I have successfully implement a APP to APP calling in iOS app using Twilio iOS SDK.
I have facing a problem in that Twilio SDK. I have explain with some step as below.
There are three user. User A, User B, User C
Step 1 : User A is calling to User B.
Step 2 : Now User C is calling to User A. User A is already talk with User B so what about User C. How can i identify busy state.