The entity hierarchy for the OSAK module is:

    Node___OSAK____Application___Invocation
                 |
                 |_Port

    The OSAK entity is the top-level entity in the OSAK module
    hierarchy of entities. The OSAK entity is concerned with address
    management for applications that use the OSAK software for their
    communications requirements.

    An OSAK APPLICATION entity represents an OSI application and is
    created each time an OSI application that is running over the
    OSAK software opens an initiator or a responder.
    The entity also records information about the name and address of
    an application.

    For OpenVMS, an OSAK APPLICATION entity has zero or more application
    entity invocations, each represented by an OSAK APPLICATION
    INVOCATION entity (see below). In addition to recording information
    about the name and address of an application, it also records
    information that controls the way in which inbound association
    requests for that application are handled by the OSAK software.

    For OpenVMS, you should create an OSAK APPLICATION and an
    OSAK APPLICATION INVOCATION for each passive application that you
    want to run, identifying the application by its presentation
    address. Also, an OSAK APPLICATION entity is created automatically
    for an active application and deleted at the end of the connection.

    An OSAK APPLICATION INVOCATION entity represents one invocation
    of an application.

    For Tru64 UNIX, an OSAK APPLICATION INVOCATION entity is created
    each time an OSI application that is running over the OSAK software
    opens an initiator or a responder. You can use only the show
    command with the OSAK APPLICATION INVOCATION entity on Tru64 UNIX
    systems, and you cannot modify any of the attributes.

    For OpenVMS, an OSAK APPLICATION INVOCATION entity can be created
    in two ways:

    -  Automatically, each time an OSI application that is running
       over the OSAK software opens an initiator or a responder (as
       for Tru64 UNIX).

    -  Manually, when you use the create command.

    The create command creates a passive application, which becomes
    active only when your OpenVMS system receives an OSI call for
    that particular application invocation.

    Each OSAK PORT entity describes one association opened in an
    OSI application. A port is opened each time an application opens
    an initiator or a responder.