Allied Telesis AT-S21 - Manual (Page 37)

$70654#8VHU·V#*XLGH
3-5
'HVFULSWLRQ#RI
2SWLRQV
Enable or disable the port
Ports are enabled as a default. In case of a network problem, you may
want to disable a port to prevent problem packets from being
forwarded. Once the problem is fixed, you may enable the port again
to resume normal operation. You can also disable an unused port to
secure it from unauthorized connections.
Transmission mode
The 10Base-T/100Base-TX ports auto-negotiate as a default, while FX
ports are fixed at 100 Mbps. Depending upon what the connected
device supports, you may configure each switch port as follows:
Auto-negotiating: The port determines the connected device’s
configuration, 10 Mbps or 100 Mbps speed, full- or half-
duplex, and adapts automatically. This setting provides
flexibility so that you need not reconfigure the switch if you
change the type of device you are connecting to the port. If
you disable
Auto-negotiate by selecting Full-duplex
or Half-duplex , you can also select 10 Mbps or 100
Mbps .
Full-duplex: You may use this setting if the connected device
supports full-duplex; that is, transmit and receive
communications happen simultaneously.
Half-duplex: You may use this setting if the connected device
supports half-duplex; that is, transmit and receive
communications do not happen simultaneously.
Switching mode
Ports are set to store-and-forward as a default. With the available
switching options, you can optimize performance and enable error
checking.
Store-and-forward: With this setting, the port waits to receive an
entire packet before forwarding the packet to its destination;
the port forwards only those packets without errors. The port
automatically goes to the store-and-forward mode
automatically when data is exchanged between 10Base-T and
100Base-TX ports.
Cut-through (for 100 Mbps operation): This is available only at
100 Mbps transmission speed. The port starts to forward the
packet once the packet has exceeded the smallest size (64
bytes), therefore filtering fragment frames or runts. This
method provides low latency for forwarding frames and also
provides some network error protection.