Getting caller phone number without for caller to pay fees

Asterisk Asterisk General
1

Hi all,

We need to build a server in order to retrieve the phone number of callers, without opening the line and hanging up.
The use case is:

  • the caller calls a phone number just to notify the server about something
  • the line is cut by the server upon the call reception (important: without for the caller to pay anything).
  • the server records the caller phone and the date of the call in database.
    End of use case.

Can that be done with an Asterisk analog card?
Must I buy a digital card?
Is there a VoIP based solution that can prevent me from buying a digital card?

Thank you for your help

2

All of these are possible and should be the natural result of simple dialplans.

However, your PSTN operator or SIP gateway operator may well consider this a breach of their fair use policies, as it is clearly denying them the revenue needed to operate their services.