Allied Telesis AT-9000/12POE Switch User Manual


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Chapter 10: Port Parameter Commands
176
FLOWCONTROL
Syntax
flowcontrol send|receive|both on|off
Parameter
send
Controls whether a port sends pause packets during periods of
packet congestion, to initiate flow control.
receive
Controls whether a port, when it receives pause packets from its
network counterpart, stops sending packets.
on
Activates flow control.
off
Deactivates flow control.
Mode
Port Interface mode
Description
Use this command to enable or disable flow control on ports that are
operating in full-duplex mode. Ports use flow control when they are
experiencing traffic congestion and need to temporary stop their link
partners from transmitting any more traffic. This allows them time to
process the packets already in their buffers.
A port that is experiencing traffic congestion initiates flow control by
sending pause packets. These packets instruct the link partner to stop
transmitting packets. A port continues to issue pause packets so long as
the traffic congestion persists. Once the condition has cleared, a port
stops sending pause packets to allow its link partner to resume the
transmission of packets.
The ports on the switch can both send pause packets during periods of
traffic congestion and stop transmitting packets when they receive pause
packets from their link partners. You can control both aspects of flow
control separately on the ports.
The RECEIVE parameter in the command controls the behavior of a port
when it receives pause packets from a network device. If receive is on, a
port stops sending packets in response to pause packets from its link