A method and apparatus for conferencing two or mores calls in an expandable telecommunications system. The system may include a plurality of nodes connected by an inter-nodal network such that the nodes communicate with each other by exchanging variable-length packets of information. At least one node in the system contains digital signal processing circuitry capable of conferencing the voice information from three or more callers interfaced with the system. Packets containing voice information from each conference participant are preferably transmitted via the inter-nodal network to the node having the requisite digital signal processing circuitry. This node performs a conferencing function on that information, packets the resulting conferenced information and transmits those packets via the inter-nodal network to the nodes interfaced with the conference participants.