LAN emulation (LANE)

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Definition of LAN Emulation (LANE) in The Network Encyclopedia.

What is LANE (LAN emulation)?

LAN Emulation, also known as LANE, is an Asynchronous Transfer Mode (ATM) technology that enables local area network (LAN) traffic such as Ethernet frames to be carried over an ATM network. LAN emulation (LANE) lets you use ATM as a backbone for connecting LANs.

LANE - LAN Emulation example
LANE – LAN Emulation diagram

How it works

Ethernet and ATM technologies are difficult to connect because ATM is a connection-oriented technology and Ethernet is a broadcast-based connectionless technology. Also, Ethernet frames and ATM cells are different in format and addressing.

For an ATM network to act as a backbone for connecting Ethernet LANs, it must support MAC-to-ATM address mapping. LANE converts variable-length Ethernet frames into fixed-length ATM cells for transmission over the ATM backbone. LANE services run on one or more network servers and map ATM endpoint addresses to non-ATM endpoint Ethernet MAC addresses. These services enable users on ATM networks to transparently access resources on Ethernet networks and vice versa. LANE clients run on bridges, routers, or servers and must reside on each end station of the emulated LAN. Each client has both a MAC address and an ATM address, which is a 20-byte network service access point (NSAP) address. A bridge or router connects the ATM network to the Ethernet network.

When a user on an ATM network wants to access a resource on the Ethernet LAN, the client sends an address resolution message (ARM) to the LANE server, which forwards the message to a bridge or router connected to the Ethernet network. If the bridge or router knows the destination MAC address, it acts as a proxy and forwards the message to the destination client; if it doesn’t know the destination MAC address, it relays the message to the broadcast unknown server (BUS), a LANE service that broadcasts the message to all stations on the Ethernet LAN.

LANE in Token Ring Networks

LANE can also be used for connecting Token Ring networks using an ATM backbone.