Subject: [mpls] Warren Kumari's No Objection on draft-ietf-mpls-flow-ident-06: (with COMMENT)

From: Warren Kumari <[email-masked]>
Date: Mon, 08 Jan 2018 15:44:35 -0800

Warren Kumari has entered the following ballot position for
draft-ietf-mpls-flow-ident-06: No Objection

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COMMENT:
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Thank you for writing this, I think it is a useful document -- however, it does
have a number of nits which would be nice to address (if you make any other
edits).

Nits:
Section 1.  Introduction
O: "flow identification.The key"
P: "flow identification. The key"
R: missing space

O: performance monitoring of MPLS flows when MPL is used for the encapsulation
of user data packets. P: performance monitoring of MPLS flows when MPLS is used
for the encapsulation of user data packets. R: Typo for MPLS?

O: Indeed it is important that any flow identification technique be invisible
to them and that no remnant of the identification of measurement process leaked
into their network. P: Indeed it is important that any flow identification
technique be invisible to them and that no remnant of the identification of
measurement process leaks into their network. R: Tense / readability.

Section 3.  Loss Measurement Considerations

O: Modern networks, if not oversubscribed, potentially drop relatively
P: Modern networks, if not oversubscribed, generally drop relatively
C: "potentially" makes it sound like this might happen. If a network isn't
oversubscribed it usually won't drop packets.

Section 4.  Delay Measurement Considerations
O: Most of the existing delay measurement methods are active measurement that
depend on the extra injected test packet to evaluate C: I think that this
should be "active measurements" or "active methods". I'm also confused by the
singular of "packet".

O: Also, for injected test packets, these may not be co-routed with the data
traffic due to ECMP, or various link aggregation technologies all of which
distribute flows across a number of paths at the network, or data-link and
hence at the physical layer. C: This sentence is a run on / really confusing. I
know what you are trying to say, but this doesn't communicate it well. Perhaps
"Due to ECMP (or link aggregation techniques) injected test packets may
traverse other links than the data traffic."? Still not great, but I think
easier to parse.

Section 5.  Units of identification

O: In particular note that there may be a need to impose identify at several
different layers of the MPLS label stack. P: "identity" (or perhaps
"identification"?)

O: Such fine grained resolution may be possible by deep packet inspection, but
this may not always be possible, or it may be desired to minimize processing
costs by doing this only in entry to the network, and adding a suitable
identifier to the packet for reference by other network elements. C: This feels
like a run on. Also I *think* it is "fine-grained" and "on entry to the
network" (nits)

O: This allows for the case of instrumenting multiple LSPs operate between the
same pair of nodes. P: This allows for the case of instrumenting multiple LSPs
operating between the same pair of nodes. C: Readability.