Re: [xrblock] WGLC fordraft-ietf-xrblock-rtcp-xr-burst-gap-discard-08.txt

[Qin Wu <[e-mail]>]

----- Original Message ----- 
From: "Colin Perkins" <[e-mail]>
To: "Qin Wu" <[e-mail]>
Cc: "Romascanu, Dan (Dan)" <[e-mail]>; <[e-mail]>
Sent: Thursday, December 13, 2012 12:11 AM
Subject: Re: [xrblock] WGLC fordraft-ietf-xrblock-rtcp-xr-burst-gap-discard-08.txt


On 12 Dec 2012, at 09:12, Qin Wu wrote:
> Hi,
> ----- Original Message ----- 
> From: "Colin Perkins" <[e-mail]>
> To: "Romascanu, Dan (Dan)" <[e-mail]>
> Cc: <[e-mail]>
> Sent: Wednesday, December 12, 2012 6:09 AM
> Subject: Re: [xrblock] WGLC fordraft-ietf-xrblock-rtcp-xr-burst-gap-discard-08.txt
> 
> On 6 Dec 2012, at 13:14, Romascanu, Dan (Dan) wrote:
>> This is a (second) Working Group Last Call for http://www.ietf.org/id/draft-ietf-xrblock-rtcp-xr-burst-gap-discard-08.txt.  
>> 
>> Please read and review this document, and send your comments, questions and concerns to the WG list before December 20, 2012. If you read the document, have no comments and you believe that the document is ready for submission to the IESG as a Standards Track document please send a short message as well to help us in determining the level of review and consensus. 
> 
> 
> This looks to be in good shape. Some minor points I noticed:
> 
> - The last paragraph of the definition of the Interval Metric Flag in Section 3.2 might be clearer written “Burst/Gap Discard Metrics can only be measured over definite intervals, and cannot be sampled. Accordingly, the value I=01, indicating a sampled value, MUST NOT be used.”
> 
> [Qin]: Good proposed change, thanks.
> 
> - For Packets discarded in bursts and Total packets expected in bursts, why are the values 0xFFFFFE and 0xFFFFFF listed as SHOULD? If there is a case where the condition is satisfied by the listed value isn’t reported, then this needs to be documented; otherwise the draft ought to say MUST instead.
> 
> [Qin]: Accepted, we will use MUST.
> 
> - Section 3.3 reads as-if some new metrics are going to be defined, but all it actually does is reference another draft. I wonder if those summary metrics shouldn’t be defined in this draft, and if the split of related metrics into a separate draft is worthwhile in this case?
> 
> [Qin]: Okay, it looks no harm to remove section 3.3.


My question was actually whether it would make sense to split the summary metrics draft, and move some of that content into Section 3.3 of this draft.

[Qin]: I see your point, sorry for misunderstanding your intent.
I propose the following changes to sectioin 3.3 by moving some text from summary metrics draft as follows:
OLD TEXT:
"
3.3.  Derived metrics based on reported metrics

   The metrics described here are intended to be used in conjunction
   with information from the Measurement Information block [RFC6776],
   discard block [DISCARD] (which MUST be present in the same RTCP
   packet as the Burst/Gap Discard block).

   These metrics provides the following information relevant to
   statistical parameters, including:

   o  The fraction of packets discarded during bursts (burst discard
      rate in [SUMSTAT])

   o  The fraction of packets discarded during gaps (gap discard rate in
      [SUMSTAT])

   The details on calculation these parameters in the metrics are
   described in [SUMSTAT].
"
NEW TEXT:
"
3.3.  Derived metrics based on reported metrics

 

   The metrics described here are intended to be used in conjunction

   with information from the Measurement Information block [RFC6776] 

  (which MUST be present in the same RTCP packet as the Burst/Gap 

   Discard block) and also with the metric "number of packets discarded"

   provided in the RTCP XR Discard Count Block [DISCARD]. The RTCP XR 

   Discard Count Block SHOULD be sent if the Burst/Gap Discard block is

   sent, but the converse does not apply.

 

   These metrics provides the following information relevant to

   statistical parameters, including:

 

   o  The fraction of packets discarded during bursts (burst discard

      rate in [SUMSTAT]),which can be calculated using the metric  

      " Packets Discarded in Bursts " and the metric " Total Packets expected in Bursts " provided in Burst/Gap Discard metrics block.

 

 

   o  The fraction of packets discarded during gaps (gap discard rate in

      [SUMSTAT]) ,which can be calculated using the metric  

     " Packets Discarded in Bursts " and the metric " Total Packets expected in Bursts " provided in Burst/Gap Discard metrics block.

 

   The details on calculation these parameters in the metrics are

   described in [SUMSTAT].

"

-- 
Colin Perkins
http://csperkins.org/