The entity hierarchy of the XOT module is:

    Node___XOT____Port
                |
                |_SAP___Link

    The XOT entity represents the datalink interface to X.25.

    A XOT PORT entity provides information on each active XOT
    connection over TCP/IP, showing which X.25 protocol DTE entity is
    using a link.  Ports are created and deleted dynamically as X.25
    connections are requested.  There is one Port entity for each PVC
    or SVC connection.

    A XOT SAP entity specifies the point at which XOT gains access to
    the TCP/IP environment for purposes of listening for inbound XOT
    connections.  There can be a single XOT SAP entity to listen on
    any available IP interface; or one or more XOT SAP entities can
    be used to listen on specific IP interfaces.

    A XOT SAP LINK entity represents a remote system with which XOT is
    allowed to communicate.  In the case of an inbound XOT connection,
    there must be a LINK entity with a matching remote IP address and
    remote port number in order for XOT to accept the TCP/IP connection.
    In the case of an outbound connection, the LINK specifies the
    remote IP address and remote port number of the system with which
    to attempt the TCP/IP connection.