[time-nuts] Serial port splitter s/w

[Brian Lloyd]

On Wed, Feb 26, 2014 at 2:05 PM, Chris Albertson
<albertson.chris at gmail.com>wrote:

> > Chris, even with Wi-Fi connected computers, mostly running Windows, there
> > is a huge difference between talking to a stratum-1 server on my LAN
> > compared to running just Internet servers.  Our experiences differ, as I
> am
> > on a cable modem connection from the UK's Virgin Media.  Folks need to
> > measure what performance they are getting and choose their own best path,
> > otherwise it's guesswork.
> >
>
> Yes, exactly.  It depends entirely on your internet connection.  As soon as
> you get even "slow" 10Mb/s fiber the distinction between LAN and Internet
> starts to melt away.  The problem with Cable TV is that it is a shared
> connection with who knows how many others.  Shared media have collisions
> with back off and retries and are not deterministic.
>

Not generally with broadband. (True broadband that is, such as
Internet-over-cable. I do find it annoying that all higher-speed, i.e.
non-dial-up, access is referred to as "broadband".) There are no collisions
coming downstream because there is only one source -- the head end. There
you just have variable queueing delays if a burst of traffic exceeding
downstream capacity arrives at once. Collisions are possible on the
upstream but less likely.

I do have a local NTP server.  I had one back in the days of dial-up phone
> modems and still have one with my current fiber connection.  I was just
> pointing out that the local NTP server is less useful as the Internet
> connections get better.
>

True, but far more deterministic. As you suggest, a local NTP server is
independent of upstream traffic, queueing, and backoff/retry delays.
Personally I would like to have a local stratum-1 source for that reason.

-- 
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
brian at lloyd.com
+1.916.877.5067