IETF Logo Mail Archive

Re: [Anima] [dnssd] DNS-SD TXT question (for ANIMA use).

Stuart Cheshire <cheshire@apple.com> Tue, 03 May 2022 18:50 UTC

Return-Path: <cheshire@apple.com>
X-Original-To: anima@ietfa.amsl.com
Delivered-To: anima@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E115FC157B5B; Tue, 3 May 2022 11:50:22 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.672
X-Spam-Level:
X-Spam-Status: No, score=-2.672 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.575, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=apple.com
Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HfYiez6K7KPP; Tue, 3 May 2022 11:50:18 -0700 (PDT)
Received: from ma1-aaemail-dr-lapp03.apple.com (ma1-aaemail-dr-lapp03.apple.com [17.171.2.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A7A68C157B52; Tue, 3 May 2022 11:50:18 -0700 (PDT)
Received: from pps.filterd (ma1-aaemail-dr-lapp03.apple.com [127.0.0.1]) by ma1-aaemail-dr-lapp03.apple.com (8.16.0.42/8.16.0.42) with SMTP id 243InfuU050567; Tue, 3 May 2022 11:50:13 -0700
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=apple.com; h=content-type : mime-version : subject : from : in-reply-to : date : cc : content-transfer-encoding : message-id : references : to; s=20180706; bh=Ur+dQAcmDUBVB9/OJXgGasnWzQQuH9mpaEhltpHs8Zk=; b=tBIHOQpYf1Xxf3HTAjiRZJat64slop8I6zoIUTMIcDo+ccsGo3kPFJyrrNTE9OnqlD8R RGn3asOUZwqbE2enm5OhLSw8B0csQFwOW9d4pzlcxNgtqpxwxdIlypfSJJ3Ge6ON4KDw Q8ZGa5QrsvkDxv5RolXbprrMvVr4B6osBkGeDDdJPy7j45v10rewfAbu2htWcteru6eH bWMw7TmkPqTeXDdhmzU0l79LiligkjLL/OIbLt4RYebiU0Sb8Vryo3Fd3DIjXPAYkK6R gyOYHuxpY5vOYXX4zH0UeomjtlENKX9a6pSrjyey9OjwTfYT5trL4EWzMqyEsEYnZ4hX 9w==
Received: from rn-mailsvcp-mta-lapp02.rno.apple.com (rn-mailsvcp-mta-lapp02.rno.apple.com [10.225.203.150]) by ma1-aaemail-dr-lapp03.apple.com with ESMTP id 3fs43uyjav-12 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Tue, 03 May 2022 11:50:13 -0700
Received: from rn-mailsvcp-mmp-lapp03.rno.apple.com (rn-mailsvcp-mmp-lapp03.rno.apple.com [17.179.253.16]) by rn-mailsvcp-mta-lapp02.rno.apple.com (Oracle Communications Messaging Server 8.1.0.18.20220407 64bit (built Apr 7 2022)) with ESMTPS id <0RBB00MF0LNOM8K0@rn-mailsvcp-mta-lapp02.rno.apple.com>; Tue, 03 May 2022 11:50:12 -0700 (PDT)
Received: from process_milters-daemon.rn-mailsvcp-mmp-lapp03.rno.apple.com by rn-mailsvcp-mmp-lapp03.rno.apple.com (Oracle Communications Messaging Server 8.1.0.16.20220118 64bit (built Jan 18 2022)) id <0RBB00Z00LHDI100@rn-mailsvcp-mmp-lapp03.rno.apple.com>; Tue, 03 May 2022 11:50:11 -0700 (PDT)
X-Va-A:
X-Va-T-CD: f531f8d8b46e434c6cc260b03cd4b544
X-Va-E-CD: 5e8a9f335c3c252345ab9eb67f3b376b
X-Va-R-CD: 223e1706eefc6a455ebae3f65b4dc5f0
X-Va-CD: 0
X-Va-ID: 6cced8ce-b610-4b62-bc4b-09c7a4ac5bb2
X-V-A:
X-V-T-CD: f531f8d8b46e434c6cc260b03cd4b544
X-V-E-CD: 5e8a9f335c3c252345ab9eb67f3b376b
X-V-R-CD: 223e1706eefc6a455ebae3f65b4dc5f0
X-V-CD: 0
X-V-ID: 4c56b2b3-c250-4a94-836d-56bec62d5434
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.486, 18.0.858 definitions=2022-05-03_08:2022-05-02, 2022-05-03 signatures=0
Received: from [17.11.99.7] (unknown [17.11.99.7]) by rn-mailsvcp-mmp-lapp03.rno.apple.com (Oracle Communications Messaging Server 8.1.0.16.20220118 64bit (built Jan 18 2022)) with ESMTPSA id <0RBB00431LNMZF00@rn-mailsvcp-mmp-lapp03.rno.apple.com>; Tue, 03 May 2022 11:50:11 -0700 (PDT)
Content-type: text/plain; charset="utf-8"
MIME-version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.7\))
From: Stuart Cheshire <cheshire@apple.com>
In-reply-to: <YnFyCwHUSu67Uio7@faui48e.informatik.uni-erlangen.de>
Date: Tue, 03 May 2022 11:50:10 -0700
Cc: "touch@strayalpha.com" <touch@strayalpha.com>, dnssd@ietf.org, anima@ietf.org
Content-transfer-encoding: quoted-printable
Message-id: <97BE76F7-FA1B-4693-B410-4314C4F56964@apple.com>
References: <Ym6j/8qhEzvqNw2V@faui48e.informatik.uni-erlangen.de> <BECA0397-5B8B-4DAB-8706-D5727F86F73A@strayalpha.com> <YnFyCwHUSu67Uio7@faui48e.informatik.uni-erlangen.de>
To: Toerless Eckert <tte@cs.fau.de>
X-Mailer: Apple Mail (2.3608.120.23.2.7)
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.486, 18.0.858 definitions=2022-05-03_08:2022-05-02, 2022-05-03 signatures=0
Archived-At: <https://mailarchive.ietf.org/arch/msg/anima/t2gYgzt0_e0Q0Cqcx0fvAgh_zQM>
Subject: Re: [Anima] [dnssd] DNS-SD TXT question (for ANIMA use).
X-BeenThere: anima@ietf.org
X-Mailman-Version: 2.1.34
Precedence: list
List-Id: Autonomic Networking Integrated Model and Approach <anima.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/anima>, <mailto:anima-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/anima/>
List-Post: <mailto:anima@ietf.org>
List-Help: <mailto:anima-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/anima>, <mailto:anima-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 03 May 2022 18:50:23 -0000

On 3 May 2022, at 11:18, Toerless Eckert <tte@cs.fau.de> wrote:

> Thanks Joe, for reconfirming
> 
> Couldn't find any of those service names you listed to point to an RFC, so
> i gave up trying to find documentation of the exact formatting.
> 
> If a single service instance (IP-addr/port) can support let's say more
> than one protocol (variation), then i guess we have to come up with
> our own encoding proposal, as there is no standard ?!
> 
>  eg: proto=variation1,variation2,...
> 
>  (catenate protocols with ",").

Maybe follow the example set by IPP, where it lists supported print description languages:

pdl=application/octet-stream,application/pdf,application/postscript,image/jpeg,image/png,image/urf

See <http://www.dns-sd.org/ServerStaticSetup.html#AirPrint>

> I guess this could happen when we come up with different
> protocols all running on top of coap (given how the service instance
> port number is only bound to the coap layer).

That would be a bad design.

The service type says what a service does, not what engineering decisions were made in its design.

Advertising a “CoAP” service makes as much sense as advertising a service type called “ascii” or “utf-8” or “xml” just because the protocol happens to use those things.

See <https://datatracker.ietf.org/doc/html/rfc6763#section-7>

Particularly read the part that says, “Wise selection of a Service Name is important...”

Stuart Cheshire

v2.23.0 | Report a Bug | By Email