On Fri, Nov 19, 2021 at 03:16:49AM -0800, Methlal Pallewatta wrote:
> In the section 6.6.4 (page 35) of the IEEE Std 1588-2008 the following is
> stated about the port 2 in the P2P mode.
> 
> Port-2 either:
> 1. returns the difference between the timestamps t2 and t3 in the
> Pdelay_Resp message
> 2. returns the difference between the timestamps t2 and t3 in a
> Pdelay_Resp_Follow_Up message
> 3. returns the timestamps t2 and t3 in the Pdelay_Resp and
> Pdelay_Resp_Follow_Up messages,
> respectively

Yes, but actually, the exact steps are spelled out starting on page 114:

    11.4.3 Peer delay mechanism operational specifications
 
> I found that the IXIA master that I used was using option 2 and was not
> sending the actual timestamp t2 but sending out 0 instead.

The action of the "delay requestor" is the same in any case, and this
is spelled out starting on page 115:

    1) Generate timestamp t4 upon receipt of the Pdelay_Resp message

    2) If asymmetry corrections are required, modify the
       correctionField of the Pdelay_Resp message per 11.6.5

    3) If the twoStepFlag of the received Pdelay_Resp message is FALSE, 
indicating that no
       Pdelay_Resp_Follow_Up message will be received, compute the 
<meanPathDelay> as:
       <meanPathDelay> = [(t4 - t1) - correctionField of Pdelay_Resp]/2

    4) If the twoStepFlag of the received Pdelay_Resp message is TRUE 
indicating that a
       Pdelay_Resp_Follow_Up will be received, compute the <meanPathDelay> as 
follows:
       <meanPathDelay> = [(t4 - t1) - (responseOriginTimestamp - 
requestReceiptTimestamp) -
       correctionField of Pdelay_Resp - correctionField of 
Pdelay_Resp_Follow_Up]/2

Which part of that is linuxptp doing incorrectly?

> At the same time
> the Syncs were the actual timestamp as the originTimestamp.

How are Sync messages relevant here?

Thanks,
Richard


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