IP Performance Metrics (ippm)

Charter for Working Group

The IP Performance Metrics (IPPM) Working Group develops and maintains
standard metrics that can be applied to the quality, performance, and
reliability of Internet data delivery services and applications running
over transport layer protocols (e.g. TCP, UDP) over IP. Specifying network
or lower layer OAM mechanisms is out of scope of the IPPM charter. It also
develops and maintains protocols for the measurement of these metrics.
These metrics are designed such that they can be used by network operators,
end users, or independent testing groups. Metrics developed by the IPPM WG
are intended to provide unbiased quantitative performance measurements and
not a value judgement.

The IPPM WG has produced documents that define specific metrics and
procedures for accurately measuring and documenting these metrics. The
working group will continue advancing the most useful of these metrics
along the standards track, using the guidelines stated in RFC 6576. To the
extent possible, these metrics will be used as the basis for future work on
metrics in the WG.

The WG will seek to develop new metrics and models to more accurately
characterize the network paths under test and/or the performance of
transport and application layer protocols on these paths. The WG will
balance the need for new metrics with the desire to minimize the
introduction of new metrics, and will require that new metric definitions
state how the definition improves on an existing metric definition, or
assesses a property of network performance not previously covered by a
defined metric. Metric definitions will follow the template given in RFC
6390. It is possible that new measurement protocols will be needed to
support new metrics; if this is the case, the working group will be
rechartered to develop these protocols.

Additional methods will be defined for the composition and calibration of
IPPM-defined metrics, as well as active, passive and hybrid measurement
methods for these metrics. In addition, the WG encourages work which
describes the applicability of metrics and measurement methods, especially
to improve understanding of the tradeoffs involved among active, passive,
and hybrid methods.

The WG may update its core framework RFC 2330 as necessary to accommodate
these activities.

The WG has produced protocols for communication among test equipment to
enable the measurement of the one- and two-way metrics (OWAMP and TWAMP
respectively). These protocols will be advanced along the standards track.
The work of the WG will take into account the suitability of measurements
for automation, in order to support large-scale measurement efforts. This
may result in further developments in protocols such as OWAMP and TWAMP.

Agreement about the definitions of metrics and methods of measurement
enables accurate, reproducible, and equivalent results across different
implementations. To this end, the WG will define and maintain a registry of
metric definitions. The WG encourages work which assesses the comparability
of measurements of IPPM metrics with metrics developed elsewhere. The WG
also encourages work which improves the availability of information about
the context in which measurements were taken.

The IPPM WG seeks cooperation with other appropriate standards bodies and
forums to promote consistent approaches and metrics. Within the IETF
process, IPPM metric definitions and measurement protocols will be subject
to as rigorous a scrutiny for usefulness, clarity, and accuracy as other
protocol standards. The IPPM WG will interact with other areas of IETF
activity whose scope intersects with the requirement of these specific
metrics. The WG will, on request, provide input to other IETF working
groups on the use and implementation of these metrics.

Specific near-term milestones include:

1. Advancement of protocols for one- and two-way metrics (OWAMP and TWAMP
respectively) along the standards track.

2. Update of the IPPM framework document (RFC 2330) to reflect experience
with the framework, and to cover planned future metric development.

3. Definition of a registry of metric definitions to improve the
equivalency of metric results across multiple implementations.

4. Publication of a rate measurement problem statement.

5. Publication of documents supporting the use of IPSec to protect OWAMP /
TWAMP.

6. Publication of documents related to model-based TCP bulk transfer
capacity metrics.

Milestones