[ntp:questions] NTP over multicast sat link with no return channel

juliansomers at googlemail.com juliansomers at googlemail.com
Thu Apr 6 14:36:26 UTC 2006


Hello!

I have a number of linux machines to which I send multicast data over a
one-way dvb satellite link.

In addition to this dvb 'forward channel', these machines are able to
connect to the internet via a satellite phone 'return channel'. I am
currently running ntpd on them to sync the clock when they do connect
via sat-phone. But as the sat-phone sessions are brief and irregular,
this is not reliable enough. Sometimes months go by without any two-way
traffic.

In my dreams, I am able to set the clocks with a multicast time signal
over the one-way DVB channel, which is available at all times.

As far as I can tell, I can't use ntpd for this, as it won't work
unless there can be a two-way conversation between client and server. I
hope I am mistaken.

Is there any way it can be done?

Many thanks for your time,

Julian




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