Hi Dhruv,
thank you for the clarification. I agree, using time format in this case is
not necessary at all.

Regards,
Greg

On Thu, Sep 15, 2016 at 8:59 PM, Dhruv Dhody <[email protected]> wrote:

> Hi Greg,
>
>
>
> The case with this draft is that IGP drafts [RFC7471] and [RFC7810] uses
> 24 bit integers for delay and delay variation already to flood this in
> TEDB.
>
> The PCEP [RFC5440] defined METRIC value as 32 bit IEEE floating point
> format. Changing that in this extension doesn’t seem wise.
>
>
>
> It is important to note that this draft is not about measurements, but how
> to use delay/delay-variation as constraints/criteria and use the date in
> TEDB for calculating a suitable E2E path (and thus before the path is setup
> and data flowing). I personally don’t see the benefit in changing format
> now.
>
>
>
> Thanks!
>
> Dhruv
>
>
>
> *From:* Greg Mirsky [mailto:[email protected]]
> *Sent:* 15 September 2016 23:00
> *To:* Dhruv Dhody <[email protected]>
> *Cc:* Alia Atlas <[email protected]>; The IESG <[email protected]>;
> [email protected]; [email protected];
> [email protected]
> *Subject:* Re: [Pce] Alia Atlas' No Objection on
> draft-ietf-pce-pcep-service-aware-12: (with COMMENT)
>
>
>
> Dear All,
>
> delay and delay variation are usually calculated using timestamps
> collected at two endpoints of the path. AFAIK, there are two formats, NTP
> and IEEE-1558v1/v2, being used in OAM protocols to measure Latency/Jitter
> with different precision determined by length of fractional seconds field.
> Hence my question, wouldn't it be easier, more intuitive to use one of the
> formats or, even better, allow both with explicit indication of the format
> being used, e.g. as in RFC 6734.
>
>
>
> Regards,
>
> Greg
>
>
>
> On Thu, Sep 15, 2016 at 9:14 AM, Dhruv Dhody <[email protected]>
> wrote:
>
> Hi Alia,
>
> Thanks for your comment, see inline...
>
>
> > -----Original Message-----
> > From: Pce [mailto:[email protected]] On Behalf Of Alia Atlas
> > Sent: 15 September 2016 19:13
> > To: The IESG <[email protected]>
> > Cc: [email protected]; [email protected];
> > [email protected]
> > Subject: [Pce] Alia Atlas' No Objection on
> > draft-ietf-pce-pcep-service-aware-12: (with COMMENT)
> >
> > Alia Atlas has entered the following ballot position for
> > draft-ietf-pce-pcep-service-aware-12: No Objection
> >
> > When responding, please keep the subject line intact and reply to all
> email
> > addresses included in the To and CC lines. (Feel free to cut this
> introductory
> > paragraph, however.)
> >
> >
> > Please refer to
> > https://www.ietf.org/iesg/statement/discuss-criteria.html
> > for more information about IESG DISCUSS and COMMENT positions.
> >
> >
> > The document, along with other ballot positions, can be found here:
> > https://datatracker.ietf.org/doc/draft-ietf-pce-pcep-service-aware/
> >
> >
> >
> > ----------------------------------------------------------------------
> > COMMENT:
> > ----------------------------------------------------------------------
> >
> > I am concerned that the 24 bit values of microseconds are being
> represented
> > in IEEE 32-bit floating point.
> > A quick look at conversions indicates that all integers will up to 6
> > significant figures can be converted without loss of precision.  That
> > implies that values of over 1 second may not be accurately sent.  It
> would
> > be useful to at least refer to the precision issue in the document.  I
> don't
> > expect that the loss of precision at the microsecond level is critical.
> >
> >
>
> [Dhruv] I could add a sentence for delay and delay variation -
>
>    The conversion from 24 bit integer to 32 bit IEEE
>    floating point could introduce some loss of precision.
>
> Will this be okay?
>
> Regards,
> Dhruv
>
>
>
> > _______________________________________________
> > Pce mailing list
> > [email protected]
> > https://www.ietf.org/mailman/listinfo/pce
>
> _______________________________________________
> Pce mailing list
> [email protected]
> https://www.ietf.org/mailman/listinfo/pce
>
>
>
_______________________________________________
Pce mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/pce

Reply via email to