Clock

Used to configure clock features such as PTP and Clock IWF.

CLOCK link provides the following links to configure the various clock features of the switch:


PTP

PTP (Precision Time Protocol) is defined in IEEE 1588 as Precision Clock Synchronization for Networked Measurements and Control Systems and was developed to synchronize the clocks in packet-based networks that include distributed device clocks of varying precision and stability standalone software which implements IEEE 1588. PTP is message based protocol which specifies how the real-time clocks in a distributed system synchronize with each other. PTP creates master-slave hierarchy to synchronize the clocks in the system.

To access PTP screens, go to Clock > PTP.

PTP Global Configurations

By default, the tab PTP displays the PTP Global Configurations screen.

Figure 1. PTP Global Configurations


Screen Objective This screen allows configuring the basic settings of PTP such as starting the PTP module and creating the primary context.
Navigation

Clock > PTP > Basic Settings
Fields
  • Global Status—specifies the system control status of the PTP module. The default option is Disabled. The list contains:
    • Disabled—shuts PTP in a device. This will remove all PTP related configurations from the system.
    • Enabled—starts PTP in a device. This will allow the user to configure the PTP parameters.
    Note:

    PTP module should be started for configuring the PTP parameters.

  • Network Protocol—IEEE 802.3.
Buttons
  • Apply—adds and saves new configuration.

Clock Configuration Page

Figure 2. Clock Configuration Page


Screen Objective This screen allows the user to configure the clock data set table information. The clock data set table contains information of the clock on a particular domain. The entries in this table are created with the default values.
Navigation

Clock > PTP > Clock Settings
Fields
  • PTP Profile—specifies the type of PTP Profile. The default profile is Power Profile V2. The options are:
    • No Profile
    • Default E2E
    • Default P2P
    • Utility Profile
    • Power Profile V2
  • Profile ID—1c:12:9d:00:00:00
  • Clock Mode—specifies the operating mode of the clock in the domain. The default option is Transparent. The list contains:
    • Transparent
    • Forward
  • Delay Mechanism—specifies the delay mechanism of the clock in the domain. The default option is P2P. The list contains:
    • P2P—the clock is in peer-to-peer (P2P) mode. It measures the time taken for a PTP event message to transit the device. This information will be updated in the correction field of the PTP messages.
    • E2E— the clock is in end-to-end (E2E) transparent mode. The clock calculates the residence time of PTP messages and measures the link delay of the ingress port of PTP.
  • Domain Number (0-254)—specifies the unique identifier of the domain. This domain ID defines the scope of the PTP message communication, state, operations, data sets and timescale. this value ranges from 0 to 254.
  • Domain VLAN ID (1-4094)—Specifies which VLAN that the transparent clock messages will use.
  • Domain VLAN Priority (0-7)—specifies the priority of the transparent clock messages.
  • Max Clock Ports (0-24)—specifies the number of the PTP ports. The maximum and default is 24.
  • Clock Identity—displays the unique ID of the local clock associated with the domain which is e8:e8:75:ff:fe:90:2e:02
Buttons
  • Apply—adds and saves new configuration.

PTP Interfaces

Figure 3. PTP Interfaces


Screen Objective This screen allows the user to add a PTP interface and configure the port table settings. The port settings table contains PTP configuration information for a particular port. Valid interface number and type have to be provided for configuring the port specific parameters.
Navigation

Clock > PTP > Port Settings
Fields
  • Port—the value for the context name is default. It cannot be changed.
  • Status—select the operational status of the port in PTP. The default option is Disabled. Options are:
    • Disabled—disables PTP over the interface.
    • Enabled—enables PTP over the interface.
  • Min PDelay Interval (sec)—specifies the delay interval.
  • Propagation Delay (nsec)—an estimate of the current one-way propagation delay in scaled nanoseconds on the link attached to the port, calculated using the peer delay mechanism. If the PTP port delay mechanism is end-to-end, this value will be 0.
Buttons
  • Apply—adds and saves new configuration.

Clock IWF

The Clock IWF module acts as a layer between the system clock and the protocol which synchronizes the system clock. This module selects the time source to set the system clock and maintains the information about the clock quality such as clock accuracy, class, variance, etc.

Clock Interworking Settings

Figure 4. Clock Interworking Settings


Screen Objective This screen allows the user to configure the clock IWF parameters.
Navigation

Clock > Clock IWF
Fields
  • Clock Variance—enter the variance of the primary clock. This object reflects the value provisioned by the external source (NTP/SNTP/GPS) that synchronizes the system clock. This value ranges from 0 to 255.The default value is 0 (minimum variance).
  • Clock Class—enter the class of the primary clock. This object reflects the value provisioned by the external source (NTP/SNTP/GPS) that synchronizes the system clock. This value ranges from 0 to 255. The default value is 248.
  • Clock Accuracy—enter the accuracy of the primary clock. Clock accuracy is the mean of the time or frequency error between the clock under test and a perfect reference clock, over an ensemble of measurements. This object reflects the value provisioned by the external source (NTP/SNTP/GPS) that synchronizes the system clock. This value ranges from 32 to 254. The default value is 254.
  • Clock Time Source—select the time source of the primary clock. The system clock is synchronized only through the specified source. The default option is PTP. The options are:
    • None—does not synchronize the system clock.
    • Atomic Clock—synchronizes the system clock through atomic clock.
    • GPS—synchronizes the system clock through Global Positioning System (GPS).
    • PTP—synchronizes the system clock through Precision Time Protocol (PTP).
    • NTP—synchronizes the system clock through Network Time Protocol (NTP).
    • Internal Oscillator-Synchronizes the system clock through Internal Oscillator.
  • Clock UTC Offset—enter the current UTC (Coordinated Universal Time) offset in scaled nanoseconds with respect to the system time. This value must be in the form of (+HAMM or –HH:MM) and in the range from +00:00 to +14:00 or—00:00 to—12:00. The default value is 0.
  • Hold Over Mode—select the option to specify whether the system clock is in Hold Over Mode. The default option is Enabled. The options are:
    • Enabled—enables the clock to be in holdover mode.
    • Disabled—disables the holdover mode.
Note:

The clock is said to be in Hold Over Mode if it has been previously synchronized or synchronized to another clock but is now free-running based on its own internal oscillator whose frequency is adjusted using data acquired while it had been synchronized or synchronized to the other clock.
Buttons
  • Apply—adds and saves new configuration.
Parent topic: Timing Protocols