Re: [Dime] [dime] #44: Incorrect sequence number behavior

[Steve Donovan <[e-mail]>]

Lionel,

I believe that Ben's issue was with the following wording in section 4.3

   The Sequence-Number AVP indicates the "freshness" of the OC-OLR AVP.
   It is possible to replay the same OC-OLR AVP multiple times between
   the overload control endpoints, however, when the OC-OLR AVP content
   changes or sending endpoint otherwise wants the receiving endpoint to
   update its overload control information, then the OC-Sequence-Number
   AVP MUST contain a new greater value than the previously received.
   The receiver SHOULD discard an OC-OLR AVP with a sequence number that
   is less than previously received one.


The wording you reference is in section 5.5.2.

The above wording can be improved by changing the last sentence to "The
reacting node SHOULD discard an OC-OLR AVP with a sequence number that
is less than or equal to the previously received sequence number."

Steve

On 2/8/14 10:53 AM, [e-mail] wrote:
> Hi Ben,
>
> The case "equal" is discussed in the previous sentence.
>
> Check the following:
>
>    The received OC-Supported-Features AVP does not change the existing
>    overload condition and/or traffic abatement algorithm settings if the
>    OC-Sequence-Number AVP contains a value that is equal to the
>    previously received/recorded one.  If the OC-Supported-Features AVP
>    is received for the first time for the reporting node or the OC-
>    Sequence-Number AVP value is less than the previously received/
>    recorded one (and is outside the valid overflow window), then either
>    the sequence number is stale (e.g. an intentional or unintentional
>    replay) and SHOULD be silently discarded.
>
> The first sentence implies that the received OLR is ignored. 
>
> And actually, there is something wrong in the last sentence. At the end, 
>
>    recorded one (and is outside the valid overflow window), then either
>    the sequence number is stale or replay (e.g. an intentional or unintentional
>    replay) and SHOULD be silently discarded.
>
> The "either" in the first line should be removed.
>
> Regards,
>
> Lionel
>
>
> -----Message d'origine-----
> De : DiME [mailto:[e-mail]] De la part de dime issue tracker
> Envoyé : vendredi 7 février 2014 22:49
> À : [e-mail]; [e-mail]
> Cc : [e-mail]
> Objet : [Dime] [dime] #44: Incorrect sequence number behavior
>
> #44: Incorrect sequence number behavior
>
>  section 4.3 says that the receiver should discard an OLR with a sequence
>  number less than the most recent. That should be less than or equal.
>  Technically, re-applying the same OLR should make no difference, but it's
>  never needed, and could be error prone if the sender screwed something up.
>