Patents by Inventor David C.A. Snowdon

David C.A. Snowdon has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230275680
    Abstract: A method and system for the post-adjustment (i.e., offline) of event timestamps to implement virtual time synchronization amongst detection node clocks. In existing methodologies with the goal of clock synchronization, clocks (and timestamps generated therefrom) are disciplined or adjusted at the recordation time of the events on a detection node (e.g., a switch/router, an Internet-of-Things (IoT) device, a wireless sensor, etc.). However, there is no particular reason for these clocks or timestamps to be accurate during the recordation time, but rather, should be accurate at their use or interpretation time. Further, through these recordation time adjustments, clock drifts and timing errors may be gradually introduced, leading to runaway inaccuracies. The disclosed method and system intentionally avoids the disciplining of clocks at event recordation times on the detection node and, instead, adjusts timestamps during interpretation times, to overcome the aforementioned issues.
    Type: Application
    Filed: May 9, 2023
    Publication date: August 31, 2023
    Inventors: David C.A. Snowdon, David J. Mirabito
  • Patent number: 11683111
    Abstract: A method and system for the post-adjustment (i.e., offline) of event timestamps to implement virtual time synchronization amongst detection node clocks. In existing methodologies with the goal of clock synchronization, clocks (and timestamps generated therefrom) are disciplined or adjusted at the recordation time of the events on a detection node (e.g., a switch/router, an Internet-of-Things (IoT) device, a wireless sensor, etc.). However, there is no particular reason for these clocks or timestamps to be accurate during the recordation time, but rather, should be accurate at their use or interpretation time. Further, through these recordation time adjustments, clock drifts and timing errors may be gradually introduced, leading to runaway inaccuracies. The disclosed method and system intentionally avoids the disciplining of clocks at event recordation times on the detection node and, instead, adjusts timestamps during interpretation times, to overcome the aforementioned issues.
    Type: Grant
    Filed: March 24, 2021
    Date of Patent: June 20, 2023
    Assignee: Arista Networks, Inc.
    Inventors: David C. A. Snowdon, David J. Mirabito
  • Patent number: 11483122
    Abstract: Techniques for determining a clock offset between monitoring devices in a network. Such techniques include: obtaining, by a first monitoring device, a first set of network traffic data units sent between a first endpoint and a second endpoint via a first tap on a network link between the first endpoint and second endpoint; obtaining, by a second monitoring device, a second set of network traffic data units sent between the first endpoint and the second endpoint via a second tap on the network link; calculating the clock offset between the first monitoring device and the second monitoring device using the first set of network traffic data units and the second set of network traffic data units; and performing an offset action based on the clock offset.
    Type: Grant
    Filed: August 28, 2020
    Date of Patent: October 25, 2022
    Assignee: Arista Networks, Inc.
    Inventors: David C. A. Snowdon, David J. Mirabito
  • Publication number: 20220311530
    Abstract: A method and system for the post-adjustment (i.e., offline) of event timestamps to implement virtual time synchronization amongst detection node clocks. In existing methodologies with the goal of clock synchronization, clocks (and timestamps generated therefrom) are disciplined or adjusted at the recordation time of the events on a detection node (e.g., a switch/router, an Internet-of-Things (IoT) device, a wireless sensor, etc.). However, there is no particular reason for these clocks or timestamps to be accurate during the recordation time, but rather, should be accurate at their use or interpretation time. Further, through these recordation time adjustments, clock drifts and timing errors may be gradually introduced, leading to runaway inaccuracies. The disclosed method and system intentionally avoids the disciplining of clocks at event recordation times on the detection node and, instead, adjusts timestamps during interpretation times, to overcome the aforementioned issues.
    Type: Application
    Filed: March 24, 2021
    Publication date: September 29, 2022
    Inventors: David C.A. Snowdon, David J. Mirabito
  • Publication number: 20220173884
    Abstract: Techniques described herein may be used for determining an offset between clocks in a network. Such techniques may include obtaining, by a passive time device, a first timestamp pair corresponding to a first time protocol message; obtaining, by the passive time device, a second timestamp pair corresponding to a second time protocol message; and calculating, by the passive time device, a clock offset between a time protocol master and the passive time device using the first timestamp pair, the second timestamp pair, and a pre-determined time delay constant corresponding to a network tap.
    Type: Application
    Filed: November 30, 2020
    Publication date: June 2, 2022
    Inventors: David J. Mirabito, David C.A. Snowdon
  • Patent number: 11349633
    Abstract: Techniques described herein may be used for determining an offset between clocks in a network. Such techniques may include obtaining, by a passive time device, a first timestamp pair corresponding to a first time protocol message; obtaining, by the passive time device, a second timestamp pair corresponding to a second time protocol message; and calculating, by the passive time device, a clock offset between a time protocol master and the passive time device using the first timestamp pair, the second timestamp pair, and a pre-determined time delay constant corresponding to a network tap.
    Type: Grant
    Filed: November 30, 2020
    Date of Patent: May 31, 2022
    Assignee: Arista Networks, Inc.
    Inventors: David J. Mirabito, David C. A. Snowdon
  • Publication number: 20220069970
    Abstract: Techniques for determining a clock offset between monitoring devices in a network. Such techniques include: obtaining, by a first monitoring device, a first set of network traffic data units sent between a first endpoint and a second endpoint via a first tap on a network link between the first endpoint and second endpoint; obtaining, by a second monitoring device, a second set of network traffic data units sent between the first endpoint and the second endpoint via a second tap on the network link; calculating the clock offset between the first monitoring device and the second monitoring device using the first set of network traffic data units and the second set of network traffic data units; and performing an offset action based on the clock offset.
    Type: Application
    Filed: August 28, 2020
    Publication date: March 3, 2022
    Inventors: David C.A. Snowdon, David J. Mirabito