Early media refers to audio and video that is exchanged before a call is accepted by the recipient. Early media generated by the caller include voice commands or dual-tone multi frequency (DTMF) tones to activate interactive voice response (IVR) systems. Early media generated by the call recipient include ringback tones, announcements, and requests for input.

Enhanced early media support in Office Communications Server 2007 R2 enables a caller to hear a ringback tone generated by the call recipient’s mobile phone. This is also the case in team call scenarios, where a call is routed to two team members, one of whom has configured simultaneous ringing for his or her mobile phone. Enhanced early media support also enables call connectivity checks while a call is ringing rather than only after it is connected, as was the case in Office Communications Server 2007.