Subject: [pm-dir] Benoit Claise's No Objection on draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric-01: (with COMMENT)

From: "Benoit Claise" <[email-masked]>
Date: Thu, 20 Feb 2014 04:04:42 -0800

Benoit Claise has entered the following ballot position for
draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric-01: No Objection

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COMMENT:
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I put myself in the shoes of the operator looking at the different
extended reports, and I'm trying to understand how to correlate the
number of discarded bytes with  number of discarded packets from the
different extended reports.

>From the document, there could be 3 different extended reports reporting
the number of discarded packets:

   o  Reporting the number of discarded packets in a measurement
      interval, i.e., during either the last reporting interval or since
      the beginning of the session, as indicated by a flag in the
      suggested XR report [RFC7002].  If an endpoint needs to report
      packet discard due to other reasons than early- and late-arrival
      (for example, discard due to duplication, redundancy, etc.)  then
      it should consider using the Discarded Packets Report Block
      [RFC7002].

   o  Reporting gaps and bursts of discarded packets during a
      measurement interval, i.e., the last reporting interval or the
      duration of the session [RFC7003].

   o  Reporting run-length encoding of discarded packet during a
      measurement interval, i.e., between a set of sequence numbers
      [I-D.ietf-xrblock-rtcp-xr-discard-rle-metrics].

First of all, it would be nice to mention that the measurement intervals
from the different extended reports are synchronized.
Talking to Dan Romacanu (btw thanks Dan), I understand that the number of
bytes can be correlated to the number of packet in bullet 1 (RFC 7002)
and/or in the bullet 3 ([I-D.ietf-xrblock-rtcp-xr-discard-rle-metrics]),
depending on the flag value expressing whether we speak about delta or
running counters.
A few sentences (or a new section) about this would be an extremely
useful addition from an operational point of view.

Note: it was confusing to me that 
[I-D.ietf-xrblock-rtcp-xr-discard-rle-metrics] refers to
http://tools.ietf.org/html/draft-ietf-xrblock-rtcp-xr-discard-rle-metrics-06,
a very old version of the draft ... which still contains the bytes
extended report. Mentioning RFC 7097 obviously solves that one. Thanks
again Dan for gently highlighting the obvious to me :-)

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From: Varun Singh <[email-masked]>
Date: Fri, 21 Feb 2014 12:55:59 +0200

Hi Benoit,

Comments inline.

Cheers,
Varun

On 20 Feb 2014, at 14:04, Benoit Claise <[email-masked]> wrote:

> from the different extended reports are synchronised.
Instead of creating another section or adding the comment to the Introduction,
I suggest adding it to Section 4, where the document discusses protocol 
operation.

NEW TEXT:

4.1.  Reporting Node (Receiver)

   The media receiver MAY send the Bytes Discard Reports as part of the
   regularly scheduled RTCP packets as per RFC3550.  It MAY also include
   Bytes Discard Reports in immediate or early feedback packets as per
   [RFC4585].

   Transmission of RTCP XR Bytes Discarded Report is up to the
   discretion of the media receiver, as is the reporting granularity.
   However, it is RECOMMENDED that the media receiver signals the bytes
   discarded packets using the method defined in this document.  When
   reporting several metrics in a single RTCP packet, the reporting
   intervals for the report blocks are synchronized, therefore the media
   receiver may choose to additionally send the Discarded Packets
   [RFC7002] or Discard RLE [RFC7097] Report Block to assist the media
   sender in correlating the bytes discarded to the packets discarded in
   that particular interval.

   If all packets over a reporting period were discarded, the media
   receiver MAY use the Discarded Packets Report Block [RFC7002]
   instead.

> again Dan for gently highlighting the obvious to me :-)

Will be fixed in the upcoming version.

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From: Benoit Claise <[email-masked]>
Date: Tue, 25 Feb 2014 00:02:13 +0100

Hi Varun,

That would be helpful. Thanks.

Regards, Benoit
> .