Re: [Linuxptp-users] List of Boundary clocks

[Mozhdeh K. <kam...@gm...>]

The goal of my test is to study the probability of extending IEEE1588 to
larger networks. So I focus on delay between the master (GM) and slave in
different part of networks.
I chose ptplinux because it support boundary clocks(use of BC in
unavoidable in larger network) although it does not support hw timestamp,
the ptpd support hw time stamp but nor boundary clock. I decide to do
emulation and buy the necessary hardware. So,
I thought of running linuxptp on different virtual machines, connect these
VM with GRE tunnel together, connect the VM which is suppose to be boundary
clock to special  PCI that has hw timestamping. Add jitter by TC command in
linux,  and do the test. So, according to that idea, I should buy a PC with
multiple slot for PCI, buying PCI that support hw time stamp (for boundary
clocks with several port).
What do you think of this idea? Do you have any suggestion for the hardware
I should buy?

BR,
Mozhdeh
On Tue, Apr 9, 2013 at 2:34 PM, Miroslav Lichvar <mli...@re...>wrote:

> 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
>



-- 
*Mozhdeh *