</t>
<t>IPFIX Template = KEY:destinationIPv4Address,egressInterface=WAN Value:octetDeltaCount </t>
</section>
<section title="Traffic Filter">
<t>PSAMP: "ipVersion == 4 AND egressInterface==WAN"</t>
</section>
<section title="Sampling Distribution">
<t>No sampling</t>
</section>
<section title="Run-time Parameters">
<t>None</t>
</section>
</section>
<section title="Example 5min Passive Egress Octet Count Entry on WAN Interface">
<t>tbd</t>
<t>This section is Informational.</t>
<t>This section gives an example registry entry for accounting of outgoing WAN IP
traffic the passive metric in terms of octetDeltaCount, as described in the IPFIX registry.</t>
<section title="Registry Indexes">
<t>This category includes multiple indexes to the Registered Performance Metrics,
the element ID and metric name.</t>
<section title="Element Identifier">
<t>An integer having enough digits to uniquely identify each entry
in the Registry.</t>
<t>TBD by IANA.</t>
</section>
<section title="Metric Name">
<t>A metric naming convention is TBD.</t>
<t>Pas_IP-Octet-Delta-WAN-egress</t>
</section>
<section title="URI">
<t>urn:ietf:params:performance:metric-something</t>
</section>
<section title="Status">
<t>Current</t>
</section>
<section title="Requester">
<t>TBD</t>
</section>
<section title="Revision">
<t>0</t>
</section>
<section title="Revision Date">
<t>TBD</t>
</section>
<section title="Metric Description">
<t>A delta count of the number of octets observed outgoing on WAN interface.
</t>
</section>
<section title="Reference Specification(s)">
<t>octetDeltaCount described in the IPFIX registry</t>
</section>
</section>
<section title="Metric Definition">
<t>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.</t>
<section title="Reference Definition">
<t>octetDeltaCount described in the IPFIX registry"/></t>
</section>
<section title="Fixed Parameters">
<t> As this is a specific version of Pas_IP-Octet-Delta-General that
performs metering of all outgoing WAN traffic.</t>
<t><list style="symbols">
<t>samplingTimeInterval= 300000000, length of time a single report covers. unsigned32 microseconds <xref target="RFC5477"/> </t>
<t>observationInterface= -2, ifindex of interface to monitor. -1 represents all interfaces. -2 representings WAN facing and -3 represnets LAN facing. unsigned32.</t>
<t>observation direction= 1, unsigned8 where 0 represents incoming traffic on interface, 1 outgoing and 2 represents both incoming and outgoing. </t>
</list></t>
</section>
</section>
<section title="Method of Measurement">
<section title="Reference Implementation">
<t>For <metric>.</t>
<t><section reference></t>
<t/>
</section>
<section title="Stream Type and Stream Parameters">
<t>NA</t>
</section>
<section title="Traffic Filter Criteria">
<t>
This measurement only covers IP packets observed in the
WAN outgoing direction. The bytes counted are the IP
payload (including the IP header) of these packets.
Non-IP packets (BPDUs, ISIS) will not be accounted.
Layer 2 overhead (Ethernet headers, MPLS, QinQ, etc.) will
also not be represented in the measurement.
</t>
</section>
<section title="Measurement Timing">
<t>
This is a continous measurement of the IP octets
seen in the traffic selection scope (run-time parameter),
each of a 5 minute duration.
</t>
<t>There is no sampling.</t>
</section>
<section title="Output Type(s) and Data Format">
<t>It is possible that multiple observation intervals are reported
in a single report. In such a case concatination of the interval reports
(deltaOctetCount, start-time, end-time) is allowed. </t>
<t>The delta octet count metric reports a observation
start time and end time. </t>
<t><list style="symbols">
<t>Value: observation-start-time and observation-end-time</t>
<t>Data Format: 64-bit NTP Time-stamp Format</t>
<t>Reference: section 6 of
<xref target="RFC5905"/></t>
</list></t>
</section>
<section title="Metric Units">
<t>The measured results are expressed in octets with
a data format of unsigned64 as described in the IPFIX registry</t>
</section>
<section title="Run-time Parameters and Data Format">
<t>There are no run-time parameters for this registry entry.</t>
</section>
</section>
<section title="Comments and Remarks">
<t>Additional (Informational) details for this entry</t>
</section>
</section>
<section title="Example Passive RTP Lost Packet Count">
<t>tbd</t>
</section>
<section title="Example BLANK Registry Entry">
<t>This section is Informational. (?)</t>
<t>This section gives an example registry entry for the <type of
metric and specification reference> .</t>
<section title="Registry Indexes">
<t>This category includes multiple indexes to the Registered Performance Metrics,
the element ID and metric name.</t>
<section title="Identifier">
<t>An integer.</t>
</section>
<section title="Name">
<t>A metric naming convention is TBD.</t>
</section>
<section title="URI">
<t>Prefix urn:ietf:params:performance:metric</t>
</section>
<section title="Status">
<t>current</t>
</section>
<section title="Requestor">
<t>name or RFC, etc.</t>
</section>
<section title="Revision">
<t>1.0</t>
</section>
<section title="Revision Date">
<t>YYYY-MM-DD</t>
</section>
<section title="Description">
<t>TBD.</t>
</section>
<section title="Reference Specification(s)">
<t>RFC...</t>
</section>
</section>
<section title="Metric Definition">
<t>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.</t>
<t><possible section reference>.</t>
<section title="Reference Definition">
<t/>
<t/>
</section>
<section title="Fixed Parameters">
<t>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.</t>
<t><list fixed parameters></t>
</section>
</section>
<section title="Method of Measurement">
<t>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.</t>
<section title="Reference Method">
<t>For <metric>.</t>
<t><section reference></t>
<t/>
</section>
<section title="Stream Type and Stream Parameters">
<t><list of stream parameters>.</t>
<t><references></t>
<t/>
</section>
<section title="Traffic Filter Criteria">
<t>
<list filter criteria limitations and allowances >
</t>
</section>
<section title="Measurement Timing">
<t>
< list timing requirements and limitations >
</t>
</section>
<section title="Output Type and Data Format">
<t>The output type defines the type of result that the metric
produces.</t>
<t><list style="symbols">
<t>Value:</t>
<t>Data Format: (There may be some precedent to follow here, but
otherwise use 64-bit NTP Timestamp Format, see section 6 of
<xref target="RFC5905"/>).</t>
<t>Reference: <section reference></t>
</list></t>
</section>
<section title="Metric Units">
<t>The measured results are expressed in <units>,</t>
<t><section reference>.</t>
</section>
<section title="Run-time Parameters and Data Format">
<t>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.</t>
<t><list of run-time parameters></t>
<t><reference(s)>.</t>
</section>
</section>
<section title="Comments and Remarks">
<t>Additional (Informational) details for this entry</t>
</section>
</section>
</section>
-->
</middle>
<back>
<references title="Normative References">
<?rfc include="reference.RFC.2026"?>
<?rfc include="reference.RFC.2119"?>
<?rfc include='reference.RFC.2141'?>
<?rfc include='reference.RFC.2330'?>
<?rfc include='reference.RFC.3986'?>
<?rfc include='reference.RFC.4148'?>
<?rfc include="reference.RFC.5226"?>
<?rfc include='reference.RFC.6248'?>
<?rfc include="reference.RFC.6390"?>
<?rfc include='reference.RFC.6576'?>
</references>
<references title="Informative References">
<?rfc include="reference.RFC.2679"?>
<?rfc include="reference.RFC.2681"?>
<?rfc include="reference.RFC.3393"?>
<?rfc include="reference.RFC.3432"?>
<?rfc include="reference.RFC.3550"?>
<?rfc include="reference.RFC.3611"?>
<?rfc include="reference.RFC.4566"?>
<?rfc include="reference.RFC.5474"?>
<?rfc include="reference.RFC.5475"?>
<?rfc include="reference.RFC.5477"?>
<?rfc include="reference.RFC.5481"?>
<?rfc include="reference.RFC.5905"?>
<?rfc include="reference.RFC.6035"?>
<?rfc include="reference.RFC.6776"?>
<?rfc include="reference.RFC.6792"?>
<?rfc include="reference.RFC.7003"?>
<?rfc include="reference.RFC.7012"?>
<?rfc include="reference.RFC.7014"?>
<?rfc include='reference.RFC.7594'?>
<?rfc include='reference.I-D.ietf-ippm-active-passive"?>
<?rfc include='reference.RFC.6991'?>
</references>
</back>
</rfc>
| PAFTECH AB 2003-2026 | 2026-04-24 04:28:15 |