Re: [MMUSIC] Review of draft-ietf-mmusic-dtls-sdp-22

"Carlos Pignataro (cpignata)" <cpignata@cisco.com> Thu, 30 March 2017 16:13 UTC

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From: "Carlos Pignataro (cpignata)" <cpignata@cisco.com>
To: Christer Holmberg <christer.holmberg@ericsson.com>
CC: "draft-ietf-mmusic-dtls-sdp.all@ietf.org" <draft-ietf-mmusic-dtls-sdp.all@ietf.org>, "ietf@ietf.org" <ietf@ietf.org>, "mmusic@ietf.org" <mmusic@ietf.org>
Thread-Topic: Review of draft-ietf-mmusic-dtls-sdp-22
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Date: Thu, 30 Mar 2017 16:13:35 +0000
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Subject: Re: [MMUSIC] Review of draft-ietf-mmusic-dtls-sdp-22
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Hi, Christer,

> On Mar 28, 2017, at 12:00 PM, Christer Holmberg <christer.holmberg@ericsson.com> wrote:
> 
> Hi Carlos,
> 
> Thanks for your review! Please see inline.

Anytime — thanks for the follow-up!

> 
>> Reviewer: Carlos Pignataro
>> Review result: Has Nits
>> 
>> This document is very comprehensive. Operational Considerations are
>> adequately covered.
>> 
>> In reviewing this document, I did find two adjacent issues that I
>> thought useful to comment on:
>> 
>> 1. Clarity and Readability of Section 9
>> 
>> I appreciate the explicit OLD/NEW details and specifics on what is
>> changed on the updated RFCs. I wish more documents would do this!
>> 
>> However, the way in which this is done is very confusing and not
>> really optimizing clarity and readability. It is an operational issue
>> an implementor not understanding the spec :-)
>> 
>> The issue, in my view, is with the labels and markers. Subsections of
>> Section 9.2 do not follow the semantic structure of the document.
>> Instead they are included as follows:
>> "
>> Update to section 5:
>> --------------------
>> "
>> Which are then followed by OLD/NEW chunks. However, these chunks:
>> * include Section numbers and titles, 
>> * do not have extra indentation, and
>> * include only BEGIN marker but not END marker.
>> 
>> Like:
>> 
>> 9.2.  Update to RFC 5763
>> Update to section 5:
>> --------------------
>> OLD TEXT:
>> 5.  Establishing a Secure Channel
>> 
>> [... and then, two pages later ...]
>> 
>> NEW TEXT:
>> 5.  Establishing a Secure Channel
>> 
>> I'd suggest:
>> a. Using Section 9.2.1, 9.2.2, etc. for each change.
> 
> I can put each section change in a separate section.
> 
> 9.2.1 Update to section 5
> 9.2.2 Update to section 6.6
> ...
> 
> Or, do you want to have the old and new text in different sections too? Personally I would like to keep the old and new text in the same section.

I agree. Having a section for each change chunk (OLD/NEW) seems most clean and clear.

> 
>> b. Use more explicit chunk demarkators
> 
> It was been suggested to use "|". 
> 
>> c. Use beginning and ending markers.
> 
> [BEGIN]
> Blah blah blah...
> [END]
> 
> ----------

Thank you — any format that you feel will add clarity. Right now it was a bit challenging to parse.

> 
>> 2. The second issue, and likely this was discussed, relates to the use
>> of RFC 4572. A reference to RFC 4572 is Normative, and it is cited
>> within "NEW" text (not only "OLD" text). However RFC 4572 has been
>> Obsoleted by RFC 8122!
>> 
>> This is because draft-ietf-mmusic-4572-update published as RFC 8122,
>> which should be updated. 
> 
> Correct. I will do that in the next version.

Ack. Thanks.

> 
>> But for example, why does NEW text here still points to RFC 4572?
> 
> The reason is probably that, initially draft-4572-update did not obsolete RFC 4572 - it simply updated it. But, later it was agreed that draft-4572-update will obsolete RFC 4572, but that was not reflected in draft-dtls-sdp.
> 
> So, you are correct, the new text shall point to RFC 8122. I will fix that in the next version.
> 

Perfect.

> ---------
> 
>> --->8---
>> NEW TEXT:
>> 
>> 5.  Establishing a Secure Channel
>> 
>>  The two endpoints in the exchange present their identities as part
>>  of the DTLS handshake procedure using certificates. This document
>>  uses certificates in the same style as described in "Connection-Oriented
>>  Media Transport over the Transport Layer Security (TLS) Protocol
>>  in the Session Description Protocol (SDP)" [RFC4572].
>> --->8---
>> 
>> And why RFC 4572 is Normatively referenced?
> 
> I will make the reference Informative.
> 

Looks good — thanks again,

— Carlos.

> Thanks!
> 
> Regards,
> 
> Christer
>