Setting Date and Time Automatically using PTP

  • Updated on Aug 7, 2024
  • Published on Dec 15, 2021
  • 9 minute(s) read
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Precision Time Protocol (PTP), offers an advanced method of synchronisation in Ethernet networks. Users can enable this synchronisation to achieve maximum scalability in the network infrastructure.

PTP boundary clock enables users to configure a clock with multiple PTP ports in a domain and maintains the timescale used in the domain. It can serve as the main source of time, for example, the master clock and can also synchronise to another clock, such as a slave clock.

Note: PTP Boundary Clock is only available on LX-SyncE only.

To update the date and time automatically using PTP

  1. Access the page System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration

PTP Settings

Parameter Description
Clock Enable Enables the PTP Precision Time Protocol clock synchronisation module.
Inbound criterion Max threshold for synchronisation to declare synchronisation state. Available options are 1 microsecond, 100 microseconds or class-b

Note: The class-b option is available only for platforms (e.g: LX-SyncE) that support Class-B compliant (See ITU-T G.8273.2)
Inbound status Current state of the synchronisation error. (Expressed in nanoseconds)
Synchronisation status The status of the synchronisation.

Clock parameters

Parameter Description
Class An attribute defining a clock’s TAI traceability

Acceptable values range from 0 to 254.
Prio 1 A user configurable designation, where the clock belongs to an ordered set of clocks from which a master is selected.

Acceptable values range from 0 to 255
Prio 2 A user configurable designation, which provides finer grained ordering among otherwise equivalent clocks.

Acceptable values range from 0 to 255
PTP Profile Default PTP profiles set by the administrator.

PTP (IEEE1588-2008) introduced Profile, permitting a liberty on prerequisites, parameters, and algorithm to handle the synchronisation.

Supported profiles:

  • PTP Default Profile: Precision time protocol telecom profile for frequency and phase/time synchronisation, which supports L2 Multicast with Slave mode only.
  • PTP Telecom Profile (ITU-T G.8265.1): Precision time protocol telecom profile for frequency synchronisation, which supports L3 Unicast with Slave Mode only. This Telecom Profile is backward compatible with Accedian legacy PTP feature.
  • PTP Telecom Profile (ITU-T G.8275.1): Precision time protocol telecom profile for phase/time synchronisation with full timing support from the network. Supports L2 Multicast for both Ordinary Clock (Master Clock, Slave Clock) and Boundary Clock with Class-B compliant.
Layer-2 PTP port list List of PTP ports for Default profile and PTP Telelcom ITU-T G.8275.1 profile.
Layer-3 PTP port list List of PTP ports for PTP Telelcom ITU-T G.8265.1 profile.

Configuring PTP Port Settings
To create a new PTP port for the selected profile

  1. Access the page System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration.

  2. Click Add under the Layer-2 or Layer-3 PTP port list.

  3. Click Apply.

To delete a PTP port for the selected profile

  1. Access the page System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration.

  2. Click on the PTP port.

  3. Click Delete.

To edit a PTP port for the selected profile

  1. Access the page System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration.

  2. Click on the PTP port.

  3. Click Apply.

PTP Settings (System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration)

To add a Layer-3 PTP port

  1. From System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration.

  2. Select the Telecome Profile (ITU-T G.8265.1) in the PTP settings dialog.

  3. Click Add , under Layer-3 PTP port list, and the Layer-3PTP port settings dialog will open.

Parameter Description
PTP port name Name of the PTP port.
Time to Live The Time To Live (TTL) is the limit on the number of hops a packet is allowed before it is dropped.

Range: 1-255

Priority Settings

Parameter Description
DiffServ Code Point When using PTP, the priority can be set in the Differentiated Services Code Point by making a selection in the drop-down list.

Range: 0-63.

When using PTP, the priority of the VLAN frames can be set in the VLAN priority bits if the link is through a VLAN.

Range: 0-7

Message Frequencies

Parameter Description
Sync Interval Specifies the interval of Sync messages.

Possible values are:

  • -4: 16 messages/ second
  • -3: 8 messages/ second
  • -2: 4 messages/second
  • -1: 2 messages/second
  • 0: 1 message/second
  • 1: 1 message/2 seconds
  • 2: 1 message/4 seconds
  • 3: 1 message/8 seconds
Announce Interval Specifies the interval of Announce messages.

Possible values are:

  • -3: 8 messages/ second
  • -2: 4 messages/ second
  • -1: 2 messages/second
  • 0: 1 message/second
  • 1: 1 message/2 seconds
  • 2: 1 message/4 seconds
  • 3: 1 message/8 seconds
Default value: 1: 1 message/2 seconds
Announce Receipt Timeout Specifies the number of Announce messages that can be lost before a timeout occurs. Range 2-10

Unicast configuration

Parameter Description
Unicast Renew Interval Interval between request of Announce/Sync/Delay Response interval; expressed in seconds Acceptable values range from 60 to 1000.
Port mode The PTP port mode. Specifies the state of PTP port.

Possible values:

  • Force-master: Forced to Master state.
  • Force-slave: Forced to Slave state.
  • Auto: The state of PTP port is determined by the Best Master Clock Algorithm.

Telecom Slave Configuration

Parameter Description
Sync Receipt Timeout Specifies the number of Sync messages that can be lost before a timeout occurs. Range 2-10.
Delay Response Receipt Timeout Specifies the number of Delay Response messages that can be lost before a timeout occurs. Range 2-10.

To add a Layer-2 PTP port

  1. From System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration.

  2. Select the Default profile (IEEE1588-2008) or the Telecome profile (ITU-T G.8275.1) in the PTP settings dialog.

  3. Click Add , under Layer-2 PTP port list, and the Layer-2 PTP port settings dialog will open.

Parameter Description
PTP port name Name of the PTP port.
Interface name A name to identify the interface. Indicates the interface used to exchange the PTP messages.
Multicast address The layer-2 multicast destination address. Both the non-forwardable multicast address 01-80-C2-00-00-0E and the forwardable multicast address 01-1B-19-00-00-00 are supported.
Domain The domain number.

Range 0-255.
Port mode The PTP port mode. Specifies the state of PTP port.

Possible values:

  • Force-master: Forced to Master state.
  • Force-slave: Forced to Slave state.
  • Auto: The state of PTP port is determined by the Best Master Clock Algorithm.

Priority Settings

Parameter Description
Priority Code Point When using PTP, the priority of the VLAN frames can be set in the VLAN priority bits if the link is through a VLAN.

Range: 0-7

Message frequencies

Parameter Description
Sync Interval Specifies the interval of Sync messages

Possible values are:

  • -4: 16 messages/ second
  • -3: 8 messages/ second
  • -2: 4 messages/ second
  • -1: 2 messages/ second
  • 0: 1 message/ second
  • 1: 1 message/2 seconds
  • 2: 1 message/4 seconds
  • 3: 1 message/8 seconds
Delay Request Offset Specifies delay request offset based on the sync interval.

Range: 0-5.
Announce Interval Specifies the interval of Announce messages.

Possible values are:

  • -3: 8 messages/ second
  • -2: 4 messages/ second
  • -1: 2 messages/ second
  • 0: 1 message/ second
  • 1: 1 message/2 seconds
  • 2: 1 message/4 seconds
  • 3: 1 message/8 seconds
Default value: 1: 1 message/2 seconds
Announce Receipt Timeout Number of Announce messages not received before a timeout is triggered.

Range 2-10.

Telecome Profile Configuration

Parameter Description
Default priority The localPriority is assigned to a PTP port. This attribute is used when configuring the PTP port in the Telecom Profile ITU-T G.8275.1.

Range: 1-255

Viewing Summary of PTP Port Statistics

To view the summary of PTP port statistics

  1. Access the page System â–¶ Configuration â–¶ Time â–¶ PTP â–¶ Statistics .
    A dialog appears with the statistics.

PTP Statistics (System â–¶Configuration â–¶Time â–¶PTP â–¶Statistics)

Parameter Description
Index Index assigned to the PTP port.
PTP port name Name of the PTP port.
Last mean path delay The last known value that PTP frames take to travel between the master and slave.
Last offset adjustment The last offset adjustment for the PTP port.
Nbr of synchronisation Number of PTP port synchronisations.
Nbr of correction Number of PTP port corrections

To view PTP port statistics

  1. From System â–¶Configuration â–¶Time â–¶PTP â–¶Statistics.
  2. Click on the PTP Port you wish to view, a dialog opens with the PTP port statistics.

PTP Port Statistics (System â–¶Configuration â–¶Time â–¶PTP â–¶Statistics)

Parameter Description
PTP version The PTP version number supported on the unit.
Port mode The PTP port mode.
Port state The state of the PTP port.
Clock ID Identifies the clock
Port ID Identifies the port

Unicast Negociation Mechanism Message counters

Parameter Description
T1 The last value of T1 timestamp
T2 The last value of T2 timestamp
T3 The last value of T3 timestamp
T4 The last value of T4 timestamp
Last corr. field The last value of correction field
Master Id Identifies the current master clock
Master address The address of the current master clock
Class PTP clock class of the current master clock. An attribute defining a clock’s TAI traceability

Note: When advertising a new clock class in SyncE and PTP a trap will now be generated and provide the new clock class
Prio 1 Priority 1 of the current master clock. A user configurable designation, where the clock belongs to an ordered set of clocks from which a master is selected.
Prio 2 Priority 2 of the current master clock. A user configurable designation, which provides finer grained ordering among otherwise equivalent clocks.
Accuracy Accuracy of the current clock
Variance Stability of the current clock
Steps removed Number of communication paths traversed between the local clock and the grandmaster clock
Time source Time source of PTP, it may be internal or a source external to PTP
Grandmaster Id Identifies the grandmaster

General Message counters

Parameter Description
Announce Number of Announce messages received or transmitted.
Sync cell
Follow-up Number of Announce messages received or transmitted.
Delay Request Number of Follow-up messages received or transmitted.
Delay Response Number of Delay Request messages received or transmitted.
Rx Rx values for:
  • Announce
  • Follow-up
  • Sync
  • Delay Request
  • Delay Response
Tx Tx values for:
  • Announce
  • Follow-up
  • Sync
  • Delay Request
  • Delay Response
Request Number of Announce, Sync, Delay Response messages requested
Grant Number of Announce, Sync, Delay Response messages granted
Cancel Number of Announce, Sync, Delay Response messages cancelled
AckCancel Number of Announce, Sync, Delay Response messages ackCancelled

Configuring the PTP Grantor for the PTP Port

To configure the PTP Grantor

  1. Access the page System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration.

  2. Click on the PTP port you wish to configure from the Layer-3 PTP port list.

  3. Click the Add button below the Unicast PTP Grantor list.

  4. Select the values you wish to configure for the PTP grantor..

  5. Click Apply.

To delete a PTP Grantor instance

  1. Access the page System â–¶Configuration â–¶Time â–¶PTP â–¶Configuration.

  2. Select the PTP port in the Layer-3 PTP port list by clicking its name.

  3. Select the PTP grantor instance in the Unicast PTP Grantor list by clicking its name.

  4. Click Delete.

Note: To access the Unicast options, you must select the Telecom Profile (ITU-T G.8265.1) radio button in the PTP Profile settings.
Users can only configure a PTP grantor when working on profile ITU-T G.8265.1.

PTP Grantor configuration for the PTP Port (System â–¶Configuration â–¶Time â–¶PTP â–¶
Configuration)

Parameter Description
PTP Grantor name Name of the PTP grantor.
Interface name Name of the interface used to communicate with the PTP master.
Hostname / Address Name or Address of the PTP master.
Domain The domain number.

Range: 0-255
Priority The priority of PTP master.

Acceptable values: 0 (disabled), 1 (best) and 2 (worst).

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