>> According to 802.1 AS all message timestamps shall be based on a free running clock (LocalClock) in order to minimize the errors resulting from a varying clock frequency.
>> Also phase discontinuities in the pdelay_resp(fup) messages are avoided this way.
>> So the SlaveClock controlled by the servo is different from the hardware clock taking the timestamps.
>> An implementation would require to translate hardware timestamps into the SlaveClock epoch to compute the master offset correctly.
>> 
>> I was not able to find this behavior implemented in linuxptp. Did I miss something, or was this already issued?

>You are mistaken.  The master offset is irrelevant for TC operation.
>The TC is supposed to syntonize only.

You are right, a plain TC does not need the offset.

My use case is a bridged end-station, i.e. a time-aware bridge with an application that needs to be synchronized.
The AS model of operation allows every time-aware system (including TAB) to include a ClockSlave and provide an application interface to a ClockTarget.

Syntonization is done by multiplying the residence time with the rate ratio, no servo needed, right?
So the servo should be free for synchronizing the ClockSlave but this requires the offset.
Would this be possible with linuxptp?
Any advice is appreciated.

Regards,
Burkhard