In article <4a15e001$0$18238$da0fe...@news.zen.co.uk>, Andy Yates <andyy1...@gmail.com> 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.
>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. What sort of accuracy are you interested in? 1 ms? 10 ms? 100 ms? How stable is your temperature? (Both the room and the CPU load.) What is the load on the LAN between the clients and servers? (Delay is not a problem. Variation in delay is a problem.) I suggest you measure it. Start with your current system. Setup a box as a ntpd system and tell it to use several target boxes as servers and turn on logging. peerstats will tell you the difference between your local clock and the target system. -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions