The entity hierarchy for the OSI Transport module is:

                            _Application (OpenVMS)
                           |
    Node___OSI_Transport___|_Local_NSAP______________Remote_NSAP
                           |
                           |_Port
                           |
                           |_Template

    The OSI TRANSPORT entity is the top-level entity in the hierarchy
    of entities belonging to the OSI Transport module.

    An OSI TRANSPORT APPLICATION entity stores information about an
    end user that is activated for receipt of an incoming connection
    request when the request contains that end user's name in its
    Destination Name field. The application-name refers to the
    application managed by this command.

    An OSI TRANSPORT LOCAL NSAP entity is automatically created for
    each NSAP address used by the osi transport entity. Local NSAPs
    are used primarily to group together remote NSAPs (see the OSI
    transport local NSAP remote NSAP entity). The nsap-address refers
    to the local NSAP managed by this command.

    An OSI TRANSPORT LOCAL NSAP REMOTE NSAP entity maintains
    the transport counters and generates events resulting from
    interactions between its superior local NSAP and a remote
    transport service. The nsap-address refers to the remote NSAP
    managed by this command.

    An OSI TRANSPORT PORT entity represents one end of a transport
    connection and maintains status information about that
    connection. Although the connectionless transport protocol
    does not create transport connections, ports are still used to
    maintain status information.

    On Tru64 UNIX, a port can also represent a listener, which is
    a passive endpoint awaiting connect requests from the remote
    transport service provider. Normally, ports exist only when
    OSI transport is enabled. However, the port that represents the
    session control listener (local transport selector 'DEC'0'H) is
    a special case. This port can exist even when OSI transport is
    disabled.

    The port attributes type, and for Tru64 UNIX direction, can be
    used to distinguish the various uses of ports. The port-name
    refers to the name of the port managed by this command.

    An OSI TRANSPORT TEMPLATE entity provides a collection of
    characteristics that supply default values for certain parameters
    that influence the operation of a port on a transport connection.
    One template, with the reserved identifier default, is
    automatically created when the osi transport entity is created.
    This template is used by default when a user does not specify
    a template identifier in a call to establish a connection.
    The default template is automatically deleted when the osi
    transport entity is deleted. Similarly, the initial values of
    the attributes in a template are the same as the current values
    in the default template. The template-name refers to the template
    managed by this command.

    For Tru64 UNIX, the only attributes that apply to CLTS are
    checksum, network service, and local nsap.