Andy Yates <[email protected]> writes: >Does anybody have any figures that shows the effect on accuracy of an >NTP v3 client using a stratum 1 server rather than a stratum 2 or 3 >server? It's all in a GE LAN based scenario, commercial stratum 1 >servers connected to GPS and stratum 2 and 3 servers are typically >dedicated Linux boxes.
>The reasons is that I would rather scale by adding strata - its a very >big data center with thousands of clients and has several "zones" that >are isolated. However some opinion is suggesting we run IRIG-B between >the GPS receiver and a bunch of stratum 1 servers and clients access >these directly. Much more expensive and any increase in accuracy from a >client experience may be negligible. >However I'm been pressed to supply an SLA for accuracy. My argument is >that although you can get your stratum one server to synchronize to >microseconds of UTP, as soon as the client uses NTP v3 over the LAN, >even a GE LAN, then the accuracy degrades and putting well designed well >specified stratum between the boxes is not going to decrease accuracy >sufficiently to warrant purchasing many stratum one appliances. I think you need some specifications. What accuracy do you really need? Without that you are simply wasting your, and everyones time and money. Direct GPS connection can give you 1 usec. Lan connection to those can give you 20usec average. Then each stratum will loose about 20-50 usec (my experience). Do you need better than msec >Thoughts? >Regards >Andy _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
