Re: [ntp:questions] NTP absolute accuracy?

"David J Taylor" writes: >"Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps82... >[] >> Note that chrony will give you a factor of 2 or three improvement over >> ntp in the errors, assuming that the roundtrip is equally split on >> Linux or BSD. >For those without wide-bandwidth ac

Re: [ntp:questions] NTP absolute accuracy?

David J Taylor wrote: > "Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps82... > [] >> Note that chrony will give you a factor of 2 or three improvement over >> ntp in the errors, assuming that the roundtrip is equally split on >> Linux or BSD. > > For those without wide-bandwidth aca

Re: [ntp:questions] NTP absolute accuracy?

David J Taylor wrote: > For those without wide-bandwidth academic connections - those folks on > cable or ADSL - how good is an "equal split round trip" assumption? I calculated this for my case once (3840 kbit/s down and 512 kbit/s up). The difference in transmission time due only to the differe

Re: [ntp:questions] NTP absolute accuracy?

"David J Taylor" wrote in message news:%xqgm.126$ym4...@text.news.virginmedia.com... > "Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps82... > [] >> Note that chrony will give you a factor of 2 or three improvement over >> ntp in the errors, assuming that the roundtrip is equally

Re: [ntp:questions] NTP absolute accuracy?

David J Taylor wrote: > > "David J Taylor" > wrote in > message news:%xqgm.126$ym4...@text.news.virginmedia.com... >> "Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps82... >> [] >>> Note that chrony will give you a factor of 2 or three improvement over >>> ntp in the errors, assum

Re: [ntp:questions] NTP absolute accuracy?

Jan Ceuleers wrote: > This is however only the best case, because it assumes that the > uplink is not saturated. If it is, and if you are able to prioritise your I suspect most severe asymmetry cases actually happen because the downlink is saturated. That's is exacerbated by the fact that it is

Re: [ntp:questions] NTP absolute accuracy?

David Woolley wrote: > I suspect most severe asymmetry cases actually happen because the > downlink is saturated. That's is exacerbated by the fact that it is > more difficult to get the ISP to prioritise, than to do it yourself. There is no point to large amounts of buffering in the ISP's edge r

Re: [ntp:questions] NTP absolute accuracy?

"David J Taylor" writes: >"David J Taylor" > wrote in >message news:%xqgm.126$ym4...@text.news.virginmedia.com... >> "Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps82... >> [] >>> Note that chrony will give you a factor of 2 or three improvement over >>> ntp in the errors, assu

Re: [ntp:questions] NTP absolute accuracy?

David J Taylor writes: > On consumer-grade circuits the assumption about equal round trip is > unlikely to be valid. Why would you expect the asymmetry to be worse there than elsewhere? -- John Hasler jhas...@newsguy.com Dancing Horse Hill Elmwood, WI USA ___

Re: [ntp:questions] NTP absolute accuracy?

"Unruh" wrote in message news:qg_gm.50009$db2.46...@edtnps83... > "David J Taylor" > writes: > > >>"David J Taylor" >> wrote in >>message news:%xqgm.126$ym4...@text.news.virginmedia.com... >>> "Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps82... >>> [] Note that chrony will

Re: [ntp:questions] NTP absolute accuracy?

"David J Taylor" writes: >"Unruh" wrote in message >news:qg_gm.50009$db2.46...@edtnps83... >> "David J Taylor" >> writes: >> >> >>>"David J Taylor" >>> wrote in >>>message news:%xqgm.126$ym4...@text.news.virginmedia.com... "Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps82

Re: [ntp:questions] NTP absolute accuracy?

> David J Taylor writes: >> On consumer-grade circuits the assumption about equal round trip is >> unlikely to be valid. > > Why would you expect the asymmetry to be worse there than elsewhere? > -- > John Hasler It's just an impression I had - that consumers get the worst latency and most overl

Re: [ntp:questions] NTP absolute accuracy?

"Unruh" <> wrote in message news:kx%gm.50022$db2.12...@edtnps83... [] > As I said, chrony does a linear regression on the last n offsets. [] Bill, I think we have seen these remarks about chrony before. What I was wanting was a yes/no answer (although numbers would be nice) to the question: -

Re: [ntp:questions] NTP absolute accuracy?

David J Taylor writes: > It's just an impression I had - that consumers get the worst latency > and most overloaded network equipment... Perhaps, but it doesn't follow that they suffer a great deal of asymmetry. > ...and no direct connection to an ultra-high-speed academic network. Of course not

Re: [ntp:questions] NTP absolute accuracy?

David J Taylor wrote: > > "Unruh" wrote in message > news:qg_gm.50009$db2.46...@edtnps83... >> "David J Taylor" >> writes: >> >> >>> "David J Taylor" >>> wrote in >>> message news:%xqgm.126$ym4...@text.news.virginmedia.com... "Unruh" <> wrote in message news:34jgm.50898$ph1.36...@edtnps8

Re: [ntp:questions] NTP absolute accuracy?

David Lord writes: >David J Taylor wrote: >> >> "Unruh" wrote in message >> news:qg_gm.50009$db2.46...@edtnps83... >>> "David J Taylor" >>> writes: >>> >>> "David J Taylor" wrote in message news:%xqgm.126$ym4...@text.news.virginmedia.com... > "Unruh" <> wrote in message n

Re: [ntp:questions] NTP absolute accuracy?

"David J Taylor" writes: >"Unruh" <> wrote in message news:kx%gm.50022$db2.12...@edtnps83... >[] >> As I said, chrony does a linear regression on the last n offsets. >[] >Bill, >I think we have seen these remarks about chrony before. Some have, some have not. I was just putting out there wha

Re: [ntp:questions] NTP absolute accuracy?

Unruh wrote: > David Lord writes: > >> David J Taylor wrote: >>> "Unruh" wrote in message >>> news:qg_gm.50009$db2.46...@edtnps83... "David J Taylor" writes: > "David J Taylor" > wrote in > message news:%xqgm.126$ym4...@text.news.virginmedia.com... >> "Unr