Re: [xrblock] 答复: 答复: 答复: 答复: Fw: I-D Action: draft-ietf-xrblock-rtcp-xr-jb-08.txt

[Kevin Gross <[e-mail]>]

Hi Qin,

Responses below.

Kevin

On Wed, Mar 20, 2013 at 6:45 AM, Qin Wu <[e-mail]> wrote:

> **
> Hi,Kevin:
> Thank for your quick checking.
> Please see my reply inline.
>
> Regards!
> -Qin
>
> ----- Original Message -----
> *From:* Kevin Gross <[e-mail]>
> *To:* Qin Wu <[e-mail]>
> *Cc:* Alan Clark <[e-mail]> ; [e-mail] ; Romascanu,
> Dan (Dan) <[e-mail]> ; Shida Schubert <[e-mail]>
> *Sent:* Sunday, March 17, 2013 6:10 AM
> *Subject:* Re: 答复: 答复: 答复: 答复: Fw: I-D Action:
> draft-ietf-xrblock-rtcp-xr-jb-08.txt
>
> I said my contributions were rough and it doesn't look like they were
> improved much in the new revision.
>
> Section 3
>
> "The delay applied to
>
>    packets that arrive at their expected time is known as the Nominal
>    Delay and this is equivalent to the late edge."
>
>
> Nominal delay is not equivalent to late edge.
>
>
>
> [Qin]: Please refer to example provide by Alan in Jan 16,2013 when clarifing to Roni on what nominal delay means.
>
> http://www.ietf.org/mail-archive/web/xrblock/current/msg01090.html
>
>
> One sentence in Alan's example I highlighted here is:
>
> "
>
> So the nominal delay is the time difference/ buffer size difference between the on-time insertion point and the point at which packets are read out and decoded.
>
> "
>
> So the nominal delay is equivalent to the time difference between the expected arrival time and the time when a late arriving packet is consumed.
>
> or we can say nominal delay is equivalent to late edge, what am I missing?
>
>
If we are not including decoder delay in this discussion, I think you're
right about this. I'm now too close to this to be able to tell whether it
is explained clearly. Hopefully others will review.

>
> Section 3.2
>
>
> "The fixed jitter buffers have a fixed size and the packets leaving
>    the jitter buffer have a constant delay."
>
>
> There is just one jitter buffer and we need a bit more elaboration on how a fixed jitter buffer is used, its limitations and how maximum delay and nominal delay are reported for it.
>
>
>
> [Qin]: I believe these have been explained in the Definition of Fields in Jitter Buffer Metrics Block of section 4.2.
>
>
I don't see it. Section 4.2 is the longest section. Fixed jitter buffer
term is used there but never defined or elaborated on. In any case, this
does not address my concern about singular vs. plural buffers and
subject-verb disagreement here.

>
> Section 3.3
>
>
> "An adaptive jitter buffer have variable size and variable delay."
>
>
> Fix grammar. Change "and" to "or" or "and/or".
>
>
>
> [Qin]: Agree, thanks.
>
>
Just to be clear, those are two separate complaints. There are several
instances of subject-verb disagreements. We can say those are just
editorial issues but I think they need to be addressed here because it it
is not always clear from context whether singular or plural is intended.