Alaxala AX2200S Series Configuration Manual page 210

13 Ethernet
Table 13-19 Connection specifications for transmission speed and duplex mode (full or
Settings on the remote device
Method
Fixed settings
Auto-negotiation
Legend N: A connection is not possible
(3) Auto-negotiation
Auto-negotiation is a functionality by which two devices negotiate to determine whether to
select full-duplex mode and whether to use flow control.
For details on the connection specifications for the Switch, see Table 13-19 Connection
specifications for transmission speed and duplex mode (full or half). Note that if the
connection conditions are not determined by auto-negotiation, the Switch attempts to
establish a connection until a link is established.
Auto-negotiation is not supported on 100BASE-FX.
(4) Flow control
The flow control functionality sends a pause packet to the remote device to instruct it to
temporarily stop sending frames so that received frames are not discarded when the
reception buffer on the switch is full. Conversely, when the switch receives a pause packet,
it regulates sending to the remote device. Note that flow control is available only in
full-duplex mode.
The Switch monitors the usage of the reception buffer, and sends a pause packet to the
remote device when sending on the remote device must be regulated. When the Switch
receives a pause packet, it regulates sending to the remote device. The flow control
settings for sending and reception are configured separately. Whether to enable or disable
flow control depends on these settings and the auto-negotiation result. When specifying
the flow control settings, make sure that the sending and receiving settings on the Switch
and the remote device do not conflict. For example, if you set
setting on the Switch, pause packet reception on the remote device must be enabled. For
details about how the operation mode is determined from the settings on the Switch and
remote device, see Table 13-20 Flow control for sending on the switch, Table 13-21 Flow
control for receiving on the switch, and Table 13-22 Flow control operation determined by
the auto-negotiation result.
For 100BASE-FX, no flow control is performed during auto-negotiation because
auto-negotiation is not supported.
188
half)
Settings on the Switch
Interface Fixed settings
1000BASE
full duplex
1000BASE N
half duplex
1000BASE 1000BASE
full duplex full duplex
1000BASE N
half duplex
1000BASE N
full duplex
Auto-negotiation
1000BASE
full duplex
N
N
N
1000BASE
full duplex
on for the pause-packet send