[ncs540] Please explain slow-tracking

[sjrcoel]

I wonder what kind of

slow-tracking

technology is used by

ncs540

Below is an example. Please refer to it when explaining
configure terminal

!
ptp
servo-slow-tracking 16
!
show configuration
!
commit

[Torbjørn]

PTP slow tracking

defines that the servo(servo clock algorithm) should correct the phase offset based on the number of nanoseconds defined, instead of reacting immediately to any time offset it receives. You can read more about

PTP and slow tracking

here: https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5500/sysman/72x/b-system-management-cg-ncs5500-72x/b-system-management-cg-ncs5500-72x_chapter_01011.html#Cisco_Concept.dita_63a0fc6f-3627-4521-a446-2b1b7ad6b72c

[M02@rt37 · Accepted solution]

Hello @sjrcoel,

The configuration you've provided is related to Precision Time Protocol

PTP

specifically the

servo-slow-tracking

feature on a Cisco NCS540 router.

PTP

is a protocol used for synchronizing the time across network devices with high precision.

Servo-slow-tracking

is a mechanism that allows a

PTP

device to make gradual adjustments to its clock, avoiding sudden or large changes. This is important in cases where maintaining time synchronization is critical, and abrupt changes could cause issues in the network.

You're configuration in details:

ptp

This command is used to enter the

PTP

configuration mode, where you can configure various

PTP

related settings.

 servo-slow-tracking 16

This command configures the

servo-slow-tracking

feature with a value of 16. This value represents the number of

PTP

servo seconds it takes for the clock to gradually adjust or "track" any discrepancies. In other words, if there is a time synchronization error, the clock will make gradual adjustments over a period of 16

PTP servo seconds

to minimize abrupt changes in time.


In this context,

servo-slow-tracking

is a mechanism that helps ensure that time synchronization adjustments are made gradually and smoothly, rather than making sudden and potentially disruptive changes to the system clock. The value "16" represents the time period over which these adjustments occur.