Re: [Uri-review] Request for URI schemes assigned to OPC UA

On Tue, May 23, 2017 at 9:03 AM, Randy Armstrong <
randy.armstrong@opcfoundation.org> wrote:

> The URN conforms  to:
>
> https://tools.ietf.org/html/rfc2141
>
>
> Other than that the specification leaves it up to the implementer to
> choose something globally unique.
>
>
RFC 3406, recently replaced by RFC 8141 go into the mechanics of URN
registration.  Briefly, global uniqueness of the NID is maintained by a
global registry or URN namespace identifiers.

> Implementers also have the option of using the http scheme as the
> application URI.
>
Is there a reason to register a URN scheme when we don't care about the
> content of the URN?
> ------------------------------
>

I understood your message below indicated that the URN was the canonical
name for the resources, with the individual network paths being linked to
that URN.  Did I get that wrong?

regards,

Ted

> *From:* Ted Hardie <ted.ietf@gmail.com>
> *Sent:* Tuesday, May 23, 2017 8:34:50 AM
> *To:* Randy Armstrong
> *Cc:* Graham Klyne; uri-review@ietf.org; TCB
>
> *Subject:* Re: [Uri-review] Request for URI schemes assigned to OPC UA
>
> On Tue, May 23, 2017 at 5:30 AM, Randy Armstrong <randy.armstrong@
> opcfoundation.org> wrote:
>
>> 1) We use the schemes for URLs that identify multiple network paths to a
>> single resource which is identified with a URI that uses the 'urn' scheme.
>> It is not clear to me that registration is required for this usage. Please
>> advise.
>>
>>
>> Would you mind identify which URN nid you are using?  I did not see one
> listed here:
>
> https://www.iana.org/assignments/urn-namespaces/urn-namespaces.xhtml#urn-
> namespaces-1
>
> that was obvious.
>
> regards,
>
> Ted
>
>
>
>> 2) The specs is an IEC specification as well (see
>> https://webstore.iec.ch/publication/21993 ). In addition, the text
>> quoted is old. Anyone can download the specifications from the OPC
>> Foundation website today.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------
>> *From:* Graham Klyne <gk@ninebynine.org>
>> *Sent:* Tuesday, May 23, 2017 2:07:11 AM
>> *To:* Randy Armstrong; uri-review@ietf.org
>> *Cc:* TCB
>> *Subject:* Re: [Uri-review] Request for URI schemes assigned to OPC UA
>>
>> I have two objections here to permanent registration:
>>
>> 1. The specifications appear to be non-open "Note: Access to
>> specifications and
>> developer resources are available to OPC Foundation members only."
>>
>> 2. The use of multiple URI schemes to access the same resource goes
>> against
>> principles of web architecture [http://www.w3.org/TR/webarch/#uri-aliases
>> ].
>>
>> This topic has been discussed previously on this list: see thread at [1].
>>
>> [1]
>> https://mailarchive.ietf.org/arch/search/?email_list=uri-rev
>> iew&gbt=1&index=ze2I30iloSGZxlP2vAeCWcPOWus
>>
>> #g
>> --
>>
>>
>>
>> On 22/05/2017 22:04, Randy Armstrong wrote:
>> > Scheme name:
>> >
>> > opc.tcp       :  OPC UA Connection Protocol over TCP/IP
>> > opc.amqp  :  OPC UA Connection Protocol over AMQP
>> > opc.wss      :  OPC UA Connection Protocol over WebSockets
>> >
>> > We expect to add new schemes as time goes on.
>> >
>> > Status:  permanent
>> >
>> > Applications/protocols that use this scheme name:
>> >
>> > Applications which implement the OPC UA Connection Protocol defined by
>> the OPC Unified Architecture specification:
>> > https://opcfoundation.org/developer-tools/specifications-
>> unified-architecture
>> >
>> > The opc.tcp scheme has been in use in the field for about 10 years (we
>> were unaware of the registration process).
>> > Note that the OPC Foundation has a trademark on the term "OPC" (see US
>> Trademark #78732560)
>> >
>> > Contact:
>> > Randy Armstrong
>> > tcb@opcfoundation.org
>> >
>> > Change controller:
>> > OPC Foundation
>> > https://opcfoundation.org/
>> >
>> > References:
>> > The protocols and schemes are defined in Part 6: Mappings:
>> > http://www.opcfoundation.org/UA/Part6/
>> >
>> > _______________________________________________
>> > Uri-review mailing list
>> > Uri-review@ietf.org
>> > https://www.ietf.org/mailman/listinfo/uri-review
>> >
>>
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>