Ronja Twibright Labs

Half duplex packetloss measurement for Ronja 10M Metropolis

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Packetloss measurement for Ronja 10M Metropolis device connected to AUI with 2 half duplex cards and Half Duplex Reduction



  • 1 computer
  • 2 AUI network interface cards (NIC)
  • 1 Half Duplex Reduction (HDR)
  • 1 Ronja 10M Metropolis device or 1 AUI Forte

AUI trasceiver

Force AUI transceiver in both cards.


Naming convention

In the following, we'll call the interfaces eth0 and eth1. They may be named different, especially on different operating system than Linux.

Connecting device

Insert the half duplex reduction (HDR) into network card AUI connectors so that male "T" goes into eth0 and male "R" into eth1. Connect the device to the HDR.

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

Device setup

Connect components together this way.



Set up a permanent ARP table entry on interface eth0, for IP address and MAC address from the paper (Linux: arp -i eth0 -s <MAC address from the paper>)

Routing table

If the kernel hasn't already done it add a routing table entry for IP address to interface eth0 (Linux: route add eth0)


Download and run an ethernet or IP packet sniffer on eth1. The sniffer must set the interface to promiscuous mode ( tcpdump or Wireshark does). Run the sniffer on interface eth1 (Linux: download and install tcpdump or Wireshark , then issue

tcpdump -i eth1
or run Wireshark on eth1.) Leave the sniffer running.



Take a block of packets and manually count how many are double (not lost) and how many single (lost). Calculate packetloss in percent (%) as 100*single/(double+single).

An expected information missing here?