Abstract: The invention relates to a network emulating a local network, and particularly provides a communication cache management device that uses, e.g., an MPOA for efficiently transmitting LAN data within an ATM network, and a method therefor. A communication cache management method at an ingress communication client side includes the steps of: monitoring a data flow that is transmitted to an ingress communication server within a predetermined time period before a time-out of an aging timer after a shortcut has been set; re-starting an aging timer when there has been detected a data flow that exceeds a predetermined value; timing out the aging timer when there has been detected no data flow that exceeds the predetermined value; and timing out the aging timer when the contents of a response message to a communication address resolution request message do not permit a cache refresh.