The specifications for LAN-LAN connections defined by the ATM Forum are called LAN Em ulation.
The LANEmulationClient (LEC) defines the implementation of this feature set in a LAN end device, thereby providing an interface for LAN emulation to the ATM network.
Any terminal device that wants to communicate over an emulated LAN must have a LAN Emulation Client. This is usually a program that runs on the end device and maps the LAN adapter card to the ATM end system in software. Since each adapter card in a LAN has a MAC address, the emulated LAN adapter card must be assigned a MAC address in the ATM end system. This means that an ATM end system has both an ATM address and a MAC address.