Abstract: A distributed control apparatus and method is disclosed to maintain the network stability in a packet switching local area network under changing traffic load conditions, by controlling the size of the packets transmitted by each node. The invention monitors the present information flow rate in the network and computes an average packet length which it then uses to adjust the size of the variable length data field in each message frame. In this manner, network flow control can be achieved without forcing data terminals connected to the nodes of the network to adjust their speed. The invention is applicable to a wide variety of local area network protocols for both ring and bus architectures.

Abstract: Up to k (e.g. 4) slot interchange memory/switch modules operate under common control to provide varied time interchange connective pairing associations between space divided telephone and data lines and time divided channels of digital trunks. A high scanning rate combined with dot-OR'ed (commoned) busing of addresses and outputs of all interchange modules permits in-service expansion of interchange switching capacity, from the capacity of 1 module to that of k modules, with minimal re-work of existing circuits and common control programs. The interchange slot locations of the aggregate array are thereby linkable in paired randomly ordered time interchange associations, over the entire addressing range of the aggregate. Additional interchange spaces are available in each switch module for interchanging activity bits in association with information traffic. These bits are useful for companding control, echo cancellation, TASI and network routing.