Timing synchronization service and distribution system

Patent metadata

Field	Value
Publication number	US-11115142-B1
Application number	US-201916438310-A
Country	US
Kind code	B1
Filing date	Jun 11, 2019
Priority date	Dec 21, 2018
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

This disclosure describes techniques for delivering high-accuracy and high-precision clock synchronization in heterogeneous distributed computer clusters. For example, the disclosure describes a synchronization engine that sets efficient clock synchronization processes based on a cluster node's characteristics, pricing, precision, geolocation, and/or cluster topology, while in some cases using a combination of master clock data with internal atomic clocks of computers. The techniques described herein integrate the synchronization engine into a time synchronization process that may provide stability, versatility, precision and cost balance using technical improvements for characterizing timing system delivery channels.

First claim

What is claimed is:

1. A method comprising:
sending, by a first probing device in a network comprising a plurality of probing devices, and to a second probing device of the plurality of probing devices in the network, a timestamp for the first probing device, wherein the first probing device and the second probing device are included in a probing device pair;
receiving, by the first probing device, and from the second probing device, a timestamp for the second probing device;
determining, by the first probing device, a timestamp offset between the timestamp for the first probing device and the timestamp for the second probing device;
receiving, by the first probing device, an independent timestamp offset for the probing device pair;
when the timestamp offset is classified as a valid timestamp offset based on a difference between the timestamp offset and the independent timestamp offset for the probing device pair, determining, by the first probing device, based at least in part on the timestamp for the first probing device and the timestamp for the second probing device, an upper-bound delta time and a lower-bound delta time for the probing device pair;
calculating, by the first probing device, and based at least in part on the upper-bound delta time and the lower-bound delta time for the probing device pair, a slope value and an intercept value for the first probing device; and
sending, by the first probing device, and to a local system master clock, the slope value and the intercept value for the first probing device.

2. The method of claim 1 , further comprising:
comparing, by the first probing device, the timestamp offset and the independent timestamp offset; and
responsive to determining that the timestamp offset is approximately equal to the independent timestamp offset, classifying, by the first probing device, the timestamp offset as a valid timestamp offset.

3. The method of claim 1 , further comprising:
sending, by the first probing device, and to the second probing device of the plurality of probing devices in the network, a second timestamp for the first probing device;
receiving, by the first probing device, and from the second probing device, a second timestamp for the second probing device;
determining, by the first probing device, a second timestamp offset between the second timestamp for the first probing device and the second timestamp for the second probing device;
comparing, by the first probing device, the second timestamp offset and the independent timestamp offset;
responsive to determining that the second timestamp offset is not approximately equal to the independent timestamp offset, classifying, by the first probing device, second the timestamp offset as an invalid timestamp offset; and
responsive to classifying the second timestamp offset as an invalid timestamp offset, refraining, by the first probing device, from determining a second upper-bound delta time and a second lower-bound delta time for the probing device pair based on the second timestamp offset.

4. The method of claim 1 , further comprising:
sending, by the first probing device, and to the second probing device of the plurality of probing devices in the network, a second timestamp for the first probing device;
receiving, by the first probing device, and from the second probing device, a second timestamp for the second probing device;
determining, by the first probing device, based at least in part on the timestamp for the first probing device, the timestamp for the second probing device, the second timestamp for the first probing device, and the second timestamp for the second probing device, the upper-bound delta time and the lower-bound delta time for the probing device pair;
calculating, by the first probing device, and based at least in part on the upper-bound delta time and the lower-bound delta time for the probing device pair, the slope value and the intercept value for the first probing device; and
sending, by the first probing device, and to the local system master clock, the slope value and the intercept value for the first probing device.

5. The method of claim 4 , further comprising:
sending, by the first probing device, and to the second probing device of the plurality of probing devices in the network, a third timestamp for the first probing device;
receiving, by the first probing device, and from the second probing device, a third timestamp for the second probing device;
determining, by the first probing device, and based at least in part on the third timestamp for the first probing device, the third timestamp for the second probing device, the upper-bound delta time for the probing device pair, and the lower-bound delta time for the probing device pair, an updated upper-bound delta time and an updated lower-bound delta time for the probing device pair;
calculating, by the first probing device, and based at least in part on the updated upper-bound delta time and the updated lower-bound delta time for the probing device pair, an updated slope value and an updated intercept value for the first probing device; and
sending, by the first probing device, and to the local system master clock, the updated slope value and the updated intercept value for the first probing device.

6. The method of claim 1 , further comprising:
receiving, by the first probing device, and from the local system master clock, a reference clock probe that includes a time synchronization offset for the first probing device; and
synchronizing, by the first probing device, and based at least in part on the time synchronization offset, a clock on the first probing device.

7. The method of claim 1 , wherein sending the timestamp for the first probing device comprises:
sending, by the first probing device, and to the second probing device, a probe packet that includes the timestamp for the first probing device.

8. The method of claim 1 , wherein calculating the slope value and the intercept value for the first probing device comprises:
creating, by the first probing device, a non-linear model; and
calculating, by the first probing device, and using the non-linear model, the upper-bound delta time, and the lower-bound delta time, the slope value and the intercept value for the first probing device.

9. The method of claim 1 , further comprising:
sending, by the first probing device, and to a third probing device of the plurality of probing devices in the network, a second timestamp for the first probing device, wherein the first probing device and the third probing device are included in a second probing device pair;
receiving, by the first probing device, and from the third probing device, a timestamp for the third probing device;
determining, by the first probing device, based at least in part on the second timestamp for the first probing device and the timestamp for the third probing device, an upper-bound delta time and a lower-bound delta time for the second probing device pair;
calculating, by the first probing device, and based at least in part on the upper-bound delta time and the lower-bound delta time for the probing device pair and the upper-bound delta time and the lower-bound delta time for the second probing device pair, the slope value and the intercept value for the first probing device.

10. A first probing device comprising:
one or more processors operably coupled to a memory; and
a synchronization engine executable by the one or more processors to:
send, to a second probing device of a plurality of probing devices in a network, a timestamp for the first probing device, wherein the first probing device and the second probing device are included in a probing device pair;
receive, from the

Assignees

• Equinix Inc

Inventors

• Ozarkar Anand
• Sharma Ankur
• Anderson Christopher Alan
• Li Danjue
• Weaver Lance
• Lillie Brian J

Classifications

• H04L43/12

  Network monitoring probes · CPC title

• H04L43/106

  using time related information in packets, e.g. by adding timestamps · CPC title

• H04L43/0847

  Transmission error · CPC title

• H04L69/26

  Special purpose or proprietary protocols or architectures (network applications for proprietary or special purpose networking environments H04L67/12) · CPC title

• H04J3/14

  Monitoring arrangements {(for SDH/SONET rings H04J3/085)} · CPC title