SEAMLESS CALL TRANSITIONS WITH PRE-ESCALATION PARTICIPATION CONFIRMATION

摘要

The local address book of a device can be crawled for contact information, which is communicated to an address clearinghouse. The clearinghouse can indicate whether a contact is a participant in a video calling service. If so, an indication can be stored locally indicating that the contact is a participant. Later, during an audio-only call with the contact, an option to escalate the audio-only call to a video call via the video calling service can be presented.