System transit time, Latency -

[jdow]

On 2012/04/07 08:39, Bob Goodwin - Zuni, Virginia, USA wrote:
> How can I measure system transit time in this satellite system.
> I don't need great precision, just a rough idea of the time from
> here to the satellite, back down to the earth station/gateway,
> destination, and return.
>
> I used to look at ntpq when I wanted a clue but that is
> apparently not available for F-16/64?
>
> I installed "latencytop" but I don't see how to use it for this
> purpose?

If it is TCP/IP all the way and you are speaking of two distinct end
points, you can get a fairly good idea by using "mtr system2" from
system1. You'll also see the delays at each hop as well. It's only
an indication. But it's better than nothing.

If I needed something more accurate I'd setup a TCP link with the nagle
algorithm turned off so data is sent instantly rather than cued up for
a variable period of time. This might require whipping up a suitable
tool if you don't have one. And you'd have to use the tool at both
ends of the path.

Of course, the easy way, since you cite ntpq working in the past for this
purpose, is to look for where Fedora stuck this important ntp performance
monitor. I can't believe they left it out. (No, I take it back. I can
believe almost any nonsense out of Fedora. Thankfully, they usually get
over it quickly enough.)

{^_^}