Configuring the Time Synchronization Connectors and the Time Synchronization Time and Frequency Reference Priorities

Time-Stamping and Time Synchronization

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Intel® PAC
Napatech SmartNIC
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User Guide

In this section

This section describes how to configure the time synchronization connectors and how to prioritize time synchronization time and frequency references.

Note: SyncE does not apply to NT200A02 and NT200A01 SmartNICs.

Time synchronization connectors

The TimeSyncConnectorExt1, TimeSyncConnectorInt1 and TimeSyncConnectorInt2 parameters configure usage (input, output or repeat) and mode (NT-TS or PPS) of the external SMA time synchronization connector/port, internal time synchronization connector 1 and internal time synchronization connector 2, respectively.
Note: The Ext1 port is the external SMA time synchronization connector, on the NT200A02 and NT200A01 SmartNICs, or, on other SmartNICs, the SMA port on the external time synchronization connector.
Note: If one connector is specified, all three connectors as well as the time synchronization time reference priority list (see Time synchronization time reference priority list) must be specified.

The usage and mode of the connector(s) can be specified as:

  • No usage ('None')
  • Input connector in NT-TS time synchronization mode ('NttsIn')
    Note: Only one NttsIn connector can be specified.
    Note: NttsIn cannot be specified for the Ext1 port.
  • Input connector in PPS time synchronization mode ('PpsIn')
  • Output connector with an NT-TS signal generated if the SmartNIC is working as time synchronization master ('NttsOut')
    Note: NttsOut cannot be specified for the Ext1 port.
  • Output connector with a PPS signal generated from the SmartNIC clock ('PpsOut')
  • Repeat connector repeating the signal received on the Ext1 port ('RepeatExt1' – only applies to the internal time synchronization connectors, and only if TimeSyncConnectorExt1 is set to 'PpsIn')
  • Repeat connector repeating the signal received on internal time synchronization connector 1 ('RepeatInt1' – only applies to the Ext1 port and to internal time synchronization connector 2, and only if TimeSyncConnectorInt1 is set to 'PpsIn' or, for internal time synchronization connector 2, 'NttsIn')
  • Repeat connector repeating the signal received on internal time synchronization connector 2 ('RepeatInt2' – only applies to the Ext1 port and to internal time synchronization connector 1, and only if TimeSyncConnectorInt2 is set to 'PpsIn' or, for internal time synchronization connector 1, 'NttsIn')

Time synchronization time reference priority list

The TimeSyncReferencePriority parameter specifies a priority list for the clock references when more than one reference is used. The reference with the highest priority is listed first. The list defines the failover and fallback sequence in case of failure and reconnection.

The references that can be included in the list are:

  • One of the time synchronization connectors ('Ext1', 'Int1' or 'Int2')
  • PTP slave mode ('PTP')
  • OS time ('OSTime') or the free-running SmartNIC clock ('FreeRun')

Zero or one time synchronization connector must be specified in the list.

Zero or one PTP slave mode must be specified.

Either OS time or the free-running SmartNIC clock must be specified in the list at the last position, since these references cannot fail.

Note: When a clock reference is not included in the priority list, it is disabled.

Time synchronization frequency reference priority

The TimeSyncFrequencyReferencePriority parameter specifies a priority list for the base frequency reference for the time stamp clock.

The references that can be included in the list are:

  • SyncE ('SyncE')
  • The free-running SmartNIC clock ('FreeRun')

The free-running SmartNIC clock must be specified in the list at the last position, since this reference cannot fail.

If SyncE is not supported by the network, configure SmartNICs to permanently use the local oscillator by using the value FreeRun.

Illustration of time synchronization priority and failover

This figure shows how the time stamp clock of a SmartNIC is controlled by a base frequency and a time reference.

Control of SmartNIC time stamp clock by base frequency and time reference

ntservice.ini code lines

The syntax for the ntservice.ini code lines configuring the time synchronization connectors, prioritizing time synchronization clock references and specifying the time synchronization frequency reference is:

'TimeSyncConnectorExt1' '=' ( 'None' | 'PpsIn' |
 'PpsOut' | 'RepeatInt1' | 'RepeatInt2' )
'TimeSyncConnectorInt1' '=' ( 'None' | 'NttsIn' | 'PpsIn' |
 'NttsOut' | 'PpsOut' | 'RepeatInt1' | 'RepeatInt2' )
'TimeSyncConnectorInt2' '=' ( 'None' | 'NttsIn' | 'PpsIn' |
 'NttsOut' | 'PpsOut' | 'RepeatInt1' | 'RepeatInt2' )
'TimeSyncReferencePriority' '=' [ ( ( 'Ext1' | 'Int1' | 'Int2' ) |
 'PTP' ) ',' ] [ ( 'PTP' | ( 'Ext1' | 'Int1' | 'Int2' ) ) ',' ]
 ( 'OSTime' | 'FreeRun' )
'TimeSyncFrequencyReferencePriority' '=' [ SyncE ',' ] 'FreeRun'

Example:

TimeSyncConnectorInt1=NttsIn
TimeSyncConnectorExt1=PpsOut
TimeSyncReferencePriority=Int1,FreeRun
TimeSyncFrequencyReferencePriority=SyncE,FreeRun

Default values

This table shows the default values.

Parameter Default Value
TimeSyncConnectorExt1 PpsIn
TimeSyncConnectorInt1 None
TimeSyncConnector-Int2 None
TimeSyncReferencePriority Ext1,FreeRun
TimeSyncFrequencyReferencePriority FreeRun