3Com CoreBuilder 7000 Operation Manual page 98

98 C 5: E
HAPTER STABLISHING
Transmitting Station
ATM Edge Device
The source station
is connected to an
Ethernet port of
the attached ATM
edge device
1 The virtual channel
starts at the ATM
edge device.
2 A VPI/VCI pair is
associated with
the virtual channel
by both the output
port of the edge
device and the
input port of the
switch.
ATM C
HANNELS
This section discusses the external link, established by signaling. For a
discussion of the internal links, which are established by routing, see
"Routing — Internal Links" on page 125 in the Management Guide.
A simple example of a virtual channel is shown as a dashed line in
Figure 35.
ATM Switch
1 2
VPI=0
VCI=32
The ATM switch has
3
been setup to associate
the specific VPI/VCI pair
on the input port with
another VPI/VCI pair on
an output port.
A VPI/VCI pair is
4
associated with the
virtual channel by both
the output port of the
switch and the input port
of the edge device
Figure 35 Virtual Channel Passing through ATM Network Devices
The figure shows three ATM devices: two ATM edge devices and an ATM
switch between them. The virtual channel begins at the left edge device,
passes through the switch and terminates at the right edge device. Two
external links of the virtual channel, shown as
ports of one device with input ports of the adjacent device; the internal
link within the switch, shown as
with the correct output port.
3
ATM Edge Device
4
5
VPI=1
VCI=44
The virtual channel
5
terminates at the
edge device.
The ATM edge
device associates
the VPI/VCI
information with
the destination
Ethernet output
port.
associates the input port of the switch
3,
Destination Station
The Ethernet
output port of
the edge device
is connected to
the destination
station.
and connect output
2 4