Good feedback from Jon Mitchell, in his OPS-DIR review:

Indeed, TWAMP Test, and the time stamp format to be used, may be controlled by means other than TWAMP Control, e.g., local configurable knob exposed via data model or CLI. I'll work on text updates for the next version.

Regards,
Greg

On Fri, Mar 17, 2017 at 2:01 PM, Jon Mitchell <jrmitche@puck.nether.net> wrote:

    Reviewer: Jon Mitchell
    Review result: Has Nits

    I have reviewed this document as part of the Operational directorate's

    ongoing effort to review all IETF documents being processed by the
    IESG.  These
    comments were written with the intent of improving the operational
    aspects of the
    IETF drafts. Comments that are not addressed in last call may be
    included in AD reviews
    during the IESG review.  Document editors and WG chairs should treat
    these comments
    just like any other last call comments.

    Ready with Nits - this draft adds the ability to use PTP timestamps as
    an alternative to NTP timestamps for active performance measurement
    protocols OWAMP and TWAMP.  Although this draft does a good job of
    discussing interoperability for both sides of the session having or
    not having support for this operational capability, in several places
    it states that if a send/receiver support this capability it must be
    set to 1 in the flags.  However, only for TWAMP Light mode, this seems
    configurable.  This may just be my interpretation, but it probably
    should state that local implementations MAY provide a configurable
    knob to not negotiate PTPv2 timestamps in section 2.1 and 2.2 even if
    the capability is supported by the implementation.

Nit on the Security Considerations section. Higher resolution timestamps provide potential vehicles for side channel attacks on remote endpoints. This probably is not a huge issue, but it might be nice to mention it.