RFC 3289, "Management Information Base for the Differentiated Services Architecture", May 2002

Errata ID: 2976
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: Ina Singh
Date Reported: 2011-09-21
Held for Document Update by: Wesley Eddy

Section 3.4.5. says:

   diffServRandomDropInvProbMax represents Pmax (inverse).  This MIB
   does not represent Pmin (assumed to be zero unless otherwise
   represented).  In addition, since message memory is finite, queues
   generally have some upper bound above which they are incapable of
   storing additional traffic.  Normally this number is equal to Qclip,
   specified by diffServAlgDropQThreshold.

It should say:

       The average queue depth beyond which traffic has a probability
       indicated by diffServRandomDropProbMax of being dropped or
       marked. Note that this differs from the physical queue limit,
       which is stored in diffServAlgDropQThreshold. 

Notes:

diffServRandomDropInvProbMax should be removed

Attaching the e-mail confirmation from Fred :
==============================================


From: Fred Baker (fred)
Sent: Tuesday, September 20, 2011 10:54 PM
To: Ina Singh (inasingh)
Subject: Re: RFC3289/DiffesrvMIB SFS

Thanks for pointing this out. Correct me if I'm wrong; it looks to me like diffServRandomDropInvProbMax only shows up in the comment in section 3.4.5, and diffServRandomDropProbMax is used throughout the MIB. Yes, the comment should be fixed, but the MIB is itself correct with diffServRandomDropProbMax. Correct?

The right thing to do is file an erratum against RFC 3289, so that if it is edited in the future the error can be picked up, and implementers can see it.

http://www.ietf.org/iesg/statement/errata-processing.html describes the process.


On Sep 20, 2011, at 6:50 PM, Ina Singh (inasingh) wrote:

> Hey Fred,
>
> While implementing RFC3289/DiffesrvMIB SFS recently on IOS, we noticed the following error :
> It would seem that diffServRandomDropInvProbMax was replaced by
> diffServRandomDropProbMax (?) , but the reference to “diffServRandomDropInvProbMax” was not removed on subsequent versions.
>
> Can you please confirm, if so, what’s the procedure to correct it ..
>
> Thanks in advance for your help in this and appreciate your time..
>
> Ina
>
> Definition of "diffServRandomDropInvProbMax" upto version 7, here is a link for draft version 6.
>
> http://tools.ietf.org/html/draft-ietf-diffserv-mib-06
>
> iffServRandomDropInvProbMax OBJECT-TYPE
> SYNTAX Unsigned32
> MAX-ACCESS read-create
> STATUS current
> DESCRIPTION
> "The worst case random drop probability, expressed as
> the inverse of the drop probability. With special
> case of the value zero meaning zero probability of
> drop.
>
> For example, if every packet may be dropped in the
> worst case (100%), this has the value of
> 4,294,967,295."
> ::= { diffServRandomDropEntry 6 }
>
>
>
> In contrast to "diffServRandomDropProbMax" starting from version 8.
>
>
> diffServRandomDropProbMax OBJECT-TYPE
>
> SYNTAX Unsigned32 (0..1000)
> MAX-ACCESS read-create
> STATUS current
> DESCRIPTION
> "The worst case random drop probability, expressed in drops per
> thousand packets.
>
> For example, if in the worst case every arriving packet may be
> dropped (100%) for a period, this has the value 1000.
> Alternatively, if in the worst case only one percent (1%) of
> traffic may be dropped, it has the value 10."
> ::= { diffServRandomDropEntry 6 }

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