Allied Telesis AT-S60 - Manual (Page 108)

Chapter 6: Port Parameters
Section I: Basic Features 108
High Priority - Indicates high priority has been assigned to the
port. All ingress tagged and untagged frames received on the port
are forwarded to the egress port’s high priority queue.
4 - HOL Blocking
You use this selection to prevent a frame from being forwarded to
a blocking or blocked port. For example, a blocking or blocked
port can be one that is receiving too many frames.
Press 4 to toggle between the following settings:
Enabled - Indicates HOL blocking is turned on. Frames sent from
this port are not forwarded to a blocked port.
Disabled - Indicated HOL blocking is turned off. Frames sent from
this port are not prevented from being forwarded to a blocked
port. This is the default.
5 - Back Pressure
You can use this selection only if the port or ports you specified
are operating at half-duplex mode. When you configure a port in
this mode and it has a frame that is pending transmission, the port
uses the JAM signal when its buffer is full to prevent the end node
from sending any more frames.
Press 5 to toggle between the following settings:
Enabled - Indicates back pressure is activated on this port. When
the port is receiving too many frames, the port sends a signal to
the end node to stop sending information.
Disabled - Indicates back pressure is not activated on this port.
When the port is receiving too many frames, the port does not
send a signal to the end node to stop sending information.This is
the default.
Note
The Auto setting is not available if you set a port’s speed and duplex
mode manually.
6 - Flow Control
Flow control applies only to ports operating in full-duplex mode.
The switch uses a special pause frame when its buffer is full to stop
the end node from sending frames. The pause frame notifies the
end node to stop transmitting for a specified period of time.
Press 6 to toggle between the following settings:
Auto - Indicates the port conforms to the flow control setting of
the end node. For example, if flow control is active on the end
node then flow control is active on this port. Also, if flow control is
not active on the end node, then flow control is not active on this
port. This is the default.