Avaya Configuring ATM Services Manual de usuario descargar pdf (Pagina 61)

Understanding ATM, MPOA, and ATM Router Redundancy Concepts

117374-B Rev. 00

1-35

LAN Emulation Server

The LES controls and coordinates LE client access to the emulated LAN. When

an LE client joins an emulated LAN, it registers its ATM address with the LES.

When the LES obtains the ATM address of the LE client, it also obtains the

client’s physical location (from the MAC address or route descriptor).

LE clients query the LES to obtain the ATM address associated with a specific

MAC address or route descriptor. After an LE client receives the ATM address of

the LE client it wants to reach, the individual clients communicate directly.

Broadcast and Unknown Server

To emulate a traditional LAN, the emulated LAN must provide the connectionless

data delivery of a shared network to its LE clients and be able to handle broadcast

and multicast data. The broadcast and unknown server (BUS) fulfills this

requirement by distributing all broadcast, multicast, and unknown traffic to and

from all LE clients on an emulated LAN.

For example, when an LE client sets up its initial configuration, it obtains the

MAC address of the BUS from the LES. Using this MAC address, the LE client

sets up a multicast send virtual channel connection (VCC) to the BUS. In turn, the

BUS registers the LE client as part of its emulated LAN.

To broadcast data, an LE client uses the multicast send VCC to transmit

information to the BUS. The BUS then retransmits the data, through multiple

point-to-point connections or one point-to-multipoint connection, to each LE

client on the emulated LAN.

Redundant LES/BUS

Bay Networks ATM routers support LAN emulation server (LES) and broadcast

and unknown server (BUS) redundancy. This redundancy reduces the risk of

network failure by overcoming a single point of failure in accessing the LES.

1 2 ... 56 57 58 59 60 61 62 63 64 65 66 ... 410 411

Sin comentarios

Avaya Configuring ATM Services Manual de usuario Pagina 61