[Dime] Martin Stiemerling's Discuss on draft-ietf-dime-congestion-flow-attributes-01: (with DISCUSS and COMMENT)

["Martin Stiemerling" <[e-mail]>]

Martin Stiemerling has entered the following ballot position for
draft-ietf-dime-congestion-flow-attributes-01: Discuss

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DISCUSS:
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No general objection to the publication of the document. However, I am
relaying a question from David Black as a DISCUSS point. 

I assume that the draft is more than unclear in Section 3.2  about what
traffic means. Is it a particular flow, a single packet, etc?

"I found an ECN concern, and hence added the TSV ADs to the CC line.

Section 3.2 says:

   The Congestion-Treatment AVP (AVP Code TBD) is of type Grouped and
   indicates how congested traffic, i.e., traffic that has Explicit
   Congestion Notification Congestion Experienced marking set or some
   other administratively defined criteria, is treated.  

That appears to say that the congestion treatment may be applied
solely to packets that have the CE (Congestion Experienced) marking.
That would be a problem, because the defined semantics of a CE marking
is that it applies to the entire flow (e.g., causes TCP to react as if
a packet has been dropped), hence the congestion treatment ought
to apply to the entire flow.

In other words, one wants to be able to use the ECN-IP-Codepoint
AVP as part of the condition that determines whether the filter rule
matches, but ignore that AVP (i.e., wildcard it) in determining what
traffic the action applies to, so that the response to detecting a
congested flow (i.e., packets with ECN field containing CE) applies
to all packets in the flow, regardless of the value in the CE field.

Otherwise, the result may be ineffective, as it won't encompass packets
in the congested flow that aren't CE-marked.

Am I reading the draft correctly?"


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COMMENT:
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Section 1, 1st paragraph: 
It says "The first AVP provides direct support for ECN [RFC3168] in the
IP header“. I am  sure that your draft is  ot providing any support for
ECN in the IP header, as we have ECN in the IP header already, isn't it.
I guess you mean something like this "The first AVP provides direct
support for filtering ECN marked traffic[RFC3168]“