[ntp:questions] Question on "calldelay"

Danny Mayer mayer at ntp.isc.org
Mon May 7 11:29:16 UTC 2007

Uwe Klein wrote:
> Danny Mayer wrote:
>> The protocol doesn't care. This is UDP. If it doesn't get a response it
>> will try again later. When later is depends on the stage that it's at.
> Right udp per se does not care.
> what about ntpd:
> at what moment in the exchange is the calldelay rundown started ?

In this case I meant NTP and not UDP. Sorry for not being clear on this.
NTP was originally written when networks were much more unreliable than
they are today so packet loss was a normal fact of life. NTP if it
doesn't receive a response just tries again at its next scheduled time.

> I have looked into ntp_proto.c where this is handled
> but am currently not through understanding the state stepping.

Not surprising. I too find some of the code difficult to understand.


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