Hi,
On Thu, Jan 9, 2014 at 7:47 AM, SM <sm(_at_)resistor(_dot_)net> wrote:
Hi Juergen,
At 02:58 09-01-2014, Juergen Schoenwaelder wrote:
People want to be able to configure timezones using the timezone
naming scheme commonly supported by operating systems (e.g.,
Europe/Paris). This document defines a serialization of the timezone
names into YANG format for this purpose. I believe there was indeed
strong concensus on this in the WG.
There was a message about a quick poll [1] to adopt
draft-lange-netmod-iana-timezones-01 on 2 July, 2012. Three persons
expressed their support and the WG Chair expressed his support as a
technical contributor [2]; there weren't any message objecting to adoption.
There were two comments [3][4] on 30 July, 2012. There was a WG Last Call
announcement [5] and two reminders [6][7] about it. There was a message [8]
on 12 November, 2013 from a WG participant (I am not taking into account
the message from the author and one of the WG Chairs). My comment about
the determination of consensus being questionable is based on the messages
in the NETMOD mailing list archive.
This document aims at establishing an IANA maintained serialization of
whatever list of names the timezone database contains. It does not
change the way the TZ coordinator, an IANA Designated Expert, takes
decisions. Perhaps this needs to be stated more explicit.
There is a thread at http://mm.icann.org/pipermail/tz/2012-May/017711.html
The problem is not changing the way things are done. I would describe the
current TZ approach as keeping the TZ information up-to-date by posting a
(software) release every now and then. It works for me.
So far (in the MIB world), the initial versions of IANA maintained
modules were published as Proposed Standards on the standards track
(although the only thing that really remains valid over time are the
IANA considerations, which however often require the initial module to
be available). We simply followed this practice.
If I understood correctly the YANG module defined in the draft creates
IANA-registered timezones based on public domain [9] information about
timezones. IANA is then asked to keep the IANA-registered timezones
up-to-date. That sounds okay if the politics about time are not taken into
consideration [10][11][12].
There was concensus in the WG that it is desirable to configure
timezones by name (e.g., Europe/Paris) instead of having only hard
coded UTC offsets - the benefits should be obvious.
I agree that there can be benefits to that approach. I could not find the
(mailing list) message where that WG decision was taken.
After reading the IANA Considerations section closer, I have some concerns
about the use of a YANG enumeration. This section does not say who must
update the enumeration typedef and republish the RFC containing the new
YANG module, every time the TZ database is changed.
Is it the NETMOD WG? IANA?
This may not be a practical long-term solution.
The purpose of a YANG enumeration type is to allow a well-constrained
value set that can be machine-validated. If the data type was a string
instead of an enumeration, there would be no IANA coupling or republishing
(or YANG-based machine validation). The description-stmt can say a leaf
using this data type MUST match a value in the TZ database.
The draft (sec. 3.1) also says to change the status of the old enum to
obsolete
and add a new enum, in order to change the name. YANG definitions are
supposed to transition from current to deprecated, not current to obsolete.
Regards,
-sm
Andy
1. http://www.ietf.org/mail-archive/web/netmod/current/msg06810.html
2. http://www.ietf.org/mail-archive/web/netmod/current/msg06841.html
3. http://www.ietf.org/mail-archive/web/netmod/current/msg06932.html
4. http://www.ietf.org/mail-archive/web/netmod/current/msg06933.html
5. http://www.ietf.org/mail-archive/web/netmod/current/msg08327.html
6. http://www.ietf.org/mail-archive/web/netmod/current/msg08333.html
7. http://www.ietf.org/mail-archive/web/netmod/current/msg08335.html
8. http://www.ietf.org/mail-archive/web/netmod/current/msg08694.html
9. ftp://ftp.iana.org/tz/tz-link.html
10. http://www.theguardian.com/news/datablog/2013/sep/26/
spain-countries-wrong-time-zone
11. http://972mag.com/the-worlds-only-ethnic-time-zone/81006/
12. http://www.theblaze.com/stories/2013/09/22/just-wait-
until-you-see-how-apples-new-operating-system-lists-jerusalem/