ATM LAN Emulation Server
LEC builds a virtual circuit to LES and communicates with it via the LUNI (LANE User-Network Interface)
LEC registers its MAC addresses to the LES
LES transfers data frames between MAC addresses and VCs
BUS is used to deliver multicast and broadcast messages, BUS receives them and delivers them to the recipients by using either Multicast Forward VCCs or a Multicast Send VCC
LEC establish the multicast connections