Configuring the PTP Clock

Time-Stamping and Time Synchronization
Platform
Napatech SmartNIC
Content Type
User Guide
Capture Software Version
Link™ Capture Software 12.2

In this section

This section describes how to configure the PTP clock.

PTP clock priorities

The PtpClockPriority1 parameter specifies the value of the priority1 field used by the BMCA (Best Master Clock algorithm). It is the first parameter to be consulted by the default BMCA. Thus it overrides the clock class and quality selection criteria.
Note: The lower the value is, the higher the priority is.
Note: Do not change the value from the default value, if the parameter is not used. In this way all PTP clocks in the domain have the same value and the priority functionality is disabled.
Note: For the PTP Power profile the range is restricted to only one value, namely 255.
The PtpClockPriority2 parameter specifies the value of the priority2 field used by the BMCA (Best Master Clock algorithm). It is consulted by the BMCA just after the clock class and accuracy fields have been checked. It can be used to give a particular clock device precedence over other clocks with equal clock quality.
Note: The lower the value is, the higher the priority is.
Note: Do not change the value from the default value, if the parameter is not used. In this way all PTP clocks in the domain have the same value and the priority functionality is disabled.
Note: For the PTP Power profile the range is restricted to only one value, namely 255.

PTP clock domains

In PTP networks you can specify multiple PTP clock domains using the same communication medium, for instance Ethernet. Each domain is completely isolated from other domains and can therefore be seen as different PTP networks. The PtpClockDomain parameter specifies the domain No. for the SmartNIC.
Note: For the PTP Telecom profile the range is restricted to between 4 and 23.

PTP announce message interval

In multicast master mode, the PtpAnncInterval parameter specifies the time interval in units of log2 seconds between sending 2 adjacent announce messages. In unicast slave mode, the parameter specifies the time interval in units of log2 seconds between 2 adjacent announce requests.
Note: For the PTP Telecom profile the range is restricted to between –3 and 4. For the PTP Power profile and the PTP Enterprise profile the range is restricted to only one value, namely 0.

PTP announce time-out multiplier

The PtpAnncTmo parameter specifies the announce time-out multiplier. If a PTP slave is synchronized to a master clock, the announce messages are constantly monitored. When these messages disappear, the time-out value in seconds to use before abandoning the master is calculated as: 2^(announce interval) * (announce time-out multiplier).
Note: For the PTP Power profile the range is restricted to only one value, namely 3.

PTP synchronization message interval

In unicast slave mode, the PtpSynInterval parameter specifies the time interval in units of log2 seconds between 2 adjacent synchronization requests.
Note: For the PTP Telecom profile the range is restricted to between –7 and 4. For the PTP Power profile the range is restricted to only one value, namely 0.

Minimum PTP delay request interval

In PTP slave mode, the PtpDelrMinInterval parameter specifies the initial value used before receiving an update in a delay response message from the master. In unicast slave mode, the parameter specifies the minimum time interval in units of log2 seconds between 2 adjacent delay requests.
Note: For the PTP Telecom profile the range is restricted to between –7 and 4. For the PTP Power profile the range is restricted to between -1 and 6.

PTP peer delay request interval

The PtpPDelInterval parameter only applies when the peer-to-peer delay mechanism is selected (see Applying a PTP Delay Mechanism). It specifies the delay request interval in units of log2 seconds.
Note: For the PTP Power profile the range is restricted to only one value, namely 0.

PTP communication protocol

The PtpCommTech parameter specifies the communication transport protocol to use.
Note: For the PTP Telecom profile and the PTP Enterprise profile the parameter can only take one value, namely IPv4/UDP.For the PTP Power profile the parameter can only take one value, namely IEEE_802.3.

PTP user description

The PtpUserDescription parameter allows the user to add a description string to the SmartNIC clock. This string can be retrieved from the userDescr parameter in the clock description information in the information stream. It can also be retrieved from the PTP management interface.

ntservice.ini code line

The syntax for the ntservice.ini code line configuring the PTP clock is:

'PtpClockPriority1' '=' ( '0' | '1' |  '2' | ... |  '255' )
'PtpClockPriority2' '=' ( '0' | '1' |  '2' | ... |  '255' )
'PtpClockDomain' '=' ( '0' | '1' |  '2' | ... |  '128' )
'PtpAnncInterval' '=' ( '–3' | '–2' |  '–1' | '0' | '1' |  '2' | ... |
 '6' )
'PtpAnncTmo' '=' ( '2' | '3' |  '4' | ... |  '10' )
'PtpSynInterval' '=' ( '–7' | '–6' |  '–5' | ... | '0' | '1' |  '2' |
 ... | '6' )
'PtpDelrMinInterval' '=' ( '–7' | '–6' |  '–5' | ... | '0' | '1' |
  '2' | ... | '6' )
'PtpPDelInterval' '=' ( '–6' | '–5' |  '–4' | ... | '0' | '1' |
  '2' | ... | '5' )
'PtpCommTech' '=' ( 'IPv4/UDP' | 'IEEE_802.3' )
'PtpUserDescription' '=' <ASCII character> { <ASCII character> }

Example:

PtpClockPriority1=1
PtpClockPriority2=2
PtpClockDomain=100
PtpAnncInterval=2
PtpAnncTmo=10
PtpSynInterval=–4
PtpDelrMinInterval=6
PtpPDelInterval=3
PtpCommTech=IEEE_802.3
PtpUserDescription=NT20E3-2-PTP

Default values

This table shows the default values.

Parameter Default Value
PtpClockPriority1

For the PTP Default, Telecom and Enterprise profiles:

128

For the PTP Power profile:

255
PtpClockPriority2

For the PTP Default, Telecom and Enterprise profiles:

128

For the PTP Power profile:

255
PtpClockDomain

For the PTP Default, Power and Enterprise profiles:

0

For the PTP Telecom profile:

4
PtpAnncInterval

For the PTP Default and Telecom profiles:

1

For the PTP Power and Enterprise profiles:

0
PtpAnncTmo

For the PTP Default, Power and Enterprise profiles:

3

For the PTP Telecom profile:

2
PtpSynInterval 0
PtpDelrMinInterval 0
PtpPDelInterval 0
PtpCommTech

For the PTP Default, Telecom and Enterprise profiles:

IPv4/UDP

For the PTP Power profile:

IEEE_802.3
PtpUserDescription Napatech adapter