A user terminal (10) initiates an internet protocol using session initiation protocol to interconnect a number of user terminals (11-13) in a conference call. Signaling connections (41, 42, and 43) are established between one user terminal and each of the plurality of user terminals. Common bearer formats are negotiated among the plurality of user terminals (113). If a common bearer format exists (115), the conference bridge is established for data (voice) transmission (127).