The entity hierarchy for the X25 Protocol module is:

    Node___X25_Protocol____DTE___PVC
                         |
                         |_Group

    The X25 PROTOCOL entity is the top-level entity in the X.25
    Protocol module hierarchy of entities. The X.25 Protocol module
    operates the packet-level protocol interface to a PSDN, as
    defined by the CCITT and ISO specifications.

    An X25 PROTOCOL DTE entity describes a local DTE.

    An X25 PROTOCOL DTE PVC entity describes a permanent virtual
    circuit (PVC).

    An X25 PROTOCOL GROUP entity specifies a number of DTEs that make
    up a Closed User Group (CUG).