[Gen-art] Gen-ART Last Call review of draft-ietf-manet-olsrv2-dat-metric-08

[Paul Kyzivat <[e-mail]>]

[In progress - not ready for sending]

I am the assigned Gen-ART reviewer for this draft. The General Area 
Review Team (Gen-ART) reviews all IETF documents being processed by the 
IESG for the IETF Chair. Please treat these comments just like any other 
last call comments. For more information, please see the FAQ at 
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Document: draft-ietf-manet-olsrv2-dat-metric-08
Reviewer: Paul Kyzivat
Review Date: TBS
IETF LC End Date: 2015-11-23
IESG Telechat date: 2015-12-03

Summary:

This draft is basically ready for publication as an Experimental RFC, 
but has nits that should be fixed before publication.

Major: 0
Minor: 0
Nits:  5

Nits:

* Section 1:

"Appendix A contains a few possible steps to improve the DAT metric."

This is the first occurrence of the "DAT" acronym. It took me a bit to 
realize this must be referring to "Directional AirTime". Could you 
please define the acronym *before* the first use? (Perhaps in the prior 
paragraph where "Directional Airtime" is first used.)

* Section 2:

"These networks employ link layer retransmission to increase the 
delivery probability and multiple unicast data rates."

I'm not sure how to parse this sentence. Is it intended to be:

"These networks employ link layer retransmission to increase (the 
delivery probability) and (multiple unicast data rates)."

OR "These networks employ link layer retransmission to (increase the 
delivery probability) and (multiple unicast data rates)."

Either way I don't understand what "multiple unicast data rates" means. 
Can you clarify this?

* Section 7:

You call these *constants*, in contrast to the *parameters* defined in 
section 6. But you then suggest conditions under which they could be 
changed. Perhaps they should simply be included with the parameters, but 
with strong warnings about diverging from the recommended values.

Else, it would be good to define these *before* the parameters, because 
that would avoid the forward reference to DAT_MAXIMUM_LOSS.

* Section 9.3/9.4:

Are you considering these to be mutually exclusive? Or is a HELLO 
message processed first by 9.3, and then by 9.4?

Since there is considerable overlap in processing between the two, and 
it would presumably be wrong to do that twice, I guess you must assume 
them to be mutually exclusive. But I presume HELLO messages arrive in 
incoming packets, so 9.3 sounds like it ought to apply to them.

If I guessed right, then I suggest revising 9.3 to start "For each 
incoming packet that is not a HELLO message, ..."

* Section 10.2:

IIUC steps 5.3 & 5.4 are just the hard way of saying:

   bitrate := MAX(L_DAT_rx_bitrate, DAT_MINIMUM_BITRATE)