[IPFIX] R: R: New AD review of draft-ietf-ipfix-flow-selection-tech-10.txt

["Salvatore D'Antonio" <[e-mail]>]

Dear Benoit,

 

My answers inline.

 

Da: Benoit Claise [mailto:[e-mail]] 
Inviato: giovedì 8 novembre 2012 16:15
A: Salvatore D'Antonio
Cc: [e-mail]; [e-mail];
[e-mail]
Oggetto: Re: R: [IPFIX] New AD review of
draft-ietf-ipfix-flow-selection-tech-10.txt

 

Dear Salvatore,

I removed the comments on which we agree, for clarity.

Dear Benoit,

 

My comments to your comments inline.

 

Da: Benoit Claise [mailto:[e-mail]] 
Inviato: martedì 30 ottobre 2012 23:01
A: [e-mail]; [e-mail]
Cc: [e-mail]
Oggetto: Re: [IPFIX] New AD review of
draft-ietf-ipfix-flow-selection-tech-10.txt

 

 





Intermediate Flow Selection Process: an Intermediate Process as in
      [RFC6183 <http://tools.ietf.org/html/rfc6183> ] that ...
 

 

The new definition improved a lot:

 * Intermediate Flow Selection Process
 
      An Intermediate Flow Selection Process takes Flow Records as its
      input and selects a subset of this set as its output.
      Intermediate Flow Selection Process is a more general concept than
      Intermediate Selection Process as defined in [RFC6183
<http://tools.ietf.org/html/rfc6183> ].  While an
      Intermediate Selection Process selects Flow Records from a
      sequence based upon criteria-evaluated Flow record values and
      passes only those Flow Records that match the criteria, an
      Intermediate Flow Selection Process selects Flow Records using
      selection criteria applicable to a larger set of Flow
      characteristics and information.

But is there a reason why this definition can't be based on "intermediate
Process" from RFC 6183:

Intermediate Process
 
      An Intermediate Process takes a record stream as its input from
      Collecting Processes, Metering Processes, IPFIX File Readers,
      other Intermediate Processes, or other record sources; performs
      some transformations on this stream based upon the content of each
      record, states maintained across multiple records, or other data
      sources; and passes the transformed record stream as its output to
      Exporting Processes, IPFIX File Writers, or other Intermediate
      Processes in order to perform IPFIX Mediation.  Typically, an
      Intermediate Process is hosted by an IPFIX Mediator.
      Alternatively, an Intermediate Process may be hosted by an
      Original Exporter.
 
According to the definition of “Intermediate Process” from RFC 6183, such a
process is typically hosted by an IPFIX Mediator. Alternatively, it may be
hosted by an Original Exporter. In my view, an Intermediate Flow Selection
Process could be also hosted by a Collector.

Sure. Then the Collector becomes a Collector that contains a mediator
function.
I don't see the problem.

 

Ok, it’s clear to me now. I will modify the text of the definition
accordingly.

 

   Intermediate Process
 
      An Intermediate Process takes a record stream as its input from
      Collecting Processes, Metering Processes, IPFIX File Readers,
      other Intermediate Processes, 


My concern if you use your definition is that it doesn't build on the
framework RFC 6183



 

So 

 * Intermediate Flow Selection Process
 
      An Intermediate Flow Selection Process is an Intermediate Process as
in
      [RFC6183 <http://tools.ietf.org/html/rfc6183> ] that takes Flow
Records as its
      input and selects a subset of this set as its output.
      Intermediate Flow Selection Process is a more general concept than
      Intermediate Selection Process as defined in [RFC6183
<http://tools.ietf.org/html/rfc6183> ].  While an
      Intermediate Selection Process selects Flow Records from a
      sequence based upon criteria-evaluated Flow record values and
      passes only those Flow Records that match the criteria, an
      Intermediate Flow Selection Process selects Flow Records using
      selection criteria applicable to a larger set of Flow
      characteristics and information.






 






4.  Flow selection as a Function in the IPFIX Architecture 
   

Thanks for your new figure 1.
One editorial change: change the + in the left vertical line.

Ok, will do.

      +======|========================+      |
      |      |  Mediator              |      |
      +    +-V-------------------+    |      |
      |    | Collecting Process  |    |      |
      +    +---------------------+    |      |
      |    | Intermediate Flow   |    |      |
      |    | Selection Process   |    |      |
      +    +---------------------+    |      |
      |    |  Exporting Process  |    |      |
      +    +-|-------------------+    |      |
      +======|========================+      |
      


5.1.  Flow Filtering 

   Flow Filtering is a deterministic function on the IPFIX Flow Record 
   content.  If the relevant flow characteristics are already observable 
   at packet level (e.g.  Flow Keys), Flow Filtering can be applied 
   before aggregation at packet level.  In order to be compliant with 
   this document, at least the Property Match Filtering MUST be 
   implemented. 

This contradicts.

   In order to be compliant with this document, at
   least one of the flow selection schemes MUST be implemented.

Actually, wrong cut/paste.
This contradicts, in section 1:

   In order to be compliant with this document, at
   least the Property Match Filtering MUST be implemented.

 

This comment is not clear to me. Both in Section 1 and in Section 5.1 (Flow
Filtering) I used the same sentence “In order to be compliant with this
document, at least the Property Match Filtering MUST be implemented”.

 

Solved with version 12.
However, I'm wondering if the resolution is correct.
version 11:
       

   In order to be compliant with this document, at
   least one of the flow selection schemes MUST be implemented. 
 
   ...
 
   In order to be compliant with this document, at
   least the Property Match Filtering MUST be implemented.


Version 12:

    In order to be compliant with this document, at
   least the Property Match Filtering MUST be implemented.


Listing all the selection techniques, 

   5
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5> .  Flow Selection Techniques  . . . . . . . . . . . . . . . . . . 10
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-10>

     5.1
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.1> .  Flow Filtering . . . . . . . . . . . . . . . . . . . . . . 11
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-11>

       5.1.1
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.1.1> .  Property Match Filtering . . . . . . . . . . . . . . . 11
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-11>

       5.1.2
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.1.2> .  Hash-based Flow Filtering  . . . . . . . . . . . . . . 11
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-11>

     5.2
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.2> .  Flow Sampling  . . . . . . . . . . . . . . . . . . . . . . 12
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-12>

       5.2.1
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.2.1> .  Systematic sampling  . . . . . . . . . . . . . . . . . 12
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-12>

       5.2.2
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.2.2> .  Random Sampling  . . . . . . . . . . . . . . . . . . . 12
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-12>

     5.3
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.3> .  Flow-state Dependent Flow Selection  . . . . . . . . . . . 13
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-13>

     5.4
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#section-
5.4> .  Flow-state Dependent Packet Selection  . . . . . . . . . . 14
<http://tools.ietf.org/html/draft-ietf-ipfix-flow-selection-tech-12#page-14>



It means that a device that implements Flow Sampling was compliant with
version 11 thanks to the sentence "In order to be compliant with this
document, at least one of the flow selection schemes MUST be implemented"
and is not compliant any longer with version 12
It seems like an important change to me since the WGLC, on which the WG must
agree.

 

I agree. A new WGLC is needed to have feedback on this change from the WG.

 

Best regards,

 

Salvatore



Regards, Benoit












 

 

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