Subject: [MMUSIC] AD Evaluation of draft-ietf-mmusic-sctp-sdp-21

From: "Ben Campbell" <[email-masked]>
Date: Fri, 20 Jan 2017 16:01:49 -0600

Hi,

This is my AD Evaluation of draft-ietf-mmusic-sctp-sdp-21. The draft is 
mostly in good shape, but I would like to at least discuss the 
substantive comments prior to IETF last call.

Thanks!

Ben.

----------------
Substantive Comments

-1, first paragraph: RFC 5572-update is currently in IETF LC. Is there a 
reason not to reference it instead?

-4.1, last paragraph:
I assume this paragraph refers to fmt values used with UDP/DTLS/SCTP or 
TCP/DTLS/SCTP, not fmt values in general. It would help to be explicit 
about that. (Also, it seem like this paragraph belongs in section 4.3).

-4.5: The example is missing the sctp-port attribute.

-5.3: Why is the mux-category SPECIAL rather than CAUTION? IIUC, SPECIAL 
means you need to refer to the rules in the protocol definition. But the 
text here basically say that the rules are undefined.

-6.1: What is meant by saying an "endpoint MUST assume that larger ... 
will be rejected"? Can that be stated in terms of actual procedure (e.g. 
"endpoint MUST NOT send...larger"?

-6.2, "Purpose" field: Please include the unit here, too.

-9.1, 2nd paragraph: Don't the lower layers need to be established 
before the upper layers? Won't removal of the TCP connection or DTLS 
association break an existing SCTP association?

-18.2: Seems like RFC0793 and RFC6544 should be normative references.

Editorial Comments:

-1, 2nd paragraph: Seems like SCTP is also used to transport data :-)

-1, last paragraph: is "strongly RECOMMENDED" intended to be stronger 
than RECOMMENDED? Assuming you don't mean MUST, please consider dropping 
the adverb.

-6.1, typo: thevmaximum

-9.1, 2nd paragraph: s/mange/manage

-9.3, last paragraph: What does "impact" mean in context? Change state? 
(It seems like these actions would likely cause data to be sent at the 
SCTP layer, which seems like a kind of impact.)

-10.3: Does "identical" mean identical to that from the offer?

-10.3, 8th paragraph: s/"closing establishing"/"closing or establishing"