Abstract: To perform call control signaling between a user and a telecommunications switching network (and end-to-end between users), a portion of the multiplex overhead of a multiplexed data stream is formatted so that it includes the call control signaling. This in-band signaling is actually in the multiplex overhead and not in the user data as in standard multiplex formats. At nodes of the network and at user devices connected to the network, the call control signaling is extracted from the overall data stream and is processed to selectively generate new and responsive call control signaling for completing the signaling operations. The invention is useful over the entire multiplex hierarchy.