The HRIM provides the CX-1500 and CX-1540 with the integrated capability of performing Ethernet hubbing and router functions, allowing the legacy Ethernet LAN's to be integrated onto an ATM Network. The HRIM is a compact subassembly that occupies two slots in the chassis. The HRIM converts the IP traffic into ATM cells, terminates eight Ethernet facilities, conducts Ethernet hubbing-router functions, and performs the necessary ATM cell adaptation (AAL5) to the switching fabric. In the transmit direction the process is reversed.