Re: [Linuxptp-users] List of Boundary clocks

[Miroslav L. <mli...@re...>]

On Mon, Apr 08, 2013 at 08:40:44PM +0200, Richard Cochran wrote:
> On Mon, Apr 08, 2013 at 04:17:46PM +0200, Mozhdeh Kamel wrote:
> > I mean, I am thinking of having several virtual machines (such as VBox),
> > run the linux PTP project on each on them. and I can connect them together
> > through GRE or other tunnel. Use TC on linux or NeteM to add delay and
> > jitter .
> 
> But without hardware time stamping, you are not going to get very good
> synchronization performance.

Depends on what exactly she wants to test. When I don't care about
accuracy and want to test the protocol itself, I use sometimes ptp4l
in qemu with the e1000 driver. If the delay and jitter was shifted by
tc to 10s or 100s of milliseconds, maybe it could be of some value for
performance testing too.

> Here is another simulation idea you could explore. It would be very
> interesting to be able to test the BMC in a simulated network, and to
> test the clock servos as well. Take a look at Miroslav Lichvar's clock
> and network simulator to get an idea of what can be done.
> 
>    http://mlichvar.fedorapeople.org/clknetsim
> 
> It would be a fair amount of programming, but you could then simulate
> the hardware timestamping as exactly as you wish.

I'd very much like to see ptp4l supported by clknetsim. The list of
things which I know are missing for the support includes:
- multiple timers
- multiple interfaces
- multicast
- some ioctls (hw time stamping)

Thanks,

-- 
Miroslav Lichvar