What i need to support 200 SIP calls at the same time?

How much in RAm in will need?
The processor at what speed?


The biggest question is: what are you doing with those calls?

Are they using an exotic codec?
Are they being recorded or accessing the HDD while they’re up?
Are they in a conference bridge?

RAM’s usually less of an issue compared to CPU capability.
HDD speed and CPU are important if everyone’s being recorded or constantly reading/writing from the HDD.