Hitachi, Ltd.

Fujitsu Corporation

Tadahiro Takase

Yoshifumi Takamoto

Satoshi Kuroyanagi

Hiroki Kanai

Satoshi Kakuma

Ryuichi Takechi

Masami Murayama

Takeshi Kawasaki

Yoshimasa Masuoka

Tetsuo Tachibana

Katsuyoshi Kitai

Hiroshi Tomonaga

Jyoei Kamoi

Kazuo Hajikano

Toshio Shimoe

Teruaki Hagihara

A communication controller at the sending computer divides data transferred from a host into sub-ACK unit packets, and transfers them sequentially to a destination without waiting for the sub-ACK's being subsequently provided by the destination. A communication controller at the receiving computer issues a sub-ACK to the sending computer for each of the sub-ACK unit packet, if the sub-ACK packet has been normally received and otherwise issues retransmission request for the sub-ACK unit packets and merges data included in the sub-ACK unit packets into the initial data, after they are normally received.

Method for transmitting data via a network in a form of divided sub-packets

Method and apparatus for transmitting data in a network wherein acknowledgment signals are transmitted to acknowledge receipt of data

The object of the present invention is accomodating local connectionless information (data that is immediately transferred without establishing a path to a receive side), such as LAN data in a local area network, by an asynchronous transfer mode (ATM) network using a connection-oriented communication system (which makes data transfers after verifying that a path to the receive side has been established), thereby performing efficient, fast routing of connectionless information. A connectionless communication system of the present invention is equipped with connectionless information cell assembly/deassembly means for bi-directional conversion between variable-length connectionless information and fixed-length connectionless cells, routing control means for analyzing a destination address of information in connectionless cells and controlling the routing of the connectionless cells; and an ATM network for connecting the connectionless information cell assembly/deassembly means and the routing control means by a permanent virtual channel serving as a fixed path and connecting the routing control means together by a virtual channel serving as a semi-fixed path, whereby connectionless information is segmented into connectionless cells and the connectionless information is exchanged within the ATM network in connectionless cell units.

Connectionless communication system

A communication controller at the sending computer divides data transferred from a host into sub-ACK unit packets and transfers them sequentially to a destination without waiting for the sub-ACK's being subsequently provided by the destination. A communication controller at the receiving computer issues a sub-ACK to the sending computer for each of the sub-ACK unit packet, if the sub-ACK packet has been normally received and otherwise issues retransmission request for the sub-ACK unit packets and merges data included in the sub-ACK unit packets into the initial data, after they are normally received.

Method of transferring packet data in a network by transmitting divided

A communication system for use with a network for transmitting fixed-length cells from a transmitting terminal via a virtual connection in the network to a receiving terminal. The communication system includes a converting device, connected to the transmitting terminal or the receiving terminal, for performing a bi-directional conversion between a variable-length packet and the fixed-length cells, the transmitting terminal or the receiving terminal outputting the variable-length packet, a buffer capacity monitoring device in the receiving terminal for monitoring a capacity of a buffer in the receiving terminal receiving the fixed-length cells and for outputting an alarm signal at the time of detecting a congestion state of the capacity of the buffer, a congestion state alerting device in the receiving terminal responsive to the alarm signal from the buffer capacity monitoring device for outputting an alert signal to the transmitting terminal, and a traffic transmission control device in the transmitting terminal responsive to the alert signal from the congestion state alerting device in the receiving terminal for controlling a transmission of the fixed-length cells to the receiving terminal.

A communication system for transmitting a fixed-length cell converted from a variable-length information including data and a destination of the data. The system includes a cell assembly/disassembly device for performing bi-directional conversion between the variable-length information and the fixed-length cell, a routing control device for receiving the fixed-length cell converted from the variable-length information by the cell assembly/disassembly device, for analyzing the destination of the data and for controlling a routing of the fixed-length cell based on the analyzed destination, and having an error detecting device for detecting an error of the variable-length information in the fixed-length cell, and a network for connecting the cell assembly/disassembly device and the routing control device by a fixed capacity path and for connecting the routing control device to another routing control device by the fixed capacity path or a variable capacity path.

Growing community of inventors

Oita, Japan

Tadahiro Takase