How to get the number from which the forwarded call came?

Question

Android

We have the following situation:
There is a SIM card with the number [phone]. It has forwarding "if not available" to the number [phone]. The SIM card with the number [phone] is active in the Android device. Some number calls [phone] and redirects to [phone]. Is it possible to find out the number from which the forwarding came from an Android device in any way (i.e. get the number [phone]) before picking up the call? By means of any available functions and methods of the SDK or something else.

Answer 1

Read about GSM and callerid.
There is a possibility to transfer your identifier instead of a hardwired number.
In reality, you often encounter this when making calls from ip telephony.
But what you are interested in is not transmitted to the subscriber device.
You can find out at the level of the logs of your PBX, but not on the phone.