[AVTCORE] Comments coming out of the Shepherds writeup: draft-ietf-avtcore-leap-second-05

Magnus Westerlund <magnus.westerlund@ericsson.com> Wed, 30 October 2013 16:01 UTC

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Date: Wed, 30 Oct 2013 17:01:45 +0100
From: Magnus Westerlund <magnus.westerlund@ericsson.com>
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Subject: [AVTCORE] Comments coming out of the Shepherds writeup: draft-ietf-avtcore-leap-second-05
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Hi Kevin and Ray,

I have some few things I like to fix before requesting publication.
Sorry for not doing my writeup earlier and spotting this earlier.

1. Section 9.2

The following references are a bit thin on information.

   [9]        IEEE, "IEEE Standard for a Precision Clock Synchronization
              Protocol for Networked Measurement and Control Systems",
              July 2008.

   [10]       Global Positioning Systems Directorate, "Navstar GPS Space
              Segment/Navigation User Segment Interfaces", September

   [11]       BIPM, "Circular T", May 2012.

For example 9 is not stating that this is 1588.

Both 10 and 11 could benefit from a link.

[11] should have BIPM expanded.

Circular T appears to be a monthly publication of correction/correlation
data. What is the intention with this reference?
To use the appropriate or the latest? Or was May 2012 the right one?

Is this an issue of getting the XML to include what is included in

2. Section 5:

Note that a working
   communication channel includes a protocol means of notifying clocks
   of an impending leap second such as the Leap Indicator in the NTP
   header [8] but also a means for top-tier clocks to receive leap-
   second schedule information published by the International Earth
   Rotation and Reference Systems Service.

I think there should be a informative reference to "International Earth
   Rotation and Reference Systems Service" with an URL, or at least
include the URL in the text.

3. Section 5:
   RTP implementation using a wall-clock reference is simplified by
   using a clock with a timescale which does not include leap seconds.
   IEEE 1588,[9] GPS [10] and other TAI [11] references do not include
   leap seconds.

Is really [11] a good informative reference what TAI is?

Can you please prepare an update of these issues and submit when the ID
submission opens on Monday so that I can request publication?


Magnus Westerlund

Multimedia Technologies, Ericsson Research EAB/TVM
Ericsson AB                | Phone  +46 10 7148287
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