I am the assigned Gen-ART reviewer for this draft. For background on
Gen-ART, please see the FAQ at
<http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
Please resolve these comments along with any other Last Call comments
you may receive.
Document: draft-ietf-xrblock-rtcp-xr-psi-decodability-04
Reviewer: Tom Taylor
Review Date: 6 July 2014
IETF LC End Date: 7 July 2014
IESG Telechat date: (not known)
Summary: basically ready with very minor issues and a number of
editorial suggestions.
Major issues: none.
Minor issues:
(1) It might be helpful to add text in Section 3 explaining that
PAT_error_2_count and PMT_error_2_count are actually replacements for
and improvements on PAT_error_count and PMT_error_count respectively and
are therefore preferred in future implementations.
(2) Condition (2) of PAT_error_2_count: "one table with table_id other
than 0x00" is more precise than intended by [ETSI]. s/one/a/. This
comment also applies to PMT_error_2_count (third from last line of first
paragraph) and CAT_error_count (both conditions).
Nits/editorial comments:
General: blanks are missing in a number of places, typically following a
comma or preceding a parenthesis.
Abstract
--------
"statistics metrics" seems a bit redundant, but I wonder if "metric"
has a special meaning to people working in this area. To me, "metric" is
another word for "measurement result". So its use to describe the
contents of the XR block makes sense. However, when we get to Section 3,
"metric" is used in place of "indicator". Is that really correct usage?
s/Program specific information/Program Specific Information/
Section 1.1
-----------
Some redundancy with the opening paragraph of 1.1, some cramming
together of different ideas. Suggested alternative:
OLD
This memo is based on information consistency tests and resulting
indicators defined by ETSI [ETSI] and defines a new block type to
augment those defined in [RFC3611] for use with MPEG2 Transport
Stream (TS) [ISO-IEC.13818-1.2007]. The new block type supports
reporting of the number of occurrences of each Program Specific
Information (PSI) indicator in the first and second priorities that
supplements information from PSI independent Decodability Statistics
Metrics Block [RFC6990]; third priority indicators are not supported.
NEW
This memo defines a new block type for use with MPEG2 Transport
Stream (TS) [ISO-IEC.13818-1.2007], to
augment those defined in [RFC3611]. The new block type supports
reporting of the number of occurrences of each Program Specific
Information (PSI) indicator in the first and second priorities listed
by [ETSI] sections 5.2.1 and 5.2.2 respectively. Third priority
indicators are not supported. The metrics defined here
supplement information from the PSI-independent Decodability
Statistics Metrics Block [RFC6990].
Section 1.2
-----------
s/defined/defines/ on second line for consistency with the other sentences.
Section 1.3
-----------
s/Architectures [RFC6792]/Architecture [RFC6792]/
s/guideline/guidelines/
s/for reporting block format using RTCP XR/for RTCP XR reporting block
formats/
Section 1.4
-----------
s/;/,/ on second line.
s/;/./ on third-last line.
Section 3
---------
See remark on use of "metric" above (Section 1.1). Could the first
sentence be rewritten:
OLD
ETSI TR 101290 [ETSI] generally defines metrics related to error
events while this document contains counts of those metrics defined
in [ETSI].
NEW
ETSI TR 101290 [ETSI] generally defines indicators related to error
events, while the XR block defined in this document contains counts
of occurrences of the [ETSI] indicators.
Fifth line: s/PSI independent/PSI-independent/ (add hyphen)
Paragraph below the CRC and CAT bullets:
(1) What do you mean by: "scrambling may be considered"? Do you mean
that the presence or absence of scrambling is part of the error
checking, or something else?
(2) I'd suggest expanding "The other parameters ..." to "The other
parameters defined in [ETSI] Section 5 [or whatever scope you intended]
but not listed above ...".
Section 3, PID_Error_Count
--------------------------
Second sentence is not quite accurate. It should read:
OLD
A PID_error occurs when MPEG TS streams
are remultiplexed and any PID doesn't refer to an actual data
stream, as defined in the section 5.2.1 of [ETSI]
NEW
A PID error occurs [is indicated?] when no data stream is present
corresponding to a given PID. This may be caused by multiplexing
or demultiplexing, then remultiplexing. See
section 5.2.1 of [ETSI].