Timezone Options for DHCP
draft-ietf-dhc-timezone-option-05

[Ballot comment]
Some wording about the approriateness of using timezone configuration in the mobile case might be useful.

Editorial:

In abstract:

This memo specifies DHCP options each of those methods.

I presume it was supposed to read as:

This memo specifies DHCP options for each of those methods.

IANA Last Call Comments:

Upon approval of this document, the IANA will make three
changes to the registries that support DHCP:

First, in the registry located at:
http://www.iana.org/assignments/bootp-dhcp-parameters
in the subregistry named, BOOTP Vendor Extensions and DHCP
Options, two new values will be added:

Data
Tag Name Length Meaning
--- ---- ------ -------
TBD PCode N IEEE 1003.1 String
TBD TCode N Reference to the TZ Database

Second, in the registry located at:
http://www.iana.org/assignments/bootp-dhcp-parameters
in the subregistry named, BOOTP Vendor Extensions and
DHCP Options, option 2 will be changed from:

Data
Tag Name Length Meaning
--- ---- ------ -------
2 Time Offset 4 Time Offset in
Seconds from UTC

to the following:

Data
Tag Name Length Meaning
--- ---- ------ -------
2 Time Offset 4 Time Offset in
Seconds from UTC (note: deprecated by
TBA and TBA; see )

With reference changed to reflect the approved document.

Third, in the registry located at:
http://www.iana.org/assignments/dhcpv6-parameters
in the subregistry titled, DHCP Option Codes, two
new values will be added:

Value Description
----- ----------------------
TBD OPTION_NEW_POSIX_TIMEZONE
TBD OPTION_NEW_TZDB_TIMEZONE

We understand the above to be the only IANA Actions
for this document.

[Ballot discuss]
In the document, a reference is given to http://www.twinsun.com/tz/tz-link.htm and the associated time zone database linked from there, but there is no clear statement of what
from the linked database field is in the TCODE field.  Here is the first statement:

TCode  Len  TZ-Database String
          +-----+-----+------------------------------+
          | TBD |  N  | Reference to the TZ Database |
          +-----+-----+------------------------------+

and here is a second statement:

0                  1                  2                  3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  OPTION_NEW_TZDB_TIMEZONE    |          option-length        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          TZ Name                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


Here is an example entry from the TZ database:

# Switzerland
# From Howse:
# By the end of the 18th century clocks and watches became commonplace
# and their performance improved enormously.  Communities began to keep
# mean time in preference to apparent time -- Geneva from 1780 ....
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# From Whitman (who writes ``Midnight?''):
Rule Swiss 1940 only - Nov 2 0:00 1:00 S
Rule Swiss 1940 only - Dec 31 0:00 0 -
# From Shanks & Pottenger:
Rule Swiss 1941 1942 - May Sun>=1 2:00 1:00 S
Rule Swiss 1941 1942 - Oct Sun>=1 0:00 0 -
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Europe/Zurich 0:34:08 - LMT 1848 Sep 12
0:29:44 - BMT 1894 Jun # Bern Mean Time
1:00 Swiss CE%sT 1981
1:00 EU CE%sT


From the example string and the TZ Name, I conclude that the NAME field is
what is desired.  But I believe that the document should be very clear about that.
I would suggest including the full TZ database entry for the example string given
(Europe/Zurich), as well as stating carefully that the NAME field is expected.

Requested help from APPS ADs, Thomas Narten, and Mark Townsley for finding an "owner"/reviewer for this work so that we can make sure it makes sense not just from DHCP but also from the functionality point of view.

Publication requested by DHC chairs. However, given the dhc-dnsdomain experience, the chairs and AD are considering performing additional review before this is really handed off from the DHC WG.