Abstract: A distributed control arrangement for a multi-mode circuit-switching or circuit- and packet-switching system avoids disadvantages attendant to a centralized control center and offers flexibility in the sourcing of communication-routing information. The switching system communicatively interconnects a plurality of communication endpoints, such as PBXs, and includes a plurality of circuit-switching units interconnected with each other and with the endpoints by at least one communication medium. Control is effected through a plurality of logical links of the LAPD communication protocol, one of which extends through the medium between each pair of adjacent units and of adjacent unit and endpoint. Each unit is responsive to receipt of a messeage that specifies a route of a circuit-switched communication path through the system, including through the receiving unit.

Abstract: Apparatus for and a method of inserting circuit switch information and packetized data into different time slots of a time division multiplexed bus. A memory having a location individual to each time slot is written with information specifying whether the time slot individual to each location is to serve circuit switch information or packet data. The readout of each memory location during the occurrence of it's associated time slot controllably effects the application of either the circuit switch information or the packet data to the bus. Packet data can be inserted into each time slot not currently being used by the circuit switch. A special information bit is inserted into each time slot to specify whether the remainder of the bits of the time slot represents circuit switch or packet information. The information bit is used by receiving apparatus to steer the bits of each time slot to either a receiving circuit switch or a receiving packet switch.