Indicates that the entity of the remote party of a call has changed due to a transfer or conference operation on remote endpoint's end.

There is no way to know the whether a transfer or conference causes the CallChanged event.

The Call Control API makes every effort to abstract the complexities of the underlying telephony protocol; however, one should consult the Call Control Feature Matrix to understand what Call Control actions and action parameters are valid for each of the four supported protocols. One can set installation and deployment guidelines based on the Call Control actions and action parameters that an application uses; the Call Control Feature Matrix makes developing such guidelines feasible.