In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] wrote: > On Dec 1, 3:07 pm, Joseph Gwinn <[EMAIL PROTECTED]> wrote: > > In article > > <[EMAIL PROTECTED]>, > > > > [EMAIL PROTECTED] wrote: > > > Does anybody know of any *practical* samples on how to > > > implement NTP/SNTP client?. The goal is to provide accurate > > > time for a program/client running on Windows Vista. > > > > > Specifically, what values to include in the the request message, > > > how to process the reply message, etc. > > > > > I am NOT asking how to send/receive UDP datagrams, or where > > > to find comprehensive descriptions like RFC documents, or how > > > to build or design user interfaces. > > > > > Only a narrow description focused on NTP/SNTP request/reply > > > datagrams for a simple PC client, preferably in C/C++ source > > > code. > > > > I've done this in an embedded realtime system. (No, the source code is > > not available.) > > > > In Appendix A of RFC-1305 you will find the format of the NTPv3 > > request/response packet. Send this packet to port 123 of the NTP > > server, and read the reply packet. It's pretty easy. > > > > I saw this format. From data comm point of view it is very unusual > to have the same format for request and reply. > > Sending/receiving the packet to port 123 is the first thing I tried. > This is not an issue. The issue is to use all the values in > request and reply correctly and reliably. And the quickest > way is to get as many ***samples*** as possible, the > RFC doc ***alone*** is the slowest way.
Umm. You might wish to read the rest of RFC-1305. It really was not hard to get times from the server, or to be a server. If you want to do the full NTP, then the easiest solution is to use NTP itself. In the embedded realtime system I mentioned, we were actually implementing the timeserver, to allow ordinary UNIX boxes to use NTP to synchronize to our purpose-built time hardware, so all boxes in the system were using the same timescale. Joe Gwinn _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
