Jitter Considerations in Mobile Ad Hoc Networks (MANETs)
draft-ietf-manet-jitter-04

Note: This ballot was opened for revision 04 and is now closed.

Lars Eggert (was Discuss) No Objection

Comment (2007-11-29)
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I originally had a DISCUSS on whether this document should go for BCP or Experimental rather than Informational. Off-list discussion with the chairs and ADs has made it clear that this technique is too cooked for Experimental but the guidelines aren't clear enough for BCP. Hence, the desire is to stay with Informational.

I'm OK with this resolution, but would in this case strongly suggest to avoid the use of RFC2119 language, which makes it sound like this document makes standards-level recommendations without actually being able to do so.


Section 4., paragraph 1:
>    This document does not specify a protocol, nor does it mandate
>    specific node or protocol behavior.

  DISCUSS: Then its use of RFC2119 terms is confusing. Section 5 is full
  of recommendations for node and protocol behavior - example: "In order
  to prevent nodes in a MANET from simultaneous transmission, (...) a
  randomization of the transmission time of packets by nodes, known as
  jitter, SHOULD be employed." How is this not a recommendation?


Section 5.4., paragraph 2:
>    o  While jitter may resolve the problem of simultaneous
>       transmissions, the timing changes (in particular the delays) it
>       introduces will otherwise typically have a negative impact on a
>       well-designed protocol.  Thus MAXJITTER SHOULD always be
>       minimized, subject to acceptably achieving its intent.

  This doesn't give any concrete guidance on how to pick MAXJITTER. If I
  were to design a protocol, how would I know which values of MAXJITTER
  to use for my messages? (The guidelines for periodic messages below a
  bit more concrete.)


Section 5.4., paragraph 4:
>       *  it MUST NOT be greater than MESSAGE_INTERVAL/2;
>       *  it SHOULD be significantly less than MESSAGE_INTERVAL; a value
>          not greater than MESSAGE_INTERVAL/4 is RECOMMENDED.

  There is some redundancy between these bullets.


Section 5.4., paragraph 5:
>    o  If MESSAGE_MIN_INTERVAL > 0, then:

  How can MESSAGE_MIN_INTERVAL not be greater than zero?

>       *  MAXJITTER MUST NOT be greater than MESSAGE_MIN_INTERVAL;
>       *  MAXJITTER SHOULD NOT be greater than MESSAGE_MIN_INTERVAL/2.

  Also, there is some redundancy between these bullets and the ones
  above.


Section 5.4., paragraph 6:
>    o  As well as the decision as to whether to use jitter being
>       dependent on the medium access control and lower layers, the
>       selection of the MAXJITTER parameter SHOULD be appropriate to
>       those mechanisms.

  What is "appropriate to those mechanisms"; can you give guidelines or
  maybe just some examples?


Section 5.4., paragraph 8:
>    o  The choice of MAXJITTER used when forwarding messages MAY also
>       take into account the expected number of times that the message
>       may be sequentially forwarded, up to the network diameter in hops.

  How would one take this into account? Would I lengthen or shorten
  MAXJITTER? Guidelines?

(Jari Arkko; former steering group member) Yes

Yes ( for -** No value found for 'p.get_dochistory.rev' **)
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(Lisa Dusseault; former steering group member) Yes

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(Ross Callon; former steering group member) Yes

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(Chris Newman; former steering group member) No Objection

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(Cullen Jennings; former steering group member) No Objection

No Objection ( for -** No value found for 'p.get_dochistory.rev' **)
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(Dan Romascanu; former steering group member) No Objection

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(David Ward; former steering group member) (was Discuss) No Objection

No Objection ()
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(Magnus Westerlund; former steering group member) No Objection

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(Mark Townsley; former steering group member) No Objection

No Objection ( for -** No value found for 'p.get_dochistory.rev' **)
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(Ron Bonica; former steering group member) (was No Record, No Objection) No Objection

No Objection ( for -** No value found for 'p.get_dochistory.rev' **)
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(Russ Housley; former steering group member) No Objection

No Objection ( for -** No value found for 'p.get_dochistory.rev' **)
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(Tim Polk; former steering group member) No Objection

No Objection ( for -** No value found for 'p.get_dochistory.rev' **)
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