How to encrypt a cell number?

Question

Telephony

Hello. It is necessary to make sure that when you try to get through to a mobile phone, you are redirected to some overseas server and from there the signal reaches the final address.
Example: a subscriber dials a mobile phone number, the signal goes to the server of a Russian operator, then it is redirected to a virtual server, and from there it goes back to the operator and to the end subscriber.
How to implement it? Is it possible to implement without using the Internet on end devices?

Answer 1

Your question is a bit "air", but nonetheless. You can redirect everything - if only the mobile operator would provide such a service. As a rule, in addition to the usual call forwarding (the one "which is controlled from the phone menu"), the operator does not provide extended services to individuals.
You write:

further redirected to the virtual server

This phrase sounds a bit wrong initially. They do not redirect to the server - there are concepts of the voice call termination path. That is, in other words, the operator's switch must decide where to which application to forward the call (and by what protocol).
Let's say you have an agreement with an operator:
You ask the operator to configure it so that when calling to a specific mobile number, signaling of a call to the called number for termination does not follow the standard path of the call (that is, to the mobile network), but "goes" to a specific gateway (for example, some SIP Gateway ), which has a direct connection with your so-called. "virtual server" (in other words, your application that understands SIP and can handle the call). Further, your application processes this call and again goes through SIP to the gateway, then the call enters the operator's switchboard and the switchboard "rings" to the number of the called subscriber (and thereby connects the caller and the callee, starting, along the way, the billing countdown).
Theoretically, this is how the so-called. precall announcements - when it is necessary to play a message (possibly interactive) before connecting, for example, to notify the subscriber that if he agrees (when connecting with the called subscriber), the cost per minute will be 1000 rubles - the caller can decide and give the command to continue or not.
As I said above, numbering is regulated - for commercial directions, operators provide special numbers, so the answer to your question is whether it is possible to "turn" off the path if the called number belongs to mobile numbering - then no (theoretically, of course, yes). If the called number belongs to a special numbering, then yes, it is possible that these services are provided (as a rule, for legal entities).