Abstract:
A cell having an attribute of a point-to-multipoint connection is distributed to each of a number of subscribers using a point-to-multipoint connection distributing switch to be provided in parallel with a point-to-point connection, concentrating and distributing switch. Therefore, a hardware configuration can be simply established. Besides, both a point-to-point connection, and a point-to-multipoint connection can be made only by switching a cell to each switching unit, and a software configuration can thus be simplified.
Abstract:
An information processing system includes a simplex system and a duplex system in which at least two data transmitting systems are provided each capable of being an act system or a standby system. Each data transmitting system has a data acquiring unit. The simplex system includes a controller for controlling a selector to switch between the systems. When in a standby condition, the data acquiring unit of the respective data transmitting system in the duplex system issues an access request signal to a switching signal generating unit provided in the controller of the simplex system to request that the output of the selector be switched from the act system to the standby system in the duplex system. Upon receipt of the access request signal from the data acquiring unit in the standby system, the switching signal generating unit switches the selector to the standby system. As a result, status data acquired by the data acquiring unit in the simplex section is output to the data acquiring section in the standby system. The duplex system uses the status data to make a diagnosis of the standby system for its normality.
Abstract:
A virtual channel converter converts a virtual path identifier and a virtual channel identifier, e.g. in a twenty-eight (28) bit frame, attached to the header part of an incoming ATM cell on an input highway to an ATM switcher to identifiers to be attached to an outgoing ATM cell on an output highway capable of fully supporting all the combinations, two hundred fifty-six (256) for example, of a virtual path identifier and a virtual channel identifier no matter where the virtual path identifier and the virtual channel identifier are located in the twenty-eight (28) bit frame. The virtual channel converter comprises a plurality of identifier comparator units and a controller. Each of the identifier comparator units has an input identifier memory for storing an identifier attached to an ATM cell and a comparator for comparing the identifiers of an incoming ATM cell with the identifiers stored in the input identifier memory. The controller instructs respective input identifier memories to store all the values of identifiers attached to incoming ATM cells from a user to a switcher on a one-to-one basis.
Abstract:
A supervision control system for an ATM cell switching system counts the number of cells transmitted from a subscriber in a predetermined duration unit, attaches a sign to the cells when the counted value exceeds a predetermined value, and discards the cells to which the sign is attached when a buffer does not have enough capacity during a cell multiplexation.
Abstract:
A control data transmission system controls an electronic switching system with few signal lines. Control data are split into a plurality of fixed-length bit blocks. The control data sequence number specification signals identify the fixed-length bit blocks. The control data sequence number specification signals are paired with corresponding control data signals carrying the contents of one of the fixed-length bit blocks and a control data validity specification signal for validating transmission of the control data. The control data sequence number specification signals are decoded and the contents of respective bit blocks carried by the control data signals are stored according to the decoding result and the control data validity specification signal. When the contents of the fixed-length bit blocks carried by the control data signals for one unit of control data are stored, the control data are analyzed.
Abstract:
It is determined whether or not a passing cell is a cell to be measured. If yes, a signal synchronous with the passing cycle of the cell is generated by a synchronous signal generator. The synchronous signal is digitally processed by a digital signal processor. Thus, each parameter related to the number of passing cells is obtained by converting the analysis based on the time axis to the area analysis based on the frequency axis.
Abstract:
The present invention relates to a transmission line test method in the broadband ISDN for assembling an ATM formatted cell into a frame and sending it in the synchronous optical network (SONET) formatted transmission line as a protocol of an optical fiber communication network. First, test data are inserted into an ATM cell according to a command of the central controlling unit in an ATM switching unit. Then, the test cell is sent through an ATM switch in the ATM switching unit after the insertion of the test data; the test data are extracted from the test cell turned around by an ATM layer provided between the ATM switch and the SONET-formatted transmission line or by a subscriber terminal adapter, or from the test frame (including the test cell) turned around by a terminator in the SONET-formatted transmission line or by a network terminator at a subscriber terminal in the transmission line; and finally a transmission test is conducted by checking the data in the line up to each turnaround point.
Abstract:
An ATM exchange which is comprised of a multistage cascade connection of ATM switches of self-routing module structures which are provided with a plurality of outgoing lines and incoming lines, wherein it provides at the output side and the input side of the ATM switches output side conversion interfaces and input side conversion interfaces both for connection of adjoining ATM switches and uses optical cables to connect the output side interfaces and input side interfaces facing thereto. By this, it is possible to maintain the correct exchange operation even if the length of the transfer lines (outgoing lines and incoming lines) laid between ATM switches becomes greater along with extension of the ATM switches in the exchange.
Abstract:
An ATM (asynchronous transfer mode) exchange has a buffer for system #0 and a buffer for system #1 providing P-MEM's for storing data including an A bit and for a VCI/VPI currently in use is set to "1'. Upon detecting a switchover between the systems, every B bit is reset to "0". When the exchange while changing from a master to a slave receives a cell having a slave indication and while changing from a slave to a master it receives a cell having a master indication, respective systems rewrite B bits for VCI/VPI's of respective cells to "1". In the meantime, each of the P-MEM's calculates exclusive "OR" operations between the A bit and the B bit for every VCI/VPI, and further obtains a disjunction among all the exclusive "OR" operations thus obtained. Then, when both P-MEM's obtain "0" for their respective disjunctions, cells are read out from one of the buffers in the system changing from a slave to a master. This enables the ATM exchange having a switch duplexed by mutually asynchronous active and backup systems to switchover the systems without causing a cell to be duplicated or lost.
Abstract:
A main processor assigns originated-call processings to each of a plurality of call processors in the sequence of call originations according to the first principle of this invention. A switching state controller collects usage information about a plurality of buffers composing the switching network in the ATM exchanger. The call processors to which call processings are assigned perform the call processings based on the content of switching state controller a main processor assigns a call processing for an originated call to one of a plurality of call processors by referring to the call processing assignment table memory with the virtual channel identifier corresponding to an originated call according to the second principle of this invention thus, call processing loads are distributed among call processors.