Abstract: A networking node for interconnecting a local telephone switch such as a private branch exchange (PBX) with other such switches through other nodes, with respective internodal multichannel digital transmission links interconnecting the various nodes, provides service for both data and voice messages. The networking node provides at least two levels (one of which may be zero) of compression for voice messages and permits one of those levels to be preselected for all voice messages from the switch with which the node is associated to a predetermined one or more of the other nodes in the network. A look-up table is stored in memory within the node to control the assignment of particular levels of compression to particular destinations.