"C:\Program Files (x86)\Java\jre7\bin\java.exe" -jar psimulator2_frontend.jar
or just double click on psimulator2_frontend.jar...
Backend start from command line:
"C:\Program Files (x86)\Java\jre7\bin\java.exe" -jar psimulator2_backend.jar example.xml
In backend console I can see my backend port - which is by default 12000.
On frontend I clicked "Simulator" on top right corner and "Connect to server". (see Screenshot_2)
After succesful connection you can right click on computer or router and "Open telnet" (or I can you putty telnet client - localhost:+port from backend console (see Screenshot_3-6)).
In screenshots I send ping (1 ICMP echo packet) from pc2 to pc1.
Best regards