ACSE:

The Association Control Service Element (ACSE) is used to establish and release associations between application entities. Before any management operations can be performed using CMIP, it is necessary for the two application entities involved to form an association. Either the manager or the agent can initiate association establishment. ACSE allows the manager and agent to exchange application entity titles for the purpose of identification and application context names to establish an application context. As stated above, an application context defines what service elements (for instance, ROSE and CMISE) may be used over the association. After the association is established, ACSE is not used again until the association is released by the manager or agent.

ROSE:

The Remote Operation Service Element (ROSE) is the ISO equivalent of remote procedure call. ROSE allows the invocation of an operation to be performed on a remote system. The Remote Operation protocol contains an invoke identifier for correlating requests and responses, an operation code, and an argument field for parameters specific to the operation. ROSE can only be invoked once an application association has been established. CMIP uses the transaction-oriented services provided by ROSE for all its requests and responses. CMIP also uses the error response facilities provided by ROSE.

Scoping:

Scoping is meant to be understood in terms of the containment hierarchy. A position at a certain level of the containment tree is defined by the CMIS Managed Object Class parameter. The CMIS Scope parameter is then interpreted relative to this "base" managed object. The Scope parameter can be used to select the base object alone, all managed objects in the entire subtree (of the containment tree) below the base object, or all managed objects in the "n"th level (n = 1, 2, 3,...) below the base object.

Filtering:

Within the objects selected as a result of the scope parameter, it is possible to further refine the selection of managed objects through the use of filtering. Filtering provides the ability to select a subset of these objects based on conditions applied to attribute (e.g., IP routing table entries with the "ipRouteAge> 100") and logical operations (and, or, not).

Linked Replies:

If the reply to a single request for a set of managed objects results in more than one managed object being returned, all of these managed objects cannot be returned together in a single CMIP response PDU. The reason for this is that the structure of the CMIP response PDU only has a single field for containing object instance information. Since each managed object has its own instance information, each managed object must be returned in a separate CMIP PDU. In such a case, the CMIP Linked Reply PDU is used. The Linked Reply PDU provides a means of associating each of the multiple replies with the original request that generated them. Thus, a single CMIP Get Request PDU that uses scoping and filtering would result in zero or more CMIP Linked Reply PDUs being returned before a final CMIP Get Result PDU.

CMISE:

The Common Management Information Service Element (CMISE) is the service element that provides the basic management services. The CMISE is a user of both ROSE and ACSE. The CMISE provides both onfirmed and unconfirmed services for reporting events and retrieving and manipulating management data. These services are used by manager and agent application entities to exchange management information. In addition, the CMISE also provides the ability to issue a series of (multiple) linked replies in response to a single request. CMIS services can be divided into two main classes: management association services and information transfer services. Furthermore, there are two types of information transfer services: management notification services and management operation services. In addition to the other CMIS services, the CMISE provides facilities that enable multiple responses to confirmed operations to be linked to the operation by the use of a linked identification parameter.

The CMISE makes use of the OSI Application layer service elements to complete the processing of these requests

1. ACSE:

• The Association Control Service Element (ACSE) is used to establish and release associations between application entities.

• Before any management operations can be performed using CMIP, it is necessary for the two application entities involved to form an association.

• Either the manager or the agent can initiate association establishment.

• ACSE allows the manager and agent to exchange application entity titles for the purpose of identification and application context names to establish an application context.

• As stated above, an application context defines what service elements (for instance, ROSE and CMISE) may be used over the association.

• After the association is established, ACSE is not used again until the association is released by the manager or agent.

1. ROSE:

• The Remote Operation Service Element (ROSE) is the ISO equivalent of remote procedure call.

• ROSE allows the invocation of an operation to be performed on a remote system.

• The Remote Operation protocol contains an invoke identifier for correlating requests and responses, an operation code, and an argument field for parameters specific to the operation.

• ROSE can only be invoked once an application association has been established.

• CMIP uses the transaction-oriented services provided by ROSE for all its requests and responses.

• CMIP also uses the error response facilities provided by ROSE.

1. Scoping:

• CMISE applies some additional powerful features to the operations that help further distinguish CMISE from SNMP. The M-GET, M-SET, M-ACTION, and M-DELETE services can be applied to more than one managed object through the application of what are termed scoping, filtering, and synchronization.

Figure - CMIP Protocol

• CMISE requests can be scoped to apply to a range of managed objects. Four levels of scoping can be applied, with the request being applied to:

1. The base object (as identified by the Distinguished Name)

2. Objects at the nth level subordinate to the object. The base object is termed to be at level 0 for this type of scoping

3. The base object and all managed objects to (and including) the nth level

4. An entire subtree - the base object and all subordinate objects on the containment tree

• Filtering:

• It is the application of a boolean expression to the request, with the request being applied to only those managed objects and attributes to which the expression is TRUE.

• The types of rules that can be applied to the request include equality, greater than or equal, less than or equal, and presence of an attribute.

• Other set and string based tests can be asserted, with combinations of the filters being grouped with the standard boolean terms of AND, OR, and NOT.

• Once all of the requested objects have been identified (meeting both the scoping and filtering criteria), the performance of the request can be completed based on one of two synchronization schemes: atomic or best-effort.

• Atomic operations are only performed when all managed objects pertaining to the scoping/filtering are able to successfully complete the requested operation.

• Best-effort synchronization will direct the request to all applicable managed objects. The requested operation is completed by as many objects that can comply.

1. Linked Replies:

• If the reply to a single request for a set of managed objects results in more than one managed object, all of these managed objects cannot be returned together in a single CMIP response PDU.

• The reason for this is that the structure of the CMIP response PDU only has a single field for containing object instance information.

• Since each managed object has its own instance information, each managed object must be returned in a separate CMIP PDU.

• In such a case, the CMIP Linked Reply PDU is used.

• The Linked Reply PDU provides a means of associating each of the multiple replies with the original request that generated them.

• Thus, a single CMIP Get Request PDU that uses scoping and filtering would result in zero or more CMIP Linked Reply PDUs being returned before a final CMIP Get Result PDU.

1. CMIS/CMIP:

• The Common Management Information Protocol (CMIP) is the OSI specified network management protocol.

• It provides an implementation for the services defined by the Common Management Information Service (CMIS) which allows communication between network management applications and management agents.

• CMIS/CMIP is the network management protocol specified by the ISO/OSI Network management model and is further defined by the ITU-T in the X.700 series of recommendations.

• CMIP models management information in terms of managed objects and allows both modification and performing actions on managed objects.

• CMIP also provides good security (support authorization, access control, and security logs) and flexible reporting of unusual network conditions

• CMIS services can be divided into two main classes: management association services and information transfer services.

• Furthermore, there are two types of information transfer services: management notification services and management operation services.