Hitachi, Ltd.

Kenichi Ohtsuki

Yoshito Sakurai

Shinobu Gohara

Hiroshi Kuwahara

Takao Kato

Eiichi Amada

Makoto Mori

Akira Horiki

Taihei Suzuki

Shirou Tanabe

Manabu Okamoto

Takahiko Kozaki

Noboru Endo

Yutaka Torii

A packet switching system including at least one switching node or local unit each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch based on a logic channel on a packet circuit, a self-routing switch for performing switching based on the output port information, and a control unit for terminating a control packet and performing the call processing function. A switching node or tandem unit is provided including at least one self-routing switch for interconnecting the local units. A device is provided for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating-side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device.

Packet switching system having self-routing switches

An ATM switching system comprises a switch unit including a plurality of input ports and a plurality of output ports having the same cell transmission rate, and a multiplexer for multiplexing cell trains outputted from at least two output ports into a single cell train and outputting the cell train to a high-speed output line (and/or a demultiplexer for demultiplexing a cell train from an output port into a plurality of cell trains and outputting the cell trains to a plurality of low-speed output lines). The switch unit includes a buffer memory for temporarily storing cells inputted from the input ports while forming a queue chain for each output line to which each cell is to be outputted, a demultiplexer for distributing the cells read from the buffer memory among the output ports in circulation, and a buffer memory control circuit for controlling the write and read operation of cells with the shared buffer memory. The buffer memory control circuit has a control table device for outputting an identifier of an output line to which the cells read from the shared buffer memory are to be outputted, and cells are read from the chain designated by the output line identifier outputted from the control table device.

ATM cell switching system

A switching system for integratedly switching voice, data, image information and the like. The switching system comprises a plurality of front-end modules each adapted to perform a switching processing in association with a subscriber line or a trunk line, and a single or a plurality of central modules for interconnecting the plurality of front-end modules in star-type fashion and switching information prevailing between the front-end modules, in unit of block accommodating the information and a header added thereto to contain connection control information and in accordance with the contents of the header. The front-end modules are connected to the central module via inter-module highways each having frames occurring at a predetrmined period and time slots contained in each frame to carry blocks.

Distributed type switching system

In a packet switching system-made up of a single or a plurality of switching nodes or local units each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch on the basis of a logic channel on a packet circuit, a self-routing switch for performing switching on the basis of the output port information, and a control unit for terminating a control packet and performing the call processing function, and a switching node or tandem unit including a single or a plurality of self-routing switches for interconnecting the local units, there are provided a device for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating, side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device, operable in the originating-side local unit for information transfer, for inserting output port information of the self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit, whereby in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating side local unit arrives at the tandem unit, the packet is transferred to the destination side local unit without undergoing termination of packet and concomitant call processing control.

Packet switching system having-having self-routing switches

An ATM switching system including a switch unit having a plurality of input ports and output ports, and a multiplexer for multiplexing cell trains from at least two output ports into a single cell train and outputting the cell train to and output port. A demultiplexer can be provided in place of the multiplexer. The switch unit includes a buffer memory for storing cells from the input ports while forming a queue chain for each output port, a demultiplexer for distributing the cells from the buffer memory to output ports, and a buffer memory control circuit for controlling write and read operations of the buffer memory. The buffer memory control circuit has a control table for outputting an identifier of an output port the cells read from the buffer memory are to be output. Cells are read from the chain designated by the identifier.

A switching system for integratedly switching voice, data, image information and the like. The switching system comprises a plurality of front-end modules each adapted to perform a switching processing in association with a subscriber line or a trunk line, and a single or a plurality of central modules for interconnecting the plurality of front-end modules in star-type fashion and switching information prevailing between the front-end modules, in unit of block accommodating the information and a header added thereto to contain connection control information and in accordance with the contents of the header. The front-end modules are connected to the central module via inter-module highways each having frames occurring at a predetermined period and time slots contained in each frame to carry blocks.

In a packet switching system made up of a single or a plurality of switching nodes or local units each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch on the basis of a logic channel on a packet circuit, a self-routing switch for performing switching on the basis of the output port information, land a control unit for terminating a control packet and performing the call processing function, and a switching node or tandem unit including a single or a plurality of self-routing switches for interconnecting the local units, there are provided a device for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating-side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device, operable in the originating side local unit for information transfer, for inserting output port information of the self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit, whereby in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating-side local unit arrives at the tandem unit, the packet is transferred to the destination-side local unit without undergoing termination of packet and concomitant call processing control.

In a packet switching system made up of a single or a plurality of switching nodes or local units each including a label conversion unit for accommodating a plurality of packet circuits and performing conversion into output port information of a switch on the basis of a logic channel on a packet circuit, a self-routing switch for performing switching on the basis of the output port information, and a control unit for terminating a control packet and performing the call processing function, and a switching node or tandem unit including a single or a plurality of self-routing switches for interconnecting the local units, there are provided a device for setting, between the tandem unit and a destination-side local unit, the same logic channel as that between an originating, side local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than this local unit and a device, operable in the originating-side local unit for information transfer, for inserting output port information of the self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit, whereby in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating-side local unit arrives at the tandem unit, the packet is transferred to the destination-side local unit without undergoing termination of packet and concomitant call processing control.

Time-division channel arrangement

A packet switching system which includes a device for setting, between a tandem unit and a destination local unit, the same logic channel as that between an originating local unit operative for information transfer and the tandem unit in respect of a call destined for a local unit other than the originating local unit and a device, operable in the originating-side local unit for information transfer, for inserting output port information of a self-routing switch inside the tandem unit into a packet destined for the local unit other than this local unit; in the tandem unit, setting of logic channel conversion information is not required to be done and even when any control signal packet from the originating local unit arrives at the tandem unit, the packet is transferred to the destination local unit without undergoing termination of packet and concomitant call processing control.

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Kanagawa-ken, Japan

Kenichi Ohtsuki