HI Guys, 

can you refer me to some resources which help me dimension the hardware for a setup.

Total users will be 20,000. What percentage should i assume for concurrent audio and video calls? What is the standard practice? How does this all map to the cpu, ram and storage etc. given that I will be storing the cdrs as well.

In the futute this setup should be scalable so that it should support 200,000+ users within a span of 6-8 months. What would be the ideal architecture?

Thanks,

Rizwan Khan