Hi Barry, WG,
I saw the DISCUSS [1] in the datatracker but for some reason the email
never landed in my inbox or the list [2]. I am manually posting it
here -
====
Discuss (2019-09-16)
Thanks for another clear document. There are some "SHOULD" key words
in one section that I would like to discuss, and that I think we ought
to be able to resolve without much difficulty:
— Section 5.7 —
There are various “SHOULD”s in this section, and I have the same
comment about all of them: BCP 14 says, about “SHOULD”, that “there
may exist valid reasons in particular circumstances to ignore a
particular item, but the full implications must be understood and
carefully weighed before choosing a different course.” I see no
guidance here to help the reader understand what such circumstances
and implications are, so I can’t see how an implementer can evaluate
the situation. Can you provide any help here?
====
Comment (2019-09-16)
Again, these are purely editorial comments, which need no detailed
response; please just consider them.
— Section 1 —
Over time, based on the varying traffic pattern, an LSP established
with a certain bandwidth may require to adjust the bandwidth reserved
in the network dynamically.
“may require adjustment of the bandwidth”
This is similar to
the Passive stateful PCE model, while the Passive stateful PCE uses
path request/reply mechanism, the Active stateful PCE uses
report/update mechanism.
NEW
This is similar to
the Passive stateful PCE model: while the Passive stateful PCE uses
a path request/reply mechanism, the Active stateful PCE uses a
report/update mechanism.
END
This document defines the PCEP extensions needed to support Auto-
Bandwidth feature in a Active stateful PCE model
NEW
This document defines the PCEP extensions needed to support an Auto-
Bandwidth feature in an Active stateful PCE model
END
— Section 2.3 —
This value indicates how many times
consecutively, the percentage or absolute difference
Add a comma after “times”.
— Section 3 —
The PCEP speaker supporting this document must have a mechanism
“A PCEP speaker”.
o It is required to identify and inform the PCC, which LSPs are
enabled with Auto-Bandwidth feature. Not all LSPs in some
deployments would like their bandwidth to be dependent on the
real-time bandwidth usage but be constant as set by the operator.
NEW
o It is necessary to identify and inform the PCC which LSPs have
the Auto-Bandwidth feature enabled. In some deployments, not
all LSPs would like their bandwidth to be dependent on the
real-time bandwidth usage, but would rather be constant as set
by the operator.
END
— Section 4.1 —
The initial LSP bandwidth can be set to an arbitrary value (including
zero), in practice, it can be operator expected value based on design
and planning.
NEW
The initial LSP bandwidth can be set to an arbitrary value (including
zero). In practice, it can be set to an expected value based on design
and planning.
END
— Section 4.2 —
When the Auto-Bandwidth feature is enabled, the measured traffic rate
is periodically sampled at each Sample-Interval (which can be
configured by an operator and the default value as 5 minutes) by the
PCC, when the PCC is the head-end node of the LSP. The traffic rate
samples are accumulated over the Adjustment-Interval period (in the
Up or Down direction) (which can be configured by an operator and the
default value as 24 hours).
NEW
When the Auto-Bandwidth feature is enabled, the measured traffic rate
is periodically sampled at each Sample-Interval by the PCC, when the
PCC is the head-end node of the LSP. The sample interval can be
configured by an operator, with a default value of 5 minutes.
The traffic rate samples are accumulated over the Adjustment-Interval
period (in the Up or Down direction). The period can be configured by
an operator, with a default value of 24 hours.
END
The PCC, in-charge of calculating the
bandwidth to be adjusted, can decide to adjust the bandwidth
Remove both commas.
Only if the difference between the
current bandwidth demand (MaxAvgBw) and the current bandwidth
reservation is greater than or equal to the Adjustment-Threshold
(percentage or absolute value) (which can be configured by an
operator and the default as 5 percentage), the LSP bandwidth is
adjusted (upsized) to the current bandwidth demand (MaxAvgBw).
I’m sorry: I can’t made any sense out of this text and, thus, can’t
suggest a fix. Please try rephrasing this. When you do, please make
it more than one sentence, and please avoid consecutive parenthesized
phrases, which are awkward.
However, longer
adjustment-interval can result in an undesirable effect
“a longer”
To avoid this, the
Auto-Bandwidth feature may pre-maturely expire the adjustment-
interval and adjust the LSP bandwidth
“prematurely”, with no hyphen.
“adjustment interval”, with no hyphen.
— Section 5.1 —
o The PCEP speaker that does not recognize the extensions defined in
“A PCEP speaker”
o If the PCEP speaker that supports the extensions defined in this
“If a PCEP speaker supports”
— Section 5.2 —
Future specification can define additional sub-TLVs.
“specifications”
If sub-TLVs are not present, the
default values as specified in this document are used or otherwise
based on the local policy are assumed.
I can’t make sense of that sentence; please re-phrase it.
— Section 5.2.3.2 —
o Reserved: SHOULD be set to zero on transmission and MUST be
ignored on receipt.
Why is this “SHOULD”, when other reserved values have been “MUST”?
(Same comment in 5.2.3.4, 5.2.5.1, 5.2.5.2, 5.2.5.3, and 5.2.5.4.)
====
[1]
https://datatracker.ietf.org/doc/draft-ietf-pce-stateful-pce-auto-bandwidth/ballot/
[2] https://mailarchive.ietf.org/arch/browse/pce/
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