What is BER

BER (Bit Error Rate) is the probability that transmitted bit gets flipped (wrong value received).

Requirements

A PC
1 full duplex AUI card or 2 AUI network cards without full duplex requirement and 1 Half Duplex Reduction (HDR)
Linux where C programs can be compiled.
GNU R installed
Bertest installed
Mirror

Measurement conditions

Ensure there is only a dim lighting in the room. Otherwise, the measured value may be reduced.

Postscript / PDF / EPS / BIG png / SVG (Inkscape)

Connecting the boxes

If you are using 2 AUI network cards and HDR, then connect HDR and mark which card is the transmit one (T) and which the receive one (R).

Setup bertest for packetloss measurement.

Measurement

Choose output filename describing the measurement you are doing, we'll use example.dat for example. Let it run with output redirected into a file this way for a couple of minutes:

bertest <arguments> > rx_1.dat

Running GNU R

Now run ./analyze example.dat (replace example.dat with your datafile name). example.ps and example.pdf will be generated.

BER in PDF output

Display the resulting Postscript or PDF and go to page 12. There you can see filtered measurement of the BER. Read the higher value of the two. The unfiltered results are on page 2.

Evaluation

BER should be under 10^-9. If it's worse, then something is wrong with the electronics.

Measuring BER of Ronja Metropolis with Bertest