Re: [AVTCORE] AD review of draft-ietf-avtcore-multi-party-rtt-mix

Gunnar Hellström <> Thu, 08 April 2021 21:18 UTC

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To: "Murray S. Kucherawy" <>,
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Subject: Re: [AVTCORE] AD review of draft-ietf-avtcore-multi-party-rtt-mix
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Hello Murray,

Thanks for the review,

I have answered and acted on all but the SHOULD and RECOMMENDED etc. in 
sections 3.4 -4. The response on them will be provided soon.

See answers inline,

Den 2021-04-08 kl. 06:45, skrev Murray S. Kucherawy:
> Hello friends, sorry for the delay getting this review done.
> I think this is generally in good shape, though I admit my 
> understanding of WebRTC isn't as strong as I'd like.  My review is 
> therefore mostly about form rather than substance.
> At any rate, I have the following comments to offer after a first 
> review.  Please let me know what you think.
> --
> The Abstract is unusually long.  I would suggest reducing it to a 
> paragraph or two, or maybe three.  My lay opinion is that the first 
> two paragraphs could be left for the Introduction section, but other 
> approaches are also probably available.
[GH] Moved one paragraph to the intro, deleted another because it had 
similar wording in the intro.
> In many places, references look odd (e.g., "RFC3550[RFC3550]").  This 
> may be an artifact of the way the XML generates the text or HTML forms 
> but it might be worth a quick review to get it to look right.
> In Section 1.1, please use the new BCP 14 boilerplate (combining RFC 
> 2119 and RFC 8174).  Also in that section, "as defined in" should be 
> "are defined in".
> In Section 1.3, "where a calltaker want to take" should use "wants" 
> instead of "want".
> Is the "SHOULD" in Section 2.2 a piece of interoperability advice, or 
> is it advice about presentation?

[GH] Intended to be for interoperability.   I suggest to insert wording 
to result in:

SHOULD *in order to maintain interoperability,* if nothing else is 
specified for the application, format transmitted text to that 

> In Sections 2.4, 3.20, and 7, in multiple places, "sdp" should be in 
> all caps.
[GH] Done
> In Section 3.2, remove "being".

[GH] Would it be even more clear to replace "being" with "is" ?

    "As soon as a participant is known to participate in a session with
    another entity and is available for text reception, a Unicode BOM
    character SHALL be sent to it....."

> Section 3.4 has a bunch of "SHOULD" and "RECOMMENDED" that are not 
> explained.  See comment below about Section 8 for my thinking here.  
> This continues throughout the rest of Section 3's subsections and much 
> of Section 4.

[GH] For 3.4, the explanation is at the end of the section: "The 
intention is to keep the latency low and network load limited while 
keeping a good protection against text loss in bursty packet loss 

But that is a summary explanation. I can insert explanations for each 
timing figure in the section.

I stop handling this comment here for now and will return to it soon 
with another response..

> In Section 3.20, "this sections shows" should be "this section shows".
[GH] Done
> In Section 4.2.6, "these facts makes" should be "these facts make".
[GH] Done

> Section 8 has a bare "SHOULD", by which I mean advice is given with no 
> context.  "SHOULD" and "RECOMMENDED" present a choice; why might an 
> implementer legitimately decide not to follow this advice?  If there's 
> no good reason, should these be "SHALL"/"MUST" instead?
[GH] Agreed, in this case SHALL is right.
> Section 11, second paragraph: "restricted of privacy reasons" should 
> probably be "restricted for privacy reasons".
[GH] Done
> Section 11, third paragraph: "masquerading" should be "masquerade".
[GH] Done
> Section 11 should also probably refer to Section 3.19.
[GH] A reference added last in 11: "Further security considerations 
specific for this application are specified in section 3.19."
> Commonly, a "Changes" section (Section 12 here) is marked with a note 
> like:
>     [RFC Editor: Please remove this section prior to publication.]
> (At least I presume that's the intent for this section as well.)

[GH] Done



> -MSK
> _______________________________________________
> Audio/Video Transport Core Maintenance

Gunnar Hellström