2-way calls, those that connect two separate parties or originate/terminate outside of a TwiML response, will have two related call "legs":
- One call leg connecting the SDK user endpoint to Twilio
- One call leg connecting the other party to Twilio
In a 2-way call like this, the "parent" call is the originating call - the first connection to Twilio. The second call leg spawned from the code is referred to as the "child" call.
The non-Client call leg (parent on inbound calls, child on outbound) is charged at our standard Programmable Voice per-minute rate, which varies based on the calling number, the destination, and number type. For a full pricing breakdown, please see our Voice Pricing site.