3Com 5000 ATM manual Broadcast and Unknown Server BUS, Bridgeport-LEC

2-4CHAPTER 2: LAN EMULATION OVERVIEW

Broadcast and Unknown Server (BUS)

The Broadcast and Unknown Server is a multicast server that forwards multicast and broadcast traffic to LECs within a specific ELAN. The BUS also floods unknown unicast traffic to all LECs in the ELAN.

ATM Backbone Implementation of the LAN emulation components in the ATM SwitchModule LANE Backbone SwitchModule is illustrated in Figure 2-4.

Components

	ATM Backbone SwitchModule
Ethernet or FDDI	ATM OC-3 card
SwitchModule

AT M

n e t w o r k

LANE service

Virtual bridge (Vbridge)

Emulated LAN

Bridgeport-LEC(ELAN) (up to 64)

Figure 2-4ATM Backbone SwitchModule LANE Components

In addition to the standard LANE service components (see Figure 2-3), the ATM Backbone SwitchModule includes the following components:

Bridgeport-LEC

You define up to 64 bridgeport-LECs for each ATM Backbone SwitchModule. A bridgeport-LEC is both a standard ATM LEC that you assign to an emulated LAN and a bridgeport that you assign to a virtual bridge.