Hi all, I'm looking for a good explanation about the following values retrieved from ntpq UNIX
Jitter Offset Noise Stability Buffer Frequency I spent a lot of time on google but I didn't find any useful explanation. I need for it in order to write a document for a further new job opportunity. Anyone is keen to spent 5 minutes for me. So far, I found the following information Noise --> This is the control mechanism used to adjust the poll interval If the clock discipline offset is the maximum probability estimate of the clock error, the noise is the expected error in this estimate. Jitter --> Difference on reading time A reference clock will provide the current time, that's for sure. NTP will compute some additional statistical values that describe the quality of time it sees. Among these values are: offset (or phase), jitter (or dispersion), frequency error, and stability (See also Section 3.3). Thus each NTP server will maintain an estimate of the quality of its reference clocks and of itself. Synchronizing a client to a network server consists of several packet exchanges where each exchange is a pair of request and reply. When sending out a request, the client stores its own time (originate timestamp) into the packet being sent. When a server receives such a packet, it will in turn store its own time (receive timestamp) into the packet, and the packet will be returned after putting a transmit timestamp into the packet. When receiving the reply, the receiver will once more log its own receipt time to estimate the travelling time of the packet. The travelling time (delay) is estimated to be half of "the total delay minus remote processing time", assuming symmetrical delay Thank you! _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
