Joining The Elan; Mapping Ethernet And Atm Addresses - Avaya M-ACCF/SF User Manual

Chapter 1 Overview

Joining the ELAN

Before a LAN Emulation Client (LEC) can transmit any Ethernet frames onto the
ATM network it must first join an ELAN. To join the ELAN:
1 The LEC must know the name of the ELAN it is to join.
The ELAN name is specified through the management software on the Switch.
2 The LEC must communicate with the LAN Emulation Server (LES) that is
serving that ELAN.
To communicate with the LES, the LEC must first locate the LES. The LEC can
find the ATM address of the LES in one of the following ways:
— If there is a LAN Emulation Configuration Server (LECS) on the network,
the LEC gets the address of the LES from the LECS.
— The way in which the LECS determines which LES the LEC needs to
communicate with, depends on the policy that the LECS is running. Refer to
the user guide that accompanies your LECS for more details of the policies
your LECS uses.
— If the network does not have a LECS, the LEC gets the LES address from the
management software on the ATM device.
3 The LEC must have a connection to the Broadcast and Unknown Server
(BUS).
When the LEC has joined the LES, the LES helps the LEC locate the Broadcast
and Unknown Server (BUS) associated with that ELAN.
Locating the LECS
Before the LEC can ask the LECS for the address of the LES, the LEC must first
locate the LECS as follows:
• The LEC can use a well known ATM address that is reserved for the LECS. The
well known address is pre-programmed into most LECS devices. The well
known address is: 47.00.79.00.00.00.00.00.00.00.00.00.00.00.A0.3E.00.00.01.00

Mapping Ethernet and ATM Addresses

Each device connected to an Ethernet port has one or more MAC addresses.
Each ATM device has a number of LAN Emulation clients, and each LAN Emulation
Client (LEC) has an ATM address. An example of this is shown in Figure 1.7.
12 Avaya M770 M-ACCF/SF ATM Access Modules User's Guide