I have a number provisioned in twilio that does a simple call forwarding twiml bin.
The call is forwarded to a physical SIM number:
<Response>
<Dial>
+1-333-333-3333
</Dial>
</Response>
Then on handset I dialed *71,212-555-1212 where "212-555-1212" is a DIFFERENT number I have provisioned in twilio. This is called provisional forwarding at the carrier and it means that if the handset do not pick up after 4-5 rings it will forward it to the number I specified (212-555-1212).
If I call the first twilio number it forwards as expected and the handset ringing.
But then after the 4-5 rings the carrier call forward occurs and the call is terminated - the call is not passed onto the second twilio number. Provisional call forwarding fails.
Why is this happen ?
I think maybe twilio can tell this is a call loop and thinks it is a mistake or negative in some ways ? Or this is just a bug I have discovered and there is no meaning to it ?