Subject: [avtext] Eric Rescorla's No Objection on draft-ietf-avtext-lrr-06: (with COMMENT)

From: Eric Rescorla <[email-masked]>
Date: Mon, 19 Jun 2017 16:32:27 -0700

Eric Rescorla has entered the following ballot position for
draft-ietf-avtext-lrr-06: 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-avtext-lrr/

----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

 S 2.1.
   In a layer refresh, however, other layers than the ones requested for
   refresh may still maintain dependency on earlier content of the
   stream.  This is the difference between a layer refresh and a Full

This "however" is hard to read because the entire previous graf
talks about layer refreshes.

All the diagrams in this section would be a lot easier to read
if they said that <- means "refers to"

 S 3.1
   The Feedback Control Information (FCI) for the Layer Refresh Request
   consists of one or more FCI entries, the content of which is depicted
   in Figure 5.  The length of the LRR feedback message MUST be set to
   2+3*N, where N is the number of FCI entries.

You should state that the length is in 32-bit words.

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | RES     | TTID| TLID          | RES     | CTID| CLID (opt)    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

How is CLID optional? It seems like it still has to be there,
unless I am misreading the text.

   Reserved (RES) (16 bits / 5 bits / 5 bits)  All bits SHALL be set to
      0 by the sender and SHALL be ignored on reception.

I would mention that this is three fields.

---

From: Jonathan Lennox <[email-masked]>
Date: Thu, 29 Jun 2017 23:23:43 +0000

Hi, sorry for the delay in responding.  Responses inline.

> On Jun 19, 2017, at 7:32 PM, Eric Rescorla <[email-masked]> wrote:
> 

The “however” is meant to indicate that we’re contrasting the layer being refreshed with the other layers which aren't.  I’ve reworded as

	However, in a layer refresh, layers other than the ones …

(incorporating Warren’s comment as well).  Does that read better to you?

> if they said that <- means "refers to”

Okay.  I’ve added text to the figure preambles that says it indicates a coding dependency.

> You should state that the length is in 32-bit words.

Ok.

Its use / semantic is optional, but yes, syntactically it has to be there, so (opt) is confusing. Removed.

> I would mention that this is three fields.

Ok.

---

From: Eric Rescorla <[email-masked]>
Date: Thu, 29 Jun 2017 20:26:05 -0700

On Thu, Jun 29, 2017 at 4:23 PM, Jonathan Lennox <[email-masked]> wrote:

> The “however” is meant to indicate that we’re contrasting the layer being
> refreshed with the other layers which aren't.  I’ve reworded as
>

A bit....

-Ekr