Requested revision
Standard: | 802.1Qbv-2016 | Clause: | 12.29.1 & 17.2.22 & 17.7.22 |
Clause title: | The Gate Parameter Table |
Rationale for revision
The parameter AdminCycleTime as well as the interval encapsulated in the GateControlEntry cover a very large range. Especially according to the MIB definition (clause 17.7.22), the ranges are (theoretically) as following: AdminCycleTime: 1/2^32 s (approx. 0.2 ns) - 2^32/1 s (approx. 136 years) Interval: 1 ns - approx. 4.2 sec While the lower bound of the respective range is the next integer multiple of parameter tickGranularity, the upper bound may be impractical for concrete implementations. Certain domains may only require intervals and cycle times in the milliseconds range. However, by definition there is no restriction on the mentioned parameters, so implementations may be forced to reject (according to the standard) legal configurations without means to report the reason and or means to expose their characteristics/limitations beforehand. Therefore, the characteristics of an implementation shall be exposed by means of 802.1Qbv, especially when deploying a centralized configuration approach (802.1Qcc).
Proposed text
The suggestion is to introduce two additional parameters declaring characteristics of the implementation, i.e., Name Data Type Operations Conformance Supported ----------------------------------------------------------------- SupportedCycleMax RationalNumber R BE SupportedIntervalMax Integer R BE ----------------------------------------------------------------- where both characteristics shall use the same semantics as the respectively described parameter, i.e., -) SupportedCycleMax a rational number (clause 12.29.1.3) in seconds -) SupportedIntervalMax a timeIntervalValue (clause 12.29.1.2.3) Exposing these parameters support discovery of further characteristics and enable the creation of lightweight implementations for certain application domains. Consequently also the Management Information Base definitions (clause 17.7.22), as well as the upcoming YANG definitions (P802.1Qcw) shall reflect these parameters.
Impact on existing networks
None. Existing networks might or might not be checking those max values anyway.
This change just allows applications to see the limitations of the implementation and act
accordingly.
Originator
Name: | Marina Gutiérrez | Email: | marina.gutierrez@tttech.com<mailto:marina.gutierrez@tttech.com> |
Affiliation: | TTTech Computertechnik AG | ||
Submitted: | 2018-09-18 |