Re: [Linuxptp-devel] [PATCH RFC 0/6] Transparent Clock - third and final part

[Richard C. <ric...@gm...>]

On Fri, Apr 27, 2018 at 04:06:27PM +0200, Miroslav Lichvar wrote:
> That's for the case when the TC starts correcting messages
> immediately, just not having the correct frequency offset yet, right?

Right.
 
> If the TC doesn't make any corrections after start, the error is the
> residence time. With heavy network traffic the delays can be in tens
> of milliseconds or maybe even more?

I must have misunderstood you.  The TC must correct the residence
time.  The question is whether to apply the frequency correction to
the residence times reported in the correction field.

I thought you meant that the TC should drop packets until it has
measured the frequency offset.  Because the error in the residence
time is so small when free running, I think it better to simply apply
the frequency correction to the residence time when it becomes
available (two or four seconds after the TC boots).

> I'm wondering how do real switches with TC support behave on start.

(*We* are going to be the "real" switch ;)

Thanks,
Richard