In an embodiment, a user equipment (UE) participating in a server-mediated communication session maintains an identifier of the session and a list of UEs that are currently participating in the session. The UE determines to suppress its participation level in the session, and configures a member update message to include the identifier and to indicate the suppressed participation level of the UE. The UE transmits the configured member update message to each other UE currently participating in the session. In another embodiment, the UE receives a request to modify one or more of a given set of control parameters associated with the session. The UE determines whether the UE belongs to a subset of UEs that are currently participating in the session and to which permission to modify the given set of parameters is restricted. The UE selectively grants the received request based on the determination.