Allied Telesis AT-MCF2012LC/1 - Manual (Page 20)

Chapter 1: Overview
20
Twisted Pair Ports
The twisted pair ports feature standard RJ-45 8-pin
connectors and operate at either 10 or 100 Mbps in either
half- or full-duplex mode. The ports use TIA/EIA 568-B-
compliant Category 3 or better cable for 10 Mbps operation
and Standard TIA/EIA 568-A-compliant Category 5 or TIA/
EIA 568-B-compliant Enhanced Category 5 (Cat 5e) cable
for 100 Mbps operation. The ports have a maximum
operating distance of 100 meters. For port pinouts, refer to
“10/100Base-TX Port Pinouts” on page 62.
The ports are IEEE 802.3u. compliant. They can
automatically set their speed and duplex mode with Auto-
Negotiation, which is the default setting. To disable Auto-
Negotiation and set the speed and duplex mode manually,
you must install the optional management module in the
chassis.
In order for Auto-Negotiation to work properly, the
networking device connected to a twisted pair port on the
module should also use Auto-Negotiation. Otherwise, a
duplex mode mismatch can occur. A twisted pair port using
Auto-Negotiation will default to half-duplex if it detects that
the port on the networking device is not using Auto-
Negotiation. If the other networking device is operating at a
fixed duplex mode of full-duplex, the result will be a duplex
mode mismatch with the port on the module operating at
half-duplex and the port on the networking device at full-
duplex. This can reduce network performance.
If you plan to connect a networking device that can operate
only in full-duplex mode to a twisted pair port on the media
converter module, you should disable Auto-Negotiation on
the port on the module using the optional management
module and set the speed and duplex mode manually.
Alternatively, you can reconfigure the port on the
networking device to Auto-Negotiation or, if it does not
support that feature, to half-duplex mode.
The twisted pair ports on the media converter module also
feature auto-MDI/MDI-X which automatically adjusts the
wiring configuration of a twisted pair port to either MDI or
MDI-X, depending on the wiring configuration of the end
node. This feature allows you to use a straight-through
twisted pair cable regardless of the wiring configuration of
the port on the networking device.