User Documentation

- 13 -
Auto MDI/MDI-X Connection
The Auto MDI/MDI-X function allows users to connect the Ethernet
Switch 10/100/1000BaseT(X) ports to any kind of Ethernet device,
without paying attention to the type of Ethernet cable being used for the
connection. This means that you can use either a straight-through cable
or cross-over cable to connect the Ethernet Switch to Ethernet devices.
Triple Speed Functionality and
Switching
The switch´s 10/100/1000 Mbps RJ45 ports auto negotiates with the
connected device for the fastest data transmission rate supported by
both devices. The Ethernet Switch is a plug-and-play device, so
software configuration is not required at installation or during
maintenance.
The half/full duplex mode for the RJ45 ports is user dependent and
changes (by auto-negotiation) to full or half duplex, depending on which
transmission speed is supported by the attached device.
Auto-Negotiation and Speed Sensing
The switch´s RJ45 ports independently support auto-negotiation for
transmission speeds of 10 Mbps, 100 Mbps, and 1000 Mbps, with
operation according to the IEEE802.3 standard.
This means that some nodes could be operating at 10 Mbps, while at the
same time, other nodes are operating at 100 Mbps or 1000Mbps.
Auto-negotiation takes place when an RJ45 cable connection is made,
and then each time a LINK is enabled. The switch advertises its
capability for using 10 Mbps, 100 Mbps, or 1000 Mbps transmission
speeds, with the device at the other end of the cable expected to
advertise similarly. Depending on what type of device is connected, this
will result in agreement to operate at a speed of 10 Mbps, 100 Mbps, or
1000 Mbps.
Note about possible lost of data packages in case of “Duplex
mismatching”
If the switch´s RJ45 port is connected to a non-negotiating device, then
the switch will set its port transmission speed same as the connected
device but is unable to correctly detect the duplex mode. As result the
port is set to the correct speed but is using always the half duplex mode
as required by the IEEE 802.3u standard in such cases. For correct
transmission the non-negotiating port has to be set to half-duplex mode
(speed either 10 or 100 or 1000 Mbit/s).