Requested revision
| Standard: | IEEE Std 802.1AS-2020 | Clause: | 10.3.17.3, 10.3.18.3, 10.4.3.3 |
| Clause title: | State diagram | ||
Rationale for revision
In the SET_INTERVALS state of the AnnounceIntervalSetting state machine (Figure 10-19), the statement “if (announceInterval < oldAnnounce) causes the variable announceSlowdown to be set to TRUE if the condition is TRUE (i.e., if announceInterval is less then oldAnnounceInterval), and FALSE otherwise. However, announceSlowdown being set to TRUE means that announceInterval has increased, not decreased. The condition should be “if (announceInterval > oldAnnounceInterval)”. Similar changes are needed in the SyncIntervalSetting state machine (Figure 10-20), i.e., change “if (syncInterval < oldSyncInterval)” to “if (syncInterval > oldSyncInterval), and in the GptpCapableIntervalSetting state machine (Figure 10-23), i.e., change “if (gPtpCapableMessageInterval < oldgGptpCapableMessageInterval)” to “if (gPtpCapableMessageInterval > oldgGptpCapableMessageInterval)”. In addition, the final sentence of the definition of the per-port global variable announceSlowdown (10.3.10.2), which currently reads “When announceSlowdown is set to FALSE, the PortAnnounceTransmit state machine immediately sends Announce messages at the new (i.e., slower) rate.” Is not correct, as when announceSlowdown is FALSE the new rate is faster or the same as the old rate, not slower. Similar changes are needed for syncSlowdown (10.2.5.17) and gPtpCapableMessageSlowdown (10.2.5.19).
Proposed text
In the SET_INTERVALS state of the AnnounceIntervalSetting state machine (Figure 10-19), change the statement “if (announceInterval < oldAnnounceInterval)” to “if (announceInterval > oldAnnounceInterval)”. In the SET_INTERVAL state of the SyncIntervalSetting state machine (Figure 10-20), change the statement “if (syncInterval < oldsyncInterval)” to “if (syncInterval > oldsyncInterval)”. In the SET_INTERVAL state of the GptpCapableIntervalSetting state machine (Figure 10-23), change the statement “if (gPtpCapableMessageInterval < oldGptpCapableMessageInterval)” to “if (gPtpCapableMessageInterval > oldGptpCapableMessageInterval)”. In the last sentence of 10.3.10.2, before the NOTE, change the parenthetic expression “(i.e., slower)” to “(i.e., faster or the same)”. In the last sentence of 10.2.5.17, before the NOTE, change the parenthetic expression “(i.e., slower)” to “(i.e., faster or the same)”. In the last sentence of 10.2.5.19, before the NOTE, change the parenthetic expression “(i.e., slower)” to “(i.e., faster or the same)”.
Impact on existing networks
This change corrects an error. Assuming that implementers have implemented these features correctly (i.e., an implementer realizes the error and makes the correction), there is no impact on existing networks.
Originator
| Name: | Geoffrey M. Garner | Email: | gmgarner@alum.mit.edu <mailto:gmgarner@alum.mit.edu> |
| Affiliation: | Huawei (Consultant) | ||
| Submitted: | 2020-10-29 | ||