Bell Telephone Laboratories

At&t Bell Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

American Telephone and Telegraph, Co.

Maurice N Ransom

Hugo J Beuscher

Ronald A Spanke

Scott C Knauer

Alan Huang

Wing N Toy

Sheng Ling Lin

Jay Henry O'Neill

Charles W Rutledge

Robert B Walford

John H Davis

A packet switching network that accommodates the appearance of multiple occurrences of packets addressed to the same destination are accommodated. The network includes a recirculating delay block within the switch, and an expander that includes a modest number of multiple appearances of the same address, followed by memories that accept the packets delivered at those multiple appearances, store the packets, and output the stored packets to the user, one at a time, in accordance with a set priority scheme.

Packet switching network

A communication method and packet switching network in which self-routing packets are communicated to a single-destination port of the switching network, a plurality of grouped destination ports or to two distinct destination ports after the modification by the switching network of the self-contained routing information within the packets. The packet switching network has a plurality of stages with each stage comprising a plurality of switch nodes, and the communicated packets can be of the single-destination, broadcast, or multiple-destination types of packets. The routing information within the packet comprises pairs of data bits with each pair associated with a stage of the switching network and with the value of the pair of bits determines the type of packet for the corresponding stage. Each switching node has two input and two output terminals, and a switch node in a particular stage is responsive to a single-destination packet received on an input terminal to communicate the packet to the output terminal designated by the value of the pair of bits for that stage. A switch node is responsive to a broadcast type packet to communicate the packet to both output terminals. In response to a split-destination packet, a switch node examines the next pair of bits of the routing information relative to the pair corresponding to the switch node in order to form two new single-destination packets from the split-destination packet. The routing information of the split-destination packet is only modified with respect to this next pair of bits.

Packet switching network with multiple packet destinations

A time division switching system which includes a central control, two time-multiplexed switching units each having a control distribution unit associated therewith and a plurality of interface modules each including a selected active control unit. Data words representing subscriber-generated information are conveyed between interface modules by a selected one of the time-multiplexed switching units designated as active. The active time-multiplexed switching unit also conveys control messages between each of the interface modules and the control distribution unit associated with the active time-multiplexed switching unit. However, the time-multiplexed switching unit designated as standby is also used to convey control messages between each of the interface modules and its associated control distribution unit. Each of the control distribution units routes received control messages to the interface modules via its associated time-multiplexed switching unit or to the central control. The central control directs system operation by transmitting and receiving control messages via the time-multiplexed switching units and their associated control distribution units.

Telephone switching control arrangement

A time division switching system having distributed control processors is disclosed. The distributed processors exchange control messages and cooperate in the completion of talking paths between subscribers. Each control message includes an address portion defining the destination for the control message and is transmitted to a time-shared space division switch on the same time multiplex lines that speech representations are transmitted. Control messages are routed by the time-shared space division switch to a control distribution unit where the address portion is interpreted. When the address portion defines a distributed processor which controls the time-shared space division switch, the control distribution unit transmits the associated control message directly to that processor. Alternatively, when the address portion defines one of the other distributed processors the control distribution unit transmits the associated control message to the defined processor via the time-shared space division switch.

Control information communication arrangement for a time division

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Naperville, IL, United States of America

Maurice N Ransom