Target audio bitrate and max bitrate for outgoing audio streams.
Allows the Director to set their outbound audio bitrate to be shared with guests at something like 160-kbps, while having the guests still be able to share their audio between other guests at the default audio bitrate of around 32-kbps. If the guest sets the audio bitrate (&proaudio=1 or &audiobitrate=200) on the view link will override the publisher's &outboundaudiobitrate parameter.
