RFC 9097 §6: Maximum IP-Layer Capacity Metric Definitions (Statistics)
The 18 Requirements of RFC 9097 §6, each quoted from the RFC with its state and the tests that prove it. Conformance explains the states.
| State | Requirements |
|---|---|
| Tested | 12 |
| Operational | 3 |
| Not applicable | 3 |
RFC9097-6.2-1
Not applicable
This section lists the REQUIRED input factors to specify the metric, beyond those listed in Section 4.
Note: The section adds no Parameters.
RFC9097-6.3-1
Not applicable
This section defines the REQUIRED aspects of the Maximum IP-Layer Capacity Metric (unless otherwise indicated) for measurements between specified Source and Destination hosts:
Note: An introduction to the section’s Requirements, each recorded with its own ID; nothing to do beyond them.
RFC9097-6.3-L1
Tested
Define the Maximum IP-Layer Capacity, Maximum_C(T,I,PM), to be the maximum number of IP-Layer bits n0[dtn,dtn+1] divided by dt that can be transmitted in packets from the Src host and correctly received by the Dst host, over all dt-length intervals in [T,T+I] and meeting the PM criteria.
Note: Maximum IP-Layer Capacity; a definition, but the one the results compute.
Conformance Records: shallow-queue-search-alternates-at-the-bottleneck, duplicates-count-as-received, empty-sub-interval-meets-no-criterion, json-at-max-is-the-maximum.
Proving tests:
crates/udpstp/src/results.rs::a_watchdog_ended_test_with_two_capacity_modescrates/udpstp/tests/netns.rs::downstream_and_upstream_tests_measure_the_bottleneckcrates/udpstp-core/src/results.rs::the_maximum_meets_the_criterion_and_the_highest_need_notcrates/udpstp-core/src/results.rs::a_sub_interval_with_nothing_received_meets_no_criterioncrates/udpstp-core/src/results.rs::no_sub_interval_meeting_the_criterion_means_no_maximum
RFC9097-6.3-2
Tested
The number of sub-intervals with duration dt MUST be set to a natural number m, so that T+I = T + m*dt with dtn+1 - dtn = dt for 1 <= n <= m.
Note: testIntTime / subIntPeriod Sub-Intervals.
Conformance Records: sub-interval-whole-trial-intervals.
Proving tests:
RFC9097-6.3-3
Tested
At least one target performance threshold (PM criterion) MUST be defined.
Note: The Performance Criterion.
Conformance Records: shallow-queue-search-alternates-at-the-bottleneck, loss-allowance-per-test-connection.
Proving tests:
RFC9097-6.3-4
Not applicable
If more than one metric and target performance threshold is defined, then the sub-interval with the maximum number of bits transmitted MUST meet all the target performance thresholds.
Note: udpstp defines one Performance Criterion, the Loss Ratio, so there is never more than one threshold to meet.
Conformance Records: shallow-queue-search-alternates-at-the-bottleneck.
RFC9097-6.3-5
Tested
Users SHALL specify the Parameter Tmax as required by each metric’s reference definition.
Note: Tmax.
Conformance Records: tmax-within-the-sub-interval.
Proving tests:
RFC9097-6.3-6
Tested
At least one target performance threshold (PM criterion) MUST be defined.
Note: Bullet restating RFC9097-6.3-3.
Proving tests:
RFC9097-6.3-7
Tested
All sub-intervals MUST be of equal duration.
Note: subIntPeriod is a whole number of Trial Intervals.
Conformance Records: sub-interval-whole-trial-intervals.
Proving tests:
RFC9097-6.3-8
Operational
The bit rate of the physical interface of the measurement systems MUST be higher than the smallest of the links on the path whose Maximum_C(T,I,PM) is to be measured (the bottleneck link).
Note: Deployment of the measurement hosts.
RFC9097-6.3-9
Tested
Measurements according to these definitions SHALL use the UDP transport layer.
Proving tests:
RFC9097-6.4-L1
Tested
The interval dtn,dtn+1 where Maximum_C(T,I,PM) occurs is the reporting sub-interval for RTD[dtn,dtn+1] and OWL[dtn,dtn+1] within RTD[T,I] and OWL[T,I].
Note: Loss and RTT are reported for the Sub-Interval of the maximum.
Proving tests:
RFC9097-6.4-1
Tested
Other metrics MAY be measured: one-way reordering, duplication, and delay variation.
Proving tests:
crates/udpstp-core/tests/delay_variation.rs::sub_intervals_collect_the_delay_samples_of_their_trial_intervalscrates/udpstp-core/tests/sub_interval_results.rs::duplicates_and_reordering_are_reported_apart_from_loss
RFC9097-6.5-1
Operational
If traffic conditioning (e.g., shaping, policing) applies along a path for which Maximum_C(T,I,PM) is to be determined, different values for dt SHOULD be picked and measurements executed during multiple intervals [T,T+I].
Note: The user picks subIntPeriod per Test.
RFC9097-6.5-2
Operational
Each duration dt SHOULD be chosen so that it is an integer multiple of increasing values k times serialization delay of a Path MTU (PMTU) at the physical interface speed where traffic conditioning is expected.
Note: The user picks subIntPeriod per Test.
RFC9097-6.6-1
Tested
The IP-Layer Capacity SHOULD be reported with at least single-Megabit resolution, in units of Megabits per second (Mbps) (which, to avoid any confusion, is 1,000,000 bits per second).
Proving tests:
RFC9097-6.6-2
Tested
The related One-Way Loss metric and Round-Trip Delay measurements for the same Singleton SHALL be reported, also with meaningful resolution for the values measured.
Proving tests:
RFC9097-6.6-3
Tested
When there are demonstrated and repeatable Capacity modes in the Sample, the Maximum IP-Layer Capacity SHALL be reported for each mode, along with the relative time from the beginning of the stream that the mode was observed to be present.
Note: Capacity Modes.
Proving tests: