3com 5000 ATM User Manual
2-8
C
HAPTER
2: LAN E
MULATION
O
VERVIEW
Data VCCs
Data VCCs consist of the following three types:
■
Data Direct VCC — A bidirectional point-to-point VCC set up
between two LECs that want to exchange data
between two LECs that want to exchange data
■
Multicast Send VCC — A bidirectional point-to-point VCC between
the LEC and the BUS
the LEC and the BUS
■
Multicast Forward VCC — A unidirectional VCC from the BUS to
the LEC; typically, a point-to-multipoint connection from the BUS to
multiple LECs
the LEC; typically, a point-to-multipoint connection from the BUS to
multiple LECs
Figure 2-8 illustrates the function of the three basic types of Data VCCs
in ATM Backbone SwitchModule LAN emulation.
in ATM Backbone SwitchModule LAN emulation.
Figure 2-8 Data VCCs in ATM Backbone SwitchModule LAN Emulation
ATM Backbone
SwitchModule
SwitchModule
Broadcast and Unknown
Server
(BUS)
Server
(BUS)
ATM LEC
Data Direct VCC
Multicast Forward VCC
Multicast Send VCC
Bridgeport-
LEC
LEC