/mcpBackward Compatibility As mentioned above, new CTI Service parameter is added to maintain backward compatibility. Conference Enhancements The Conference feature of Unified Communication Manager has been enhanced with the following functions: • Allowing a noncontroller to add another party into an ad hoc conference. Applications can issue the lineGetCallStatus against a CONNECTED call of a noncontroller conference participant and check the dwCallFeatures before adding another party into the conference. The application should have the PREPAREADDCONF feature in the dwCallFeatures list if the participant is allowed to add another party. • Allowing multiple conferences to be chained. Be aware that these features are only available if the 'Advanced Ad-hoc Conference' service parameter is enabled on the Unified Communications Manager. When this service parameter is changed from enabled to disabled, the system no longer allows new chaining between ad hoc conferences. However, existing chained conferences will stay intact. Any participant who is brought into the ad hoc conference by a noncontroller before this change will remain in the conference, but they can no longer add a new participant or remove an existing participant. To avoid ad hoc conference resources remaining connected together after all real participants have left, Unified Communications Manager will disallow having more than two conference resources connected to the same ad hoc conference. However, using a star topology to connect multiple conferences could yield better voice quality than a linear topology. A new advanced service parameter, 'Non-linear Ad Hoc Conference Linking Enabled', lets an administrator select the star topology. A participant can use the conference, transfer, or join commands to chain two conferences together. When two conferences are chained together, each participant only sees the participants from their own conference, and the chained conference appears as a participant with a unique conference bridge name. In other words, participants do not have a full view of the chained conference. The system treats the conferences as two separate conferences, even though all the participants are talking to each other. The following figures shows how TSP presents a conference model in the case of conference chaining. A, B, and C are in conference-1, and C, D, and E are in conference-2. C has an ONHOLD call on conference-1 and an active call on conference-2. Figure 4: Conference Before Join C then does a join with the primary call from conference-1. For A, B, and C, the conference participants comprise A, B, C, and conference-2. For D and E, the conference participants comprise D, E, and conference-1. Cisco Unified TAPI Developers Guide for Cisco Unified Communications Manager, Release 15 and SUs 38 Features Supported by TSP Conference Enhancements