Softphone.Pro 2.3 doesn't support switching between several active calls, but you can choose one of call waiting options:
- Reject new call and send 486 Busy Here SIP message. This is default option.
- Hold on new call until you complete your current call.
You can see incoming call notification window with the both options above.
1. Open Settings - SIP Settings section:
2. Enable Enable call waiting checkbox:
3. You can also enable Play call waiting tone checkbox. With this option enabled Softphone.Pro plays short tone when new call is received: