Re: [Linuxptp-users] HWTSTAMP_TX_ONESTEP_SYNC vs HWTSTAMP_TX_ON

[Keller, J. E <jac...@in...>]

On Mon, 2013-07-29 at 20:18 +0200, Richard Cochran wrote:
> On Mon, Jul 29, 2013 at 01:34:41PM +0000, Ledda William EXT wrote:
> > 
> > From my understanding of the PTP protocol, the one-step clock is "significant" only for the MASTER, e.g. it doesn't send the FOLLOW_UP because the "tx timestamp" is included in the SYNC. Is it correct? 
> 
> Yes and no.
> 
> This statement is true for E2E delay mechanism.
> 
> Theoretically, one step is also possible for the P2P mechanism, but I
> don't think any hardware implements that yet (and neither does
> linuxptp).
> 
> HTH,
> Richard

FYI, the i210 should have hardware support for doing onestep (no one
enabled it) and it could be configured to do either sync, or p2p delay,
but I don't believe it could do both. The i210 is configured by putting
in an offset of where in the packet you want the timestamp to go, but
you can't store different types of packets so it wouldn't work for P2P
packets.

- Jake