diff --git a/doc/faq.adoc b/doc/faq.adoc index 732aa80..257e301 100644 --- a/doc/faq.adoc +++ b/doc/faq.adoc @@ -345,6 +345,15 @@ server ntp.local minpoll -6 maxpoll -6 filter 15 xleave hwtimestamp eth0 minpoll -6 ---- +Since `chrony` version 4.3, the minimum `minpoll` is -7 and a filter using a +long-term estimate of a delay quantile can be enabled by the `maxdelayquant` +option to replace the default `maxdelaydevratio` filter, which is sensitive to +outliers corrupting the minimum delay. For example: + +---- +server ntp.local minpoll -7 maxpoll -7 filter 31 maxdelayquant 0.3 xleave +---- + As an experimental feature added in version 4.2, `chronyd` supports an NTPv4 extension field containing an additional timestamp to enable frequency transfer and significantly improve stability of synchronisation. It can be enabled by