[ntp:questions] stepping and slewing

Riccardo Castellani castellani.riccardo at tiscali.it
Thu May 3 23:14:52 UTC 2007

Look at carefully Steve Kostecke's message where he said:
step == reset the clock to the correct time in _one_ instantaneous step.
A stepped clock can "move backwards".

slew == adjust the clock by speeding it up or slowing it down. A slewed
clock never "moves backwards"

you can see slewed clock never moves backward, it can decelerate or
accelerate clock by 0.5 ms/sec, but not set time backward of several minutes

----- Original Message ----- 
From: Hal Murray
Newsgroups: comp.protocols.time.ntp
To: questions at lists.ntp.isc.org
Sent: Thursday, May 03, 2007 10:26 AM
Subject: Re: [ntp:questions] stepping and slewing

>Now I understand that stepping set clock immediately to correct time
>(both forward and backward) while slewing permit to adjust gradually
>time at max 0.5 ms /sec rate (ONLY forward). is'tt OK ?

Slewing can go in either direction.

To advance, the clock advances by 1.0005 seconds per real second.
To backup, it advances by 0.9995 seconds per second.

These are my opinions, not necessarily my employer's.  I hate spam.

questions mailing list
questions at lists.ntp.isc.org

More information about the questions mailing list