RE: [ipcdn] RE: AD re-review: draft-ietf-ipcdn-docs-rfmibv2-13.txt Topic: docsIfUpchannelStatus

["Eduardo Cardona" <[e-mail]>]

IPCDN participants, 
Bert W. and Randy P. in their review of the RFI MIB pointed a
non-standard behavior for the defined cloning mechanism of upstream
Interfaces: 


Please review the draft changes below
My intention is to publish a draft this weekend so it will be available
for review of the Vancouver IETF meeting, any comments are welcome  - I
will work on other edits and formats



Issue:
After clonningFrom a temporary interface ( which never comes active) 
The MIB requires to set the Update object to 'true'  and update the
target physical interface

The problem IETF sees is that a non-active rows are non-existing rows,
therefore the update set to copy back the parameters to the physical
interface is not conventional approach (not visible to use such
parameters)

Based on internal emails with Bert and Jean-Francois, it was suggested
to add an extra step in the process after the cloneFrom command and
parameters are adjusted: A set to RowStatus 'active' will validate that
the values are acceptable for the target physical interface, then the
update 'true' command is executed to copy the parameters from the
temporary interface to the physical interface
Finally the manager can delete the temporary entry with a RowStatus set
to 'destroy'


Also a new descriptive section 3.1.5 was added to present the offline
upstream parameters handling  

Below are the snapshots of the changes:    



3.1.5.  Offline Upstream Parameters Handling

3.1.5.1.  Overview

   This section describes the offline configuration of the DOCSIS 2.0
   upstream logical interface parameters.  The purpose of this feature
   is to guarantee that upstream logical interface parameters such as
   modulation profile, channel type, mini-slot Size and SCDMA attributes
   are consistent prior to commit changes to an active upstream logical
   interface.  This mechanism can reduce possible downtime of the
   upstream interface by minimizing SNMP SET operations to in-service
   upstream interfaces.  This mechanism is supported by CMTSs and is not
   applicable to CMs.

3.1.5.2.  Operation

   This mechanism uses three upstream channel MIB objects defined for
   DOCSIS 2.0 CMTS implementations:

   docsIfUpChannelStatus - The RowStatus object for the creation of
   temporary interfaces in the upstream interface table.  A temporary
   entry is used to modify, validate and commit upstream parameters of a
   physical interface.  In the CMTS, a physical upstream interfaces
   refers to an upstream logical channels interfaces.

   docsIfUpChannelCloneFrom - This object has the function to associate
   a physical interface with a temporary interface with the purpose of
   updating the upstream parameters of the physical interface.

   docsIfUpChannelUpdate - This object is the commit object that
   transfer the validated upstream parameters from the temporary
   interface to the physical interface.

   The offline upstream parameters handling operation is as follows:

   o  A temporary interface is create with docsIfUpChannelStatus set to
      'createAndWait', which turns the new create entry status to
      'notReady'.

   o  A SET to docsIfUpChannelCloneFrom in the temporary interface to
      the physical interface ifIndex value performs two actions:

      *  Create the association of the physical interface to the
         temporary interface.

      *  Copy the original upstream parameters from the physical
         interface to the temporary interface which turns its status to
         'notInService'.

   o  The operator modifies the temporary interface parameters to the
      desired values.

   o  At this point, a SET to 'active' to the RowStatus of the temporary
      interface is successful if all parameters in the temporary
      interface are valid for the associated physical interface;
      otherwise, the temporary entry remains with status 'notInservice'
      and the SET returns error 'commitFailed'.

   o  When the temporary interface status is 'active' a SET to
      docsIfUpChannelUpdate to 'true' transfer the temporary interface
      parameters values to the physical interface.

   o  After completion of the update operations, the temporary interface
      is destroyed setting the docsIfUpChannelStatus to 'destroy'.

3.1.5.3.  Relation of docsIfUpChannelStatus and ifMib

   The main purpose of docsIfUpChannelStatus is the creation of
   temporary interfaces for offline handling of the configuration of
   physical interfaces; It does not manage the creation or control of
   physical interfaces.  To maintain a consistent operation and status
   report of interfaces, this object does not control or reflect
   administrative and operational status of the physical interfaces.

-----------------  

Then the Objects changes: 
Entry 
CloneFrom
Update
Status

   docsIfUpstreamChannelEntry OBJECT-TYPE
        SYNTAX      DocsIfUpstreamChannelEntry
        MAX-ACCESS  not-accessible
        STATUS      current
        DESCRIPTION
            "List of attributes for a single upstream channel.  For
             DOCSIS 2.0 CMTSs, an entry in this table exists for
             each ifEntry with an ifType of docsCableUpstreamChannel
             (205).
             For DOCSIS 1.x CM/CMTSs and DOCSIS 2.0 CMs, an entry in
             this table exists for each ifEntry with an ifType of
             docsCableUpstream (129).
             For DOCSIS 2.0 CMTSs two classes of interfaces can be
             defined for this table:

               o Upstream Physical Interfaces: The traditional DOCSIS
                 1.x CMTS upstream interface ifType 129 and the DOCSIS
                 2.0 ifType 205 that are functional. In other words,
                 interfaces that represents upstream receivers within
                 an RF MAC interface.
                 Entries of physical interfaces are exposed to the
                 management interface with their corresponding
                 ifStack hierarchy and are not administratively
                 created by this table.

              o Upstream Temporary Interfaces: A fictitious
                 interface created with the purpose of manipulating
                 the parameters of a physical interface parameters
                 offline, then validate values consistency prior to
                 update the target physical interface.

             This mechanism helps to minimize service disruption
             originated in situations where a group of interface
             parameters values need to be inconsistent each other
             in SET operations. Instead, a temporary buffer
             (temporary interface) is provided to allow the CMTS
             to validate the parameters offline."
        INDEX { ifIndex }
        ::= { docsIfUpstreamChannelTable 1 }



   docsIfUpChannelCloneFrom OBJECT-TYPE
        SYNTAX      InterfaceIndexOrZero
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "Intended for use when a temporary upstream
             row entry is created to manipulate and update parameters
             of a physical interface.

             This object contains the ifIndex value of the physical
             interface row entry whose parameters are to be adjusted.

             Upon setting this object to the ifIndex value of a physical
             interface the values of the objects listed below from the
             ifIndex referenced are copied to this entry:

             docsIfUpChannelFrequency,
             docsIfUpChannelWidth,
             docsIfUpChannelModulationProfile,
             docsIfUpChannelSlotSize,
             docsIfUpChannelRangingBackoffStart,
             docsIfUpChannelRangingBackoffEnd,
             docsIfUpChannelTxBackoffStart,
             docsIfUpChannelTxBackoffEnd,
             docsIfUpChannelScdmaActiveCodes,
             docsIfUpChannelScdmaCodesPerSlot,
             docsIfUpChannelScdmaFrameSize,
             docsIfUpChannelScdmaHoppingSeed,
             docsIfUpChannelType, and
             docsIfUpChannelPreEqEnable

             Setting this object to a non-existent or temporary
             upstream returns an error 'wrongValue'.
             This object MUST contain a value of zero for physical
             interfaces entries."
        ::= { docsIfUpstreamChannelEntry 16 }


   docsIfUpChannelUpdate OBJECT-TYPE
        SYNTAX      TruthValue
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "Used to perform the copy of adjusted parameters from the
             temporary upstream row to the physical upstream row
             indicated by the docsIfUpChannelCloneFrom object.  The
             transfer is initiated through an SNMP SET to 'true' of
             this object.
             A failed SET to 'true' returns error 'commitFailed'
             if docsIfUpChannelStatus value is 'notInService', which
             means, the adjusted parameter values are not compatible
             each other or had not been yet validated.
             Reading this object always return 'false'."
        ::= { docsIfUpstreamChannelEntry 17 }

   docsIfUpChannelStatus OBJECT-TYPE
        SYNTAX      RowStatus
        MAX-ACCESS  read-create
        STATUS      current
        DESCRIPTION
            "This object is only used for the creation of a temporary
             upstream row with the purpose of adjusting channel
             parameters of a physical upstream channel entry.

             The following restrictions apply to this object:
             1. This object is not writable for physical interfaces.
             2. Temporary interface entries are created only by SET to
                RowStatus createandWait(5).
             3. ifAdminStatus from the Interface MIB RFC 2863 is used
                to take a physical upstream channel offline consistent
                with DOCSIS 1.x operation indicated in RFC 2670.
                In addition:
                 o ifAdminStatus 'down' is reflected in this object as
                   status 'notInService'.
                 o ifOperSatus 'down' while ifAdminStatus 'up' is
                   reflected in this object as status 'notInservice'.
             4. Temporary created rows MUST be set to 'active' with the
                purpose of validate the upstream parameters consistency
                prior to transfer the parameters to the physical
                interface.
             5. Temporary entries MUST NOT persist at reinitialization
                of the managed system.

             Below is a mandatory procedure for adjusting an upstream
             physical interface :
             1. Create a temporary interface entry through an SNMP SET
                using 'createAndWait'. At this point, the RowStatus
                report a value 'notReady'.
                Manager entity uses an ifIndex value outside the
                operational range of the managed system for temporary
                interfaces.
             2. Set the docsIfUpChannelCloneFrom object to the ifIndex
                value of the physical row whose parameters require
                adjustment. Now docsIfUpChannelStatus reports
                'notInService'.
             3. Adjust the parameter values using the new temporary
                row.
             4. Validate that all parameters are consistent by setting
                docsIfUpChannelStatus to 'active'. A Failure to set the
                RowStatus to 'active' returns error 'commitFailed' which
                means the parameters are not compatible with the
                target physical interface.
             5. With docsIfUpChannelStatus 'active' trasfer the
                parameters to the target physical interface by setting
                the object docsIfUpChannelUpdate to 'true'
             5. Delete the temporary row with a SET to
                docsIfUpChannelStatus to 'destroy'."
        ::= { docsIfUpstreamChannelEntry 18 }


-- Compliance statements set back to similar wording as D-12 


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