Subject: [Dime] issue #56 proposed conclusion

From: "Wiehe, Ulrich (NSN - DE/Munich)" <[email-masked]>
Date: Thu, 20 Mar 2014 13:08:27 +0000

#56: Bad Description of Overload Control State

Dear all,

I have received comments from Steve, MCruz and Jouni.

I believe all comments are covered by the following proposed text:

    5.5.1.  Overload Control State (OCS)

    5.5.1.1   Overload Control States for reacting nodes

    A reacting node maintains per supported Diameter application
    - a host-type Overload Control State for each Destination-Host towards
      which it sends host-type requests and
    - a realm-type Overload Control State for each Destination-Realm towards
      which it sends realm-type requests.

    A host-type Overload Control State may be identified by the pair of
    Application-Id and Destination-Host.
    A realm-type Overload Control State may be identified by the pair of
    Application-Id and Destination-Realm.
    The host-type/realm-type Overload Control State for a given pair of
    Application and Destination-Host / Destination-Realm could include the
    following information:
    - Sequence number (as reveived in OC-OLR)
    - Time of expiry  (deviated from validity duration as received in OC-OLR
      and time of reception)
    - Selected Abatement Algorithm (as received in OC-Supported-Features)
    - Algorithm specific input data (as received within OC-OLR, e.g.
      Reduction Percentage for Loss)

    5.5.1.2   Overload Control States for reporting nodes

    A reporting node maintains per supported Diameter application and per
    supported (and eventually selected) Abatement Algorithm an Overload
    Control State. 

    An Overload Control State may be identified by the pair of Application-Id
    and supported Abatement Algorithm.

    The Overload Control State for a given pair of Application and Abatement
    Algorithm could include the information:
    - Sequence number
    - Validity Duration and Expiry Time
    - Algorithm specific input data (e.g. Reduction Percentage for Loss)

    5.5.1.3  Maintaining Overload Control States

    Reacting nodes create a host-type OCS identified by OCS-Id = (app-id,host-id) when receiving
    an answer message of application app-id containing an Orig-Host of host-id and a
    host-type OC-OLR AVP unless such host-type OCS already exists.

    Reacting nodes create a realm-type OCS identified by OCS-Id = (app-id,realm-id) when receiving
    an answer message of application app-id containing an Orig-Realm of realm-id and a
    realm-type OC-OLR AVP unless such realm type OCS already exists.

    Reacting nodes delete an OCS when it expires (i.e. when current time
    minus reception time is greater than validity duration).

    Reacting nodes update the host-type OCS identified by OCS-Id = (app-id,host-id) when
    receiving an answer message of application app-id containing an Orig-Host of
    host-id and a host-type OC-OLR AVP with a sequence number higher than the
    stored sequence number.

    Reacting nodes update the realm-type OCS identified by OCS-Id = (app-id,realm-id) when
    receiving an answer message of application app-id containing an Orig-Realm of
    realm-id and a realm-type OC-OLR AVP with a sequence number higher than the
    stored sequence number.

    Reporting nodes create an OCS identified by OCS-Id = (app-id,Alg) when receiving a
    request of application app-id containing an OC-Supported-Features AVP
    indicating support of the Abatement Algorithm Alg (which the reporting
    node selects) while being overloaded, unless such OCS already exists.

    Reporting nodes delete an OCS when it expires.

    Reporting nodes update the OCS identified by OCS-Id = (app-id,Alg) when they detect the
    need to modify the requested amount of application app-id traffic reduction.

Ulrich