Best practices for DM Managed Objects
KP Bhat
practices for defining OMA DM MOs (as summarized from the ACMO
document)
Thanks
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1) All MOs should have a sub-node allowing a vendor to include any
proprietary sub-nodes in order to include any vendor specific
extensions. The name of this node should be “Ext”
2) If a collection of related nodes within an MO definition is
expected to be repeated a certain number of times, it is highly
recommended to introduce an unnamed node in the MO definition and have
all the nodes subtend from this unnamed node. Traditionally unnamed
nodes are represented by the letter “x”.
3) “x” should never be chosen as the name of any node in the MO
definition.
4) Sibling instances of “x” cannot have the same name and it is also
recommended not to have any named nodes as siblings of an “x” node.
This is to reduce chances of clashes with instances of “x” that will
be generated by the client
5) As a general rule grant only Get access type on the various nodes
within the standardized MOs definition, except in some special cases,
where higher other access types may be required
6) The allowed values for access type are any combination of the
following:
(+) Get
(+) Replace
(+) Exec
(+) Add
(+) Delete
(+) Copy
7) In some instances there may be a need to explicitly disallow a
certain type of access for a given node. This is indicated by
prepending the access type with the keyword “No”. For example, it is
strongly recommended that any node that deals with security related
information, such as user-id and password, should not be granted the
Get or Copy access type. The Min. Access Types for such a node should
include No Get and No Copy.
8) The Add and Delete access types are generally provided for unnamed
nodes for which the Occurrence is one of the following: ZeroOrOne,
ZeroOrMore or ZeroOrN.
9) It is a good practice to grant an optional node the Get access
type, in addition to other access types that it may support. For
example, an optional node that supports the Exec access type should
have its Min. Access Types set to “Get, Exec” whereas a required node
that supports the Exec access type should have its Min. Access Types
set to “Exec” only.
10) Specifying only the Get access type for a node within the MO does
not restrict an implementation from supporting additional access types
for that node since the standardized MO only specifies the minimum set
of access types that the node is required to support.