Hi Which all sort of begs the question:
Why not a simple “broadcast UDP” once a second time packet approach for a home LAN? Unless you get really crazy, it’s not going to be a very big packet. Seconds since some arbitrary point in time. Time zone offset. Maybe a leap second count. Server ID maybe. Less than 100 bytes not including the overhead. Bob > On Aug 15, 2019, at 5:36 AM, Hal Murray <hmur...@megapathdsl.net> wrote: > > > ausserirdischesindges...@gmail.com said: >> I am a newbie and am wondering what options there are for exchanging time >> on a more basic level than NTP or PTP (that is for situations when a >> full network stack is too complex). > > You haven't described your problem fully yet. > > Are you interested in client side or server side? (or both) > > What sort of environment are you working in? What sort of hardware do you > have available? > > NMEA over a serial port is probably what you want, but... > > > Raspberry Pi and similar are not very expensive. They come with networking > software. The Pi isn't very nice for time-nut work over the net because the > Ethernet is on USB which adds jitter and/or hanging bridges. It does have > GPIO. > > > There is a lot of things you can do without a "full network stack". > > What level of hacking is reasonable depends on your environment. For a setup > at home, you are unlikely to annoy anybody else. > > The Alto firmware could boot over the (3 MB) Ethernet. The boot servers > would > periodically send a boot-loader packet to a reserved hardware address. The > firmware only had to setup the hardware to receive a packet, wait for one, > sanity check things, and jump to it. > > If you use UDP rather than TCP, the "stack" level packet format is much > simpler. Retransmission becomes trivial if you only have one un-ACKed packet > to consider. Performance on a LAN is OK most of the time. > > For something like a NTP server, you can avoid routing and ARP by sending the > reply back where it came from. > > For the client side, the normal problem is finding the server. If you only > have one server, you can wire in the address. > > > > > -- > These are my opinions. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- firstname.lastname@example.org > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- email@example.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.