1. Make a MO call to a land line and stay on the line
2. Initiate another call from a different phone to the device under testing
3. Pick the 2nd call up without hanging up the 1st call
4. Switch to the 1st call without hanging up the 2nd call
5. End the 1st call
6. Make a MT call to the testing device and stay on the line
7. Make a 2nd MT call to the testing device
8. Pick up the 2nd MT call
9. Switch to the 1st call without hanging up the 2nd call
10. End the 1st call
11. Repeat step 1 - 10 for 3 times"