Re: [xrblock] Fw: I-D Action: draft-ietf-xrblock-rtcp-xr-jb-02.txt

[Kevin Gross <[e-mail]>]

Sorry for the delay in getting these comments published. I had originally
reviewed version 01. Some of my minor comments were resolved in this new
version and so are not included here.


Section 1.2

RFC 3611 is still in force -
s/[RFC3611] defined/[RFC3611] defines


Section 1.3

Missing conjunction -
s/guidelines in [RFC6390][RFC6792]/guidelines in [RFC6390] and [RFC6792]


Section 3.2

Jitter Buffer Configuration
I think the two reporting options are potentially over simplification of
how these systems can work. An adaptive receiver has to adapt to maximum
latency and to delay variation. The former is accomplish by adjusting the
playout delay, the latter by reallocating buffer space. I suggest we might
want to report these behaviors separately, for example:
  00 - fixed jitter buffer and delay
  10 - adaptive playout delay
  01 - adaptive buffer size
  11 - adaptive delay and size

Block length
Is requirement to discard reports with unexpected length
common practice with these reports? The alternative is to allow reports to
be revised to increased size with appended data. Original implementations
then ignore anything beyond the original size. It's a little more flexible
but maybe we don't want to go there. I've checked RFC 3611 and don't see
any guidance on this. It would be nice to specify consistent behavior
around this for all reports.

Jitter buffer nominal delay
Needs to specify reference points for reported delay: From receipt to
playout? From RTP timestamp to playout?
If one of the reference points is a playout time, and depending on expected
use cases, higher resolution may be justified here.

Jitter buffer maximum delay
Needs to specify reference points for reported delay: From receipt to
playout? From RTP timestamp to playout?

Another clarification -
s/correspond to the nominal size./correspond to the size of the jitter
buffer.

Jitter buffer high water mark
Explain whether this applies to fixed jitter buffer or only to adaptive.

Jitter buffer low water mark
Explain whether this applies to fixed jitter buffer or only to adaptive.


Kevin Gross
[phone]
Media Network Consultant
AVA Networks - www.AVAnw.com <http://www.avanw.com/>, www.X192.org



On Mon, Nov 26, 2012 at 5:51 PM, Qin Wu <[e-mail]> wrote:

> Sorry, I forgot what Kevin said in the last presentation.
> I think Dan's proposal looks good.:-)
>
> Regards!
> -Qin
> ----- Original Message -----
> From: "Romascanu, Dan (Dan)" <[e-mail]>
> To: "Varun Singh" <[e-mail]>
> Cc: "Qin Wu" <[e-mail]>; <[e-mail]>
> Sent: Monday, November 26, 2012 9:25 PM
> Subject: RE: [xrblock] Fw: I-D Action: draft-ietf-xrblock-rtcp-xr-jb-02.txt
>
>
> Indeed, this was Kevin Gross.
>
> The question is whether Kevin's comments could be made during the WGLC, or
> they are severe enough to make us wait before issuing a LC. I hope that
> Kevin can answer this.
>
> Thanks and Regards,
>
> Dan
>
>
>
> > -----Original Message-----
> > From: Varun Singh [mailto:[e-mail]]
> > Sent: Monday, November 26, 2012 3:18 PM
> > To: Romascanu, Dan (Dan)
> > Cc: Qin Wu; [e-mail]
> > Subject: Re: [xrblock] Fw: I-D Action: draft-ietf-xrblock-rtcp-xr-jb-
> > 02.txt
> >
> > Hi,
> >
> > AFAIR, someone (maybe Kevin Gross) remarked that he had some comments on
> > the draft.
> >
> > Regards,
> > Varun
> >
> > ----
> > http://www.netlab.tkk.fi/~varun
> >
> > On 26.11.2012, at 18.10, "Romascanu, Dan (Dan)" <[e-mail]>
> > wrote:
> >
> > > Thanks, Qin.
> > >
> > > Unless somebody has good reasons to object we shall issue the last
> > call in the coming days.
> > >
> > > Regards,
> > >
> > > Dan
> > >
> > >
> > >
> > >> -----Original Message-----
> > >> From: [e-mail] [mailto:[e-mail]] On
> > >> Behalf Of Qin Wu
> > >> Sent: Monday, November 26, 2012 10:57 AM
> > >> To: [e-mail]
> > >> Subject: [xrblock] Fw: I-D Action:
> > >> draft-ietf-xrblock-rtcp-xr-jb-02.txt
> > >>
> > >> On 26 November , 2012 4:54 PM, [e-mail] wrote:
> > >>>
> > >>> A New Internet-Draft is available from the on-line Internet-Drafts
> > >> directories.
> > >>> This draft is a work item of the Metric Blocks for use with RTCP's
> > >> Extended Report Framework Working Group of the IETF.
> > >>>
> > >>> Title           : RTP Control Protocol (RTCP) Extended Report (XR)
> > >> Block for Jitter Buffer Metric Reporting
> > >>> Author(s)       : Alan Clark
> > >>>                         Varun Singh
> > >>>                         Qin Wu
> > >>> Filename        : draft-ietf-xrblock-rtcp-xr-jb-02.txt
> > >>> Pages           : 14
> > >>> Date            : 2012-11-26
> > >>>
> > >>> Abstract:
> > >>>  This document defines an RTP Control Protocol (RTCP) Extended
> > >>> Report
> > >>>  (XR) Block that allows the reporting of Jitter Buffer metrics for a
> > >>> range of RTP applications.
> > >>>
> > >>>
> > >>> The IETF datatracker status page for this draft is:
> > >>> https://datatracker.ietf.org/doc/draft-ietf-xrblock-rtcp-xr-jb
> > >>
> > >>
> > >> [Qin]: I believe this version address resolve the comments discussed
> > >> in the last Atalanta IETF meeting and now is ready for WGLC.
> > >> _______________________________________________
> > >> xrblock mailing list
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