On Tue, 5 May 2015 22:54:03 -0700, Steve Allen wrote: > Like the TymServe 2100 units there will probably be other systems that > fail because of a lack of leap seconds. That means that 45 years ago > the CCIR put us all into a Catch-22 situation, and the ITU-R inherits > the undesired responsibility of doing or not doing something about it. > > On Tue 2015-05-05T21:37:48 -0600, Warner Losh hath writ: >> Engineering is the choice of which consequences you want to have. > > It should be an informed choice, and an individual choice, and a > choice. What gets broadcast in the radio time signals is none of > those, and that is presumably a major motivation for the adoption of > IEEE 1588 (PTP). IEEE 1588 gives those system managers a way to > choose to disregard certain international standards in favor of a > system with guaranteed robust behavior. Such use of PTP is evident in > older documents and recent press releases by the financial markets > which basically read "We know our systems will be robust but we're not > sure about yours, so we're changing the trading hours on June 30."
The original impetus behind IEEE 1588 PTP was the US Navy. A big reason to desire something like 1588 was to eliminate most of the various time distribution systems on Navy ships, such as IRIG, combining everything into ethernet. There is a lot of money in this - cable plants are expensive, bulky, and heavy, and each independent distribution system requires lots of engineering labor to implement and interface. But I will agree that forcing propagation of TAI as a practical (versus paper) clock is one good side effect, but that isn't sufficient reason for the Navy to have spent all that money. Joe Gwinn _______________________________________________ LEAPSECS mailing list [email protected] https://pairlist6.pair.net/mailman/listinfo/leapsecs
