Abstract: A flow in a network is identified and handled by using a virtual host address. A packet is received at a switch with a first virtual host address as its destination address. If the packet is the first packet of a flow received by the switch, then a second virtual host address is determined by the switch. The first virtual host address is stored in a packet forwarding table correlated with the second virtual host address. A subsequently received packet of the same flow has the same first virtual host address as its destination address, and is forwarded to the second virtual host address in accordance with the packet forwarding table.

Abstract: A large high capacity switch is provided for a communication network which is constructed from a network of smaller switches. Data is fragmented into fixed sized cells and the cells of a traffic flow are aggregated by grouping cells to form larger yet uniform units of information transfer. The groups are transmitted synchronously and in parallel to increase the effective bandwidth of information transfer.

Abstract: A large high capacity switch is provided for a communication network which is constructed from a network of smaller switches. Data is fragmented into fixed sized cells and the cells of a traffic flow are aggregated by grouping cells to form larger yet uniform units of information transfer. The groups are transmitted synchronously and in parallel to increase the effective bandwidth of information transfer.

Abstract: A flow in a network is identified and handled by using a virtual host address. A packet is received at a switch with a first virtual host address as its destination address. If the packet is the first packet of a flow received by the switch, then a second virtual host address is determined by the switch. The first virtual host address is stored in a packet forwarding table correlated with the second virtual host address. A subsequently received packet of the same flow has the same first virtual host address as its destination address, and is forwarded to the second virtual host address in accordance with the packet forwarding table.

Abstract: A large high capacity switch is provided for a communication network which is constructed from a network of smaller switches. Data is fragmented into fixed sized cells and the cells of a traffic flow are aggregated by grouping cells to form larger yet uniform units of information transfer. The groups are transmitted synchronously and in parallel to increase the effective bandwidth of information transfer.

Abstract: Apparatus and methods used in a network for translating names into network addresses. Source nodes in the network receive names and have name caches for translating the names; destination nodes have local name tables containing correspondences between names and the network addresses served by the destination node. Them is further a name server accessible to the nodes which contains current correspondences between names and network addresses. A name is translated by first presenting it to the name cache in a source node; if there is no entry for the name in the cache, name cache maintenance code in the source node obtains information about the name from the name server; once there is an entry, the name is translated and a call set up message containing the name and the network address is sent to the destination node, which checks whether the name and network address are its local name table. If they are, the destination node returns a call complete message to the source node.

Abstract: Methods and apparatus for employing a communications system with actively connects communicating entities to mediate transactions. Disclosed are general methods and apparatus for mediating transactions, methods and apparatus permitting information from one transaction to be used in other transactions, and methods and apparatus for performing credit card transactions in which the vendee need not disclose his credit card to the vendor. An implementation of a system for performing credit card transactions in a stored program-controlled telephone switching network is also disclosed.

Abstract: Apparatus and methods for time multiplexing a resource among a plurality of entities at average rates and with deterministic delays between accesses to the resource by an entity. An entity accessing the resource receives a time slot on the resource; a fixed number of time slots constitute a frame. Each entity receives a fixed allocation of time slots in the frame. When an entity has work for the resource to do, it receives access to the resource for a number of slots in each frame equal to the lesser of the number of slots required to do the work and the number of slots in the allocation. A rate-controlled server is disclosed which defines a frame and allocations therein, as well as a hierarchy of servers which combines rate-controlled traffic with best effort traffic. In the hierarchy, a rate-controlled server activates a round-robin server when the entities served by the rate-controlled server do not require all the slots in a frame.

Abstract: A universal protocol data receiver is disclosed which is capable of receiving data streams in character mode and block mode, providing flow control and error detection and correction. The receiver is divided into two stages separated by a first-in, first-out buffer register. The first stage handles flow control and error processing as well as initialization. The second stage handles interfacing with the data utilizing mechanism and flow control acknowledgements. The FIFO buffer is divided into two parts by a movable barrier which limits the access of the second stage. The barrier permits error processing by hiding incoming blocks of data behind the barrier until processing is complete. Both a hardware and a software implementation of the receiver are disclosed.

Abstract: An electronics space-division packet switch is disclosed in which each switch crosspoint includes digital logic capable of resolving simultaneous contentions for the source output buss medium. In particular, a bit-by-bit comparison of priority codes disconnects all switches but the one with the highest priority from the output buss.This extremely simple crosspoint switch structure makes possible extremely large space-division packet switches in very compact physical form, using large scale integration techniques.

Abstract: In a local data distribution network configuration a plurality of bidirectional data distribution busses are each connected to a bus master control circuit at a terminal end of the bus. Connected to each of the data distribution busses are a plurality of passive outlets to which intelligent connectors or stations may be connected. Each station has a unique address and is utilized for individually coupling data processing devices to the bus. Grouped pluralities of the bus master control circuits are included within a bus termination hub facility. Data from any of the bus master control circuits may be transferred by the bus termination hub via a data trunk as part of a star type configuration, to a central switching circuit such as a virtual circuit switch. Direction of data flow on each of the bidirectional busses and periodic temporary synchronization of the stations is controlled in response to signals transmitted to the bus by the bus master control circuitry associated with that bus.

Abstract: A status report of equipment in a telecommunications network is transmitted automatically from the equipment to the network maintenance center. The status report includes information such as the serial number of the equipment and its location. Based on such a status report, the network maintenance center can keep up-to-date records of where equipment is located, how the equipment is interconnected with other components, and whether that equipment is functioning correctly. Furthermore, a portable test device can be used by a maintenance person to read the status report transmitted on the line and thereby determine the end points of any transmission line.

Abstract: A first-in, first-out queue has a random access memory (RAM) for storing a plurality of information words, seriatim. A controller is used to insure that only after a complete message, comprising the information words, has been received will a word of that message be read out. Three pointers are used to effect this result. A read pointer addresses the location in the RAM from where a word may be read. A write pointer addresses the location in the RAM where a word may be entered. A third pointer addresses the location in the RAM where the last word of a complete message is stored.

Abstract: Messages, comprising a plurality of multiplexed packets of information bits, are received on a transmission line from each of a plurality of sources. All packets from the same source have the same source identification number and are stored in one of a plurality of first-in, first-out queues. After at least one of said packets has been stored, it is available for being read out from the first-in, first-out queue. In order to insure that each queue has an equal chance of being accessed by a utilization means, the status of all queues is registered in a status register.

Abstract: The information in the header portion of a data packet, which header includes the old module and channel numbers, is used to access locations in a random access memory which contain new module and channel numbers or words that identify the packet routing. To convert the "virtual" address defined by the old module and channel numbers to a physical address, the module number accesses a memory word which is combined with the channel number to produce a single physical address number. When the information stored in the memory is to be changed, the header has special module and channel numbers and the following data includes a "write" command word, address data and information data. The special header words access a memory word which enables the writing of the information data into memory locations selected by the address data. A "read" command word in the packet inserts the word accessed by the address data into the packet.

Abstract: A digital data transmission system comprising a plurality of interconnected switching units, each such unit having connected thereto at least one transmission loop, and each such loop having at least one digital device attached thereto. The system provides controllable buffering of digital data thereby allowing digital devices having different data transfer speeds and storage capabilities to communicate asynchronously. The system allocates communication resources upon request but only creates actual communication paths when the requesting device is transmitting data. Thus system resources need not remain committed between bursts of data.