P802.1ASdm – Hot Standby

This amendment specifies protocols, procedures, and managed objects for hot standby without use of the Best Master Clock Algorithm (BMCA), for time-aware systems, including:

  • A function that transforms the synchronized times of two generalized Precision Time Protocol (gPTP) domains into one synchronized time for use by applications;
  • A function that directs the synchronized time of one gPTP domain into a different gPTP domain; and
  • Mechanisms that determine whether a gPTP domain has sufficient quality to be used for hot standby.

This amendment also addresses errors and omissions in the description of existing functionality.

Current Status

Status Task Group ballot
Current Draft D0.3 (1 Sep 2021)
PAR & CSD Full title: Draft Standard for Local and Metropolitan Area Networks: Timing and Synchronization for Time-Sensitive Applications — Amendment: Hot Standby
PAR (Approved: 03 Jun 2020; Expires: 31 Dec 2024)
Editor Geoffrey Garner
Web page Craig Gunther


Date Document
13 Dec 2021 P802.1ASdm, Draft 0.3 TG comment disposition
01 Sep 2021 P802.1ASdm, Draft 0.3
09 Aug 2021 P802.1ASdm, Draft 0.2 TG comment disposition
15 Mar 2021 P802.1ASdm, Draft 0.2 (with line numbers)

The above list includes only the latest version of (proposed) dispositions. See the project folder for a complete list). The dates listed are the website file dates; they may differ from the creation dates in the documents.


Important NOTICE on contributions.

As assembled by the editor. Notify the editor of an errors or omissions. This list may omit documents superseded by later versions. For the full list of contributions, see filenames beginning “dm-” in the 2020, 2021 and 2022 802.1 public directories. The dates listed are the website file dates and often differ from creation dates in the documents.
DateDocument IDTitleAuthor
2021-11-15dm-turner-ASredundancy-1121-v01.pdfIEEE802.1ASdm - RedundancyMax Turner
2021-09-15dm-turner-text-contribution-0921-v01.pdfContribution towards P802.1ASdm/D0.3 Comment resolutionMax Turner
2021-08-09asdm-garner-discussion-of-maint-items-331-332-0821-v02.pdfDiscussion of Maintenance Items 331 and 332 - Revision 2Geoffrey Garner
2021-06-21dm-Lv-Rodrigues-comment-84-against-d0-2-0621-v00.pdfComment #84 of IEEE Draft P802.1ASdm/D0.2Jingfei Lv, Silvana Rodrigues
2020-11-02dm-garner-plans-1120-v00.pdfInitial Plans and Assumptions for 802.1ASdmGeoffrey Garner
2020-03-09dm-cummings-as-4-domains-0320-v04.pdf802.1AS Hot Standby Amendment: 4 DomainsRodney Cummings
2020-02-18dm-potts-as-hot-standby-multiple-domains-0220-v01.pdfIEEE 802.1AS-2020 Addendum for “Hot-Standby” with multiple domain definitionMichael Potts
2020-01-16new-cummings-as-hot-standby-scope-0120-v02.pdf802.1AS Hot Standby Amendment: Scope DiscussionRodney Cummings

The above list includes only the latest version of updated documents and omits those superseded by subsequent discussion or inclusion in the current draft (see filenames beginning “dm-” in the 2020 or 2021 public directories for a complete list). The dates listed are the website file dates; they may differ from the creation dates in the documents.

Please contact Craig Gunther if you have comments to this page.