Allied Telesis AT-S100 - Manual (Page 50)

Chapter 2: Configuring the AT-S100 Software
50
To display the static port trunk assigned to port 12, enter the following
commands:
switch# configure terminal
switch(config)# interface ge12
switch(config-if)# show static-channel-group9
For more information about this command, see “STATIC-CHANNEL-
GROUP” on page 184.
Enabling
Backpressure
To maintain the orderly movement of data between the end nodes, an
Ethernet switch may periodically need to signal an end node to stop
sending data. This can occur under several circumstances. For example, if
two end nodes are operating at different speeds, the switch, while
transferring data between the end nodes, might need to instruct the faster
end node to stop transmitting data to allow the slower end node to catch
up. An example of this would be when a server operating at 100 Mbps is
sending data to a workstation operating at only 10 Mbps.
How a switch signals an end node to stop transmitting data differs
depending on the speed and duplex mode of the end node and switch
port. A twisted pair port operating at 100 Mbps and half-duplex mode
stops an end node from transmitting data by forcing a collision. A collision
on an Ethernet network occurs when two end nodes attempt to transmit
data using the same data link at the same time. A collision causes end
nodes to stop sending data. To stop a 100 Mbps, half-duplex end node
from transmitting data, the switch forces a collision on the data link, which
stops the end node. When the switch is ready to receive data again, the
switch stops forcing collisions. This is referred to as back pressure.
The syntax of this command is:
flowcontrol backpressure on|off
To active the backpressure feature on port 3, enter the following
commands:
switch# configure terminal
switch(config)# interface ge3
switch(config-if)# flowcontrol backpressure on
For more information about this command, see “FLOW CONTROL
BACKPRESSURE” on page 168.
Enabling Flow
Control
Flow control enables connected Ethernet ports (or interfaces) to control
traffic rates during congestion by allowing congested nodes to pause link
operation at the other end. If one port experiences congestion and cannot