LattisLink 2800A 10BASE-T Workgroup Concentrator User’s Guide
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Indicators and Switches
A-2
893-541-A
MDI-X/MDI Switch
The LattisLink 2800A 10BASE-T Workgroup Concentrator allows you to
configure Port 1 as an MDI or MDI-X port. The abbreviation MDI stands for
Media Dependent Interface, and is specified by the IEEE 802.3i 10BASE-T
Standard to be the electrical and mechanical interface to the UTP wire. An MDI
port transmits out to the UTP wire on pins 1 and 2 (pair 2 of the 4-pair cable),
and receives from the UTP wire on RJ-45 pins 3 and 6 (pair 3 of the 4-pair UTP
cable).
For two 10BASE-T devices to communicate, the transmitter of each device
must connect to the receiver of the other device. The reversal of the transmit
and receive assignments is called a crossover function. Every 10BASE-T link
segment requires a crossover function, and it can be implemented in one of two
ways:
s
Externally, with a crossover UTP cable that reverses the transmit and
receive wire-pairs at the RJ-45 connector on one end of the UTP cable (see
Figure A-2)
10BASE-T
port LEDs
(16 pairs)
Link
green
The port is connected to
another powered 10BASE-T
port whose signaling meets
the requirements for an IEEE
802.3i 10BASE-T device.
Part
yellow
The port has been
autopartitioned because of an
excessive number of
consecutive collisions or an
excessively long single
collision signal.
Table A-1. Model 2800A Workgroup Concentrator
LEDs (continued)
Type
Label
Color
Meaning
Summary :
Every 10BASE-T link segment requires a crossover function, and it can be implemented in one of two ways: s Externally, with a crossover UTP cable that reverses the transmit and receive wire-pairs at the RJ-45 connector on one end of the UTP cable (see Figure A-2) 10BASE-T port LEDs (16 pairs) Link green The port is connected to another powered 10BASE-T port whose signaling meets the requirements for an IEEE 802.3i 10BASE-T device.
Tags :
10baset,port,utp,cable,crossoer,mdi,wire,deice,interface,function,pins,leds,4pair