Active Speaker Notification - AudioCodes Mediant 1000 User Manual

SIP User's Manual
When issuing a Media Service on the Control Leg, it affects all Participant Legs in the
conference, e.g., play an announcement. When issuing a Media Service on a Participant
Leg, it affects the specific leg only.
Figure 10-4: Applying Media Services on a Conference -- SIP Call Flow

10.1.2.5 Active Speaker Notification

After an advanced conference is established, the Application Server can subscribe to the
gateway to receive notifications of the current set of active speakers in a conference at any
given moment. This feature is referred to as Active Speaker Notification (ASN) and is
designed according to the MSCML standard. Notifications provide information on the
number of active participants and their details.
The notifications are sent unsolicited at specific intervals requested by the application and
only when a change in the number of active conference speakers occurs. If a change in the
speakers list occurs, the server issues an INVITE to the specific SIP UA, and then transfers
the call to the UA.
Version 5.2 455
10. Media Server Capabilities
September 2007