asterisk users - Apr 2014 - Parking, playback for at least 500 parallel calls and pickup one

Hi list,

we want to setup an Asterisk on Debian Wheezy.
There will arrive at least 500 parallel calls. All of them we set to parking.
Then the receive a playback.
After a certain time, we will pick up one caller. All the other calls will be
cancelled now.
Can Asterisk handle this or are there some hardcoded limits?
How much ressources you think will be needed for this solution (CPU, RAM, Disk
I/O)?

Best regards,
Julian Santer