Nope. There is no limitation of using ASTPP. You can use it anywhere.
It can be used in small scale as well as large scale carrier setup.
You just need to have system with above defined OS and then you will be able to setup ASTPP on that.
It is strongly recommended that ASTPP be deployed on the Linux distribution CentOS version 7.x or Debian version 8.x
CentOS 7.X OR Debian 8.x,
4GB RAM (8 or 16gb is highly recommended for better performance),
40gb Hard Drive,
We recommend to use high configuration hardware to get better performance.
Yeah, It can work on Virtual servers.
That is purely depends on hardware which you will use. More Hardware resource can give more concurrent calls.
It supports only MySQL (PostgreSQL support will be added in future release).
ASTPP provides update.sh script with its source just run that script to update your source.
Enable short_open_tag in php.ini and then restart apache.
Make sure you have configured your IP in Sip Profile and your registration request is reaching to server.
Default sip profile must be loaded in FreeSWITCH
Please check your database credentials. ASTPP uses /var/lib/astpp/astpp-config.conf file for database connection.
Configure your customer IP under Customers -> IP Settings
No, CDRs report will only record of current day. If you want to see record of previous days record then you need to search.