Allied Telesis AT-FS238b/2 - Manual (Page 22)

Overview
12
Twisted Pair Port
The AT-FS238a/x and AT-FS238b/x Series Bridging Converters have one
10Base-T/100Base-TX twisted pair port. The twisted pair port features a
RJ-45 connector.
Port Speed
The twisted pair port is compliant with the 10Base-T and 100Base-TX
standards and is capable of either 10 Mbps or 100 Mbps operation. You can set
the port speed manually or, since the port is IEEE 802.3u Auto-Negotiation
compliant, you can let the bridging converter set the port speed automatically.
With Auto-Negotiation, the speed of the port is set automatically by the
bridging converter after it determines the speed of the end-node connected to
the port. Auto-Negotiation is designed to ensure that the port on the bridging
converter and the end-node are operating at the same speed and that they are
communicating at the highest possible common speed of the devices.
Duplex Mode
Duplex mode refers to how an end-node receives and transmits data. If an
end-node can receive or transmit data, but not both simultaneously, the end-
node is operating in what is referred to as half-duplex mode. If an end-node
can both receive and transmit data simultaneously, the end-node is said to be
operating in full-duplex mode. Naturally, an end-node capable of operating in
full-duplex can handle data much faster than an end-node that can only
operate in half-duplex mode.
The twisted pair port on the AT-FS238a/x and AT-FS238b/x Series Bridging
Converters can operate in either half-or full-duplex mode. It is IEEE 802.3u-
compliant and uses Auto-Negotiation to set the duplex mode setting for you
automatically. If desired, Auto-Negotiation can be disabled and you can set
the duplex mode manually.
Note
In order for a twisted pair port on the AT-FS238a/x and AT-FS238b/x
Series Bridging Converters to successfully Auto-Negotiate its duplex
mode with an end-node, the end-node should also be using Auto-
Negotiation. Otherwise, a duplex mode mismatch can occur. The twisted
pair port, using Auto-Negotiation, will default to half-duplex if it detects
that the end-node is not using Auto-Negotiation. This will result in a
mismatch if the end-node is operating at a fixed duplex mode of full-
duplex.