Hi,

  I've sucessfully completed an Openser 1.3.2 + Mediaproxy 1.9.1 + Asterisk 1.4 + CDRTool with freeradius telephony system.
  Asterisk is used only for voice mail and redirectioning calls.
  Every calls should pass through mediaproxy so that i can account them.
  The goal was to create a simple prototype of what could be a VoIP provider.
  Now i need to dimensioning this system to work with this requisites:

       - 10000 users;
       - 100 VoIP to VoIP calls simultaneously capacity;
       - 30 VoIP to PSTN calls simultaneously capacity;

  Can anyone point me some ideas of how can i design such a system (how many servers, how to distribute the services among them, etc.).
  I have this prototype mounted with VMWare, so i think that even making tests with sipp aren't going to be reliable.
  Thanks in advance,

                 Nuno