Hitachi US7070447-001 User Manual

Basic ATM Concepts

US7070447-001, Rev 01

11-3

The components of an Emulated LAN (ELAN) consists of the following:

❒

LAN Emulation Client (LEC) 

❒

LAN Emulation Configuration Server (LECS)

❒

LAN Emulation Server (LES)

❒

Broadcast and Unknown Server (BUS) 

The LAN Emulation Client (LEC) resides on the HiSpeed switch and acts as a 
proxy for devices connected to the Ethernet ports.  In addition, the LEC responds 
to any LAN Emulation Address Resolution Protocol (LE_ARP) requests from 
host machines on the network.  

The LAN Emulation Configuration Server (LECS) provides the LEC with the 
ATM address of the LAN Emulation Server (LES) to join an ELAN.  It also 
provides the LEC with configuration information.  The  LEC can connect to the 
LECS in one of three ways:

❒

Use ILMI

❒

Use the LECS well-known address:

 47007900000000000000000000:00A03E000001:00

❒

Use a Config Direct VCC of 0.17 (one for each ELAN)

The LES registers and resolves MAC addresses to ATM addresses within the 
ELAN.  The LES forwards the LEC response and helps the LEC locate the BUS, 
by responding to the LE_ARP request from the LEC.

The BUS forwards all broadcasts, multicast and unknown unicast traffic to all 
attached LAN Emulation Clients (LECs).