|
Requirements
- Tetrapolis (Inferno) not yet installed, separate modules
- A computer with 1 free full duplex network card
- Linux where C programs can be compiled.
- Bertest installed
|
|
|
Measurement conditions
Ensure there is only a dim lighting in the room. Otherwise, the measured
value may be reduced. |
|
Network card (NIC) setup
Set up full duplex and
10Mbps with autonegotiation disabled.
Full duplex hints.
The most used ones:
mii-diag -F 10baseT-FD eth?
mii-tool -F 10baseT-FD eth?
ethtool -s eth? duplex full
|
|
Get rid of any traffic into the NIC
- Kill all running dhcp daemons running on the interface (possibly
ps ax | grep dhcp to list them).
- Remove IP address (possibly
ifconfig eth? 0.0.0.0 )
|
|
|
Connecting modules
Connect the DUT to Network Interface Card (NIC) and connect Ronja
modules according to the picture. |
|
|
Running pktloss
If your input and output network card is eth0, run pktloss .
If eth1 is input and output, run pktloss eth1 . If eth1
is output and eth2 input, run pktloss eth1 eth2 . |
|
|
In such a case the output will be like this:
1102885167.075454000 100.000 100.000 1024 2224
1102885167.645578000 100.000 100.000 1024 2224
1102885168.215306000 100.000 100.000 1024 2224
1102885168.785415000 100.000 100.000 1024 2224
1102885169.355167000 100.000 100.000 1024 2224
1102885169.925561000 100.000 100.000 1024 2224
Second and third column show packetloss at 10MHz and 5MHz. |
|
|
|
Device with packetloss connected
In such a case the output will look like this:
1102885377.652586000 13.868 77.637 1024 2224
1102885378.222727000 14.649 80.372 1024 2224
1102885378.792451000 17.969 83.692 1024 2224
1102885379.362579000 17.188 85.157 1024 2224
1102885379.932404000 22.364 84.961 1024 2224
1102885380.502458000 15.528 79.883 1024 2224
1102885381.072232000 13.379 76.661 1024 2224
1102885381.642390000 15.918 75.196 1024 2224
1102885382.212091000 12.793 87.012 1024 2224
Second and third column show packetloss at 10MHz and 5MHz. |
|
|
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. |
|