The NSP module implements one of the protocols in the Transport
    layer described by the Digital Network Architecture.

    NSP performs the following functions:

    -  Enables the creation and destruction of transport connections
       used for sending messages within a network node and between
       network nodes.

    -  Manages the movement of expedited and normal data from transmit
       buffers to receive buffers, using flow control mechanisms.

    -  Breaks up normal data messages into segments that can be
       transmitted individually, and reassembles these segments into
       correct order after they have been received.

    -  Guarantees the delivery of data and control messages to a
       specified destination using an error correction mechanism.

1  –  Subentities

    The entity hierarchy for the NSP module is:

    Node___NSP____Local_NSAP___Remote_NSAP
                |
                |_Port

    The NSP entity is the top-level entity in the hierarchy of
    entities belonging to the NSP module.

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

    An NSP 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 local
    nsap nsap-address is the local NSAP associated with the specified
    remote NSAP. The remote nsap nsap-address is the remote NSAP
    managed by this command.

    An NSP PORT entity represents one end of a transport connection
    and maintains status information about that connection. A port
    is visible to the network only when it is assigned to a transport
    connection. The port-id is the port managed by this command.