Requirements

A computer with 1 free full duplex network card or 2 free network cards
A Half Duplex Reduction (HDR)) if there are two network cards and one device under test (DUT).
Linux where C programs can be compiled.
Bertest installed

Network card (NIC) setup

If you are going to use just one NIC, set up full duplex. Full duplex hints.

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)

Connect the device

With 1 full duplex card, connect the device to that card
With 2 network cards and half duplex reduction (HDR), connect HDR into the 2 NICs and tested device into the HDR. Transmitting card is the one with "T" end of the HDR and receiving with "R"
With 2 network cards you need 2 tested devices (Twisters or AUI Forte's) and plug one into each card.

Running pktloss

Run pktloss under root with following parameters in the directory where bertest is unpacked:

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

No device connected

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