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:

1The LEC must know the name of the ELAN it is to join.

The ELAN name is specified through the management software on the Switch.

2The 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.

3The 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.

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Avaya M770 M-ACCF/SF ATM Access Modules User’s Guide

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Avaya M-ACCF/SF manual Joining the Elan, LEC must know the name of the Elan it is to join, Locating the Lecs