Abstract: A circuit emulation communication method includes the steps of: (a) converting user data received from a non-ATM medium into ATM cells, and transmitting the ATM cells to an ATM network; (b) converting ATM cells received from the ATM network into user data, and transmitting the user data to the non-ATM medium; (c) analyzing the user data received from the non-ATM medium in order to determine whether the user data coincides with non-communication pattern, and stopping a process of converting the user data into ATM cells carried out at step (a); and (d) generating non-communication pattern when any ATM cell is not received from the ATM network and sending the non-communication pattern to the non-ATM medium.

Abstract: In a method of communicating between an ATM-UNI and a LAN in a communication apparatus, which has an ATM-UNI interface and a LAN interface for performing communication between these interfaces via an ATM switch, transmission data in an ATM-cell format is received from a terminal connected to the ATM-UNI interface to a terminal connected to the LAN interface. The ATM cells are accumulated in a buffer memory provided in the ATM-UNI interface and assembled into a frame. Completion of reception of all ATM cells of one frame is recognized and it is determined whether there is margin for a transmission by referring to a status of vacancy of a LAN interface corresponding to the other party to communication. One frame of the ATM cells accumulated in the buffer memory is transferred to the LAN interface corresponding to the other party via the ATM switch in a case where there is margin for transmission. The ATM cells are converted into a frame at this LAN interface and the frame is sent to a LAN terminal.