Time Appliances Project

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Welcome to the OCP Time Appliances Project wiki.
This Project is open to the public and we welcome all those who would like to be involved.
Time is a key element to get the highest efficiency in a distributed system. The performance of a distributed system depends on the synchronization of its elements. Several industries such as telecom, mobile, power, industrial, professional audio and video and many more have embraced the need for highly accurate and more importantly reliable distribution and synchronization of time and frequency across packet networks. Although the use case scenario for each of the industries is different, they all share one common thing and that is, time synchronization. Since there is a diverse need for time synchronization across different industries, driven from different use cases and applications, managing the needs of this industry chain becomes a challenge.

Time Appliances Project (TAP) aims to provide a platform to bring together, discuss, standardize and share technologies and solutions across industries with the datacenter applications and datacenter network infrastructure as the main interest. The project aims to bring together the community of datacenter operators, application developers, and equipment and semiconductor companies together to enable datacenter time-sensitive applications such as consistency in distributed systems, edge computing, AR/VR and IoT. These applications will greatly benefit from high accuracy, reliable, and scalable distribution and synchronization of time.

IEEE 1588 Precision Timing Protocol (PTP) and other synchronization methods have been adopted by various industries to maximize the efficiency of various distributed system use cases. Each use case scenario comes with a set of requirements and configurations. These configurations are collected as a ‘PTP profile’. Time appliances project aims to support the development of a PTP profile for datacenter applications and datacenter network infrastructure. The profile will cover time-sensitive applications over OCP-compliant and PTP-aware networking infrastructure such as network switches, network clocks, network interface cards, timing modules & connectors, etc. Additionally, the profile will address various requirements for high accuracy and reliable distribution and synchronization of time, such as expected performance, networking, software API, data models, deployment and telemetry. The project also aims at openness and interoperability through the use of open-source PTP software implementations for timing appliances.

Datacenter applications are the primary target of time appliances project. In addition, the project extends to related topics on time synchronization in academia, research and other industries. The time appliances project brings together the community and will be highly collaborative through technical meetings and collaboration with other OCP Projects including the Networking, Storage, Server, and Telco Projects.

Disclaimer: Please do not submit any confidential information to the Project Community. All presentation materials, proposals, meeting minutes and/or supporting documents are published by OCP and are open to the public in accordance to OCP's Bylaws and IP Policy. This can be found on the OCP OCP Policies page. If you have any questions please contact OCP.

Mission Statement

1. Create specifications and references for Data Center Timing appliances, applications and networking infrastructure
2. Promote openness in Timing Appliances and interfaces through open-source implementations

Project Leadership


Ahmad Byagowi, Ph.D. (OCPTAP/Facebook)

IC Rep:

Elad Wind (OCP/NVIDIA)


Project Objective POC Meeting Schedule
#1 Open Source Grandmaster Development of an open source grandmaster for DC and Edge systems Oleg Obleukhov &
Dotan Levi
discussed during project calls
#2 Data Center PTP Profile Development of a PTP Profile tailored for data center applications Michel Ouellette
#3 Precision Time API Time APIs to disseminate the time error (error bound) and bring accurate time to the user space Georgi Chalakov
#4 Oscillators Classification and measuring of oscillators Gary Giust
Overall Project meeting coordinator Kelvin Chukwu please send all inquiries to Kelvin

Get Involved

- TAP Mailing List
- OCP Projects Calendar


- Charter
- OCP Presentation Template - please contact Michael Schill or Archna Haylock for a copy

Release Candidates (RC) Docs

Worstream Name Format Version Date
#1 Open Source Grandmaster MD v0.2 March 31, 2021
#2 Data Center PTP Profile PDF v0.3 April 7, 2021

TAP GitHub

- Github Repo

TAP Google Drive

- Google Drive Document Repository

Regular Project Calls

- Wednesdays at 11am PST, starting on July 15th, 2020. Repeats every 2 weeks following that
- Please contact Kelvin Chukwu to propose any agenda items

Join the meeting from your computer, tablet or smartphone:


Dial in:

United States (Toll Free): +1 877 309 2073                                        
United States:             +1 571 317-3129                                        
Access Code:                565-185-493

Upcoming Calls

Date Topics Speakers
#27 Jul-28, 2021 Sundial: Fault-tolerant Clock Synchronization for Datacenters Gautam Kumar & Yuliang Li, Ph.D.
#26 Jul-14, 2021 Elad Blatt
#25 Jun-30, 2021 GNSS Anti-Jamming and Spoof Mitigation Charlie Ferreira
#24 Jun-16, 2021 An Introduction to IEEE1588-2019 Doug Arnold, Ph.D.

Recordings from Past Calls

Date Topics Speakers Slides
#23 Jun-02, 2021 Introduction to MAC and CSACs Robert Lutwak, Ph.D. Slides
#22 May-19, 2021 Open Synchronization implementations on Linux/k8s Clusters Timo Jokiaho & Pasi Vaananen Slides
#21 May-5, 2021 White Rabbit: An Accurate Time and Frequency Transfer over Ethernet Maciej Lipinski, Ph.D. Slides
#20 Apr-21, 2021 Time Scale Ensembles in Uncertain Environments Marc A. Weiss, Ph.D. Slides
#19 Apr-7, 2021 Clock and Oscillator Statistics and Characterization Techniques Slides
#18 Mar-24, 2021 Introduction to Project Corundum for Time services Alex Forencich, Ph.D. Slides
#17 Mar-10, 2021 Oscillators Classification, Workstream #4 goals and kickoff Gary Giust, Ph.D. Slides
#16 Feb-24, 2021 GNSS Timing Samuli Pietila
#15 Feb-10, 2021 Centralized GNSS Monitoring and Assurance Nir Laufer Slides
#14 Jan-27, 2021 Huygens and its Applications Balaji Prabhakar, Ph.D.
#13 Jan-13, 2021 TAP 2020 Recap, 2021 Plans Ahmad Byagowi, Ph.D. Slides
#12 Dec-16, 2020 Chip Scaled Atomic Clocks John Kitching, Ph.D. Slides
#11 Dec-2, 2020 Data Center PTP Profile, Workstream #2 proposal Michel Ouellette
#10 Nov-18, 2020 Computer Timekeeping and Synchronization Kevin Stanton, Ph.D. Slides
#9 Nov-4, 2020 Time Sync in TSNs (History of TSN, IEEE 802.1AS Overview) Hesham ElBakoury Slides
#8 Oct-21, 2020 Starter's guide to ptp4l Maciej Machnikowski Slides
#7 Oct-7, 2020 Timing card implementation Ahmad Byagowi, Ph.D.
#6 Sep-23, 2020 Practical Use Cases of Synchronized Clocks Georgi Chalakov
#5 Sep-9, 2020 Data Center PTP Profile, Workstream #2 goals and draft spec Michel Ouellette
#4 Aug-26, 2020 Open Grandmaster, Workstream #1 goals and draft spec Oleg Obleukhov
#3 Aug-12, 2020 TAP Vision as well as the impact of precision oscillator noise on PTP time error Dotan Levi
#2 Jul-29, 2020 Detailed Project Proposal and Discussion Michel Ouellette
#1 Jul-15, 2020 Proposal to launch OCP-TAP Incubation Project Ahmad Byagowi, Ph.D. Slides

Presentations & Videos

- OCP TAP - Vision
- TAP Presentation
- GTC 2021: Time Synchronization in Distributed Data Centers Video Slides
- Impact of Oscillator Noise on PTP Time Error – Part 1
- Impact of Oscillator Noise on PTP Time Error – Part 2
- ELPROMA TAP Remarks Oct 7 2020

Recordings from Workstream Calls

Workstream Date Meeting Slides
#4 Oscillators Jun-2 2021 Recording
May-26 2021 Recording
May-19 2021 Recording
May-12 2021 Recording
May-5 2021 Recording
Apr-28, 2021 Recording
Apr-21, 2021 Recording
Apr-14, 2021 Recording
Apr-7, 2021 Recording
Mar-31, 2021 Recording
Mar-18, 2021 Recording Slides

References & External Links

- Spanner, TrueTime & The CAP Theorem by Eric Brewer, Google
- [ Sundial: Fault-tolerant Clock Synchronization for Datacenters] by Google Inc. and Harvard University
- Practical Uses of Synchronized Clocks in Distributed Systems by Barbara Liskov
- Stanford Paper for reference only
- Spanner Paper for reference only
- On Time Synchronization Issues in Time-Sensitive Networks with Regulators and Nonideal Clocks for reference only, raised by Elad
- Accurate Network Clock Synchronization at Scale for reference only, raised by Hesham
- Exploiting a Natural Network Effect for Scalable, Fine-grained Clock Synchronization for reference only, raised by Hesham
- SIMON: A Simple and Scalable Method for Sensing, Inference and Measurement in Data Center Networks for reference only, raised by Hesham
- New Guidelines for Inclusiveness for reference only, raised by Michael