At one time or another I found an online calculator that would calculate the number of simultaneous VOIP calls you can have with the hardware selected. Now, I can’t find it. Anyone have any idea on what I’m talking about?
Here’s one for Wireless
http://www.connect802.com/voip_bandwidth.php
Here’s a few more including Erlang calculations depending on bw:
http://www.voip-calculator.com/calculator/
Here’s Asterisk Guru’s tools: