[core] Re: [IANA #1421776] expert review for draft-ietf-core-dns-over-coap (dns-svcb)

[Ben Schwartz <[e-mail]>]

Separate from IANA review, I see that this draft notes its primary justification as

   Note that this specification is distinct from DoH, since the CoAP-
   specific FETCH method [RFC8132] is used.

However, in the time since this draft was developed, the HTTP working group has advanced a new document on a similar method named QUERY: https://datatracker.ietf.org/doc/draft-ietf-httpbis-safe-method-w-body/

It seems like this could be an opportunity to reduce divergence between CoAP and HTTP, by adopting the same method or defining an equivalence.

--Ben
________________________________
From: Ben Schwartz <[e-mail]>
Sent: Tuesday, June 24, 2025 2:07 PM
To: [e-mail] <[e-mail]>
Cc: Ben Schwartz <[e-mail]>; [e-mail] <[e-mail]>; [e-mail] <[e-mail]>
Subject: Re: [IANA #1421776] expert review for draft-ietf-core-dns-over-coap (dns-svcb)

The document doesn't provide any examples of valid "docpath" values, which makes it difficult for me to assess whether the proposed encoding raises any compatibility concerns.  Please add some examples to enable appropriate review.  Suggested examples:

* Single text string
* Multiple text strings
* Coexistence with "dohpath" (assuming this is permitted)

I note that the text permits a "docpath" key with zero text strings, but does not explain the semantic distinction, if any, between this empty value and not having a "docpath" key.  Please indicate whether these are equivalent, and consider prohibiting one option if they are redundant.

This document appears to be a "SVCB mapping document" for the scheme "coaps://", as defined in RFC 9460 (https://datatracker.ietf.org/doc/html/rfc9460#section-2.4.3-2)  RFC 9460 imposes certain requirements on mapping documents (e.g. https://datatracker.ietf.org/doc/html/rfc9460#section-7-2, https://datatracker.ietf.org/doc/html/rfc9460#section-12-5)  This draft goes perhaps too far in restating/conflicting with certain aspects of RFC 9460's client behavior, while also omitting some information that would be helpful, such as a protocol mapping summary table (e.g. https://datatracker.ietf.org/doc/html/rfc9460#name-http-mapping-summary)

--Ben
________________________________
From: David Dong via RT <[e-mail]>
Sent: Tuesday, June 24, 2025 12:58 PM
Cc: Ben Schwartz <[e-mail]>; [e-mail] <[e-mail]>; [e-mail] <[e-mail]>
Subject: [IANA #1421776] expert review for draft-ietf-core-dns-over-coap (dns-svcb)

Dear Benjamin Schwartz, David Lawrence (cc: core wg),

As the designated experts for the DNS SVCB Service Parameter Keys (SvcParamKeys) registry, can you review the proposed registration in draft-ietf-core-dns-over-coap-15 for us? Please see

https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-ietf-core-dns-over-coap/__;!!Bt8RZUm9aw!6sTnGvRry246XL0EMIo9hVbTxG9iAbsJ92KxUO9-Th-teFjCrCOaoaNrdg2zlZo2tfa4cxleIp4ra9Nil09OnA$

The due date is July 8th.

If this is OK, when the IESG approves the document for publication, we'll make the registration at:

https://urldefense.com/v3/__https://www.iana.org/assignments/dns-svcb/__;!!Bt8RZUm9aw!6sTnGvRry246XL0EMIo9hVbTxG9iAbsJ92KxUO9-Th-teFjCrCOaoaNrdg2zlZo2tfa4cxleIp4ra9PyaleOoQ$

Unless you ask us to wait for the other reviewer, we’ll act on the first response we receive.

With thanks,

David Dong
IANA Services Sr. Specialist