In India, VoIP to PSTN calls are prohibited for end users. So what vendors do are
- Caller place a request in a web interface to call a PSTN number
- The system places a call to the caller’s mobile/landline phone
- If caller picks the phone, then the system calls to callee and joins the calls
I am using a vendor who provides an API from where I can put the call request. I found them to build the system using Asterisks.
Do you have any ideas how to obtain this? I guess, conference bridge?