Re: [manet] undirectional or bidirectional (Was Re: I-D Action: draft-ietf-manet-dlep-da-credit-extension-00.txt)

"James A. (Jim) Stevens" <james.a.stevens@rockwellcollins.com> Tue, 14 February 2017 23:28 UTC

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From: "James A. (Jim) Stevens" <james.a.stevens@rockwellcollins.com>
Date: Tue, 14 Feb 2017 17:28:15 -0600
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Subject: Re: [manet] undirectional or bidirectional (Was Re: I-D Action: draft-ietf-manet-dlep-da-credit-extension-00.txt)
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Henning, I think I understand and agree with everything you wrote, but not
absolutely sure, so want to double check.

In your second paragraph, when you say that '"flow control from the router
towards the radio is THE most important part, it is practically necessary
for all radios if you want to do some kind of Priorization on the router
​" ​

I can read the phrase "flow control from the router towards the radio" two
ways.

I think you mean meaning #1 below, correct?

(1) radio sends unidirectional credit flow to router to perform "flow
control from router towards radio"

or

(2) router sends unidirectional credit flow to radio to perform "flow
control from router towards radio"

Similarly for confusion in third paragraph on "flow control from the radio
to the router".

I agree if you meant meaning #1 above and disagree if  you meant meaning #2
above.

I strongly agree with your first and fourth paragraphs.

Thanks,
Jim Stevens

==  Tue, 14 Feb 2017 08:31:02 +0100 email from Henning Rogge
==
==
== Hi,
==
== in general flow control is about keeping the "bottleneck/queue" mostly
== on the router, where we can control it at a central point. That is an
== important part of the design goal of DLEP.
==
== I think flow control from the router towards the radio is THE most
== important part, it is practically necessary for all radios if you want
== to do some kind of Priorization on the router.
==
== Flow control from the radio to the router is a (in my opinion) rare
== cornercase for radios with a TDMA that can control incoming traffic.
==
== Because of this I think an unidirectional flow control extension is a
== good idea, otherwise we add a lot of complexity which will nearly
== never be used.
==
== Henning Rogge
==