You can turn on Disable Call Waiting so active calls are not interrupted by incoming calls. You can enable this feature during a call and it will take effect right away. The calls will appear as Missed Calls in the List of recent calls (Windows) or History (Mac). Any new incoming calls ring busy (to the caller) or go straight to voice mail if you have this service.
1. Click More call options.
2. Select Disable call waiting.
Call Waiting is disabled is displayed beside More call options and a check mark appears beside the Disable call waiting on the More call options drop-down menu.