[time-nuts] SLIP vs Ethernet for NTP

[Chris Albertson]

On Sun, Oct 23, 2011 at 2:28 AM, Iain Young <iain at g7iii.net> wrote:
> Hi Guys,
>
> I have often heard it said that since RS-232 is more "deterministic",
> and suffers from less jitter, and uncertainties, than ethernet, that
> it makes a better medium for time distribution (no CDMA for a start).


I think this is only true if the Ethernet is using a shared media.
Like the old coax 10BaseT cables.   Modern system use switched
100BaseT that works much like a point to point link.   In fact if you
can do point to point RS232 why not point to point 100BaseT.  Just use
a crossover cable between two computers.

The "best" why to distribute time over an area that is small enough to
run cable is to distribute PPS.   Most cat-5 cable has unused pairs,
makes an easy way to send PPS.
Chris Albertson
Redondo Beach, California