Fujitsu Corporation

Yoshihiro Uchida

Yasuhiro Aso

Satoshi Kakuma

Masami Murayama

Shiro Uriu

Naoyuki Izawa

Shuji Yoshimura

Yoshihiro Watanabe

Mikio Nakayama

Yoshiharu Kato

Takashi Hatano

Kenichi Okabe

Jun Itoh

Jin Abe

Noriko Samejima

Hiroshi Nishida

Eiji Ishioka

Shigeru Sekine

Satoshi Esaka

Miyuki Kawataka

Yoshiyuki Karakawa

Fumio Hirase

Atsuhisa Takahashi

Yasuhiro Nishikawa

Shinichi Araya

Nobuyuki Tsutsui

Atsushi Kagawa

Shouji Kohira

Atsuko Suzuki

Yoshihisa Tsuruta

Hiromi Yamanaka

Akira Shimamura

Jyoei Kamoi

Naoki Aihara

Makoto Adachi

Hiroshi Miyake

Yuji Tazaki

Kazuhito Yasue

Yasusi Kobayasi

Taisuke Sasaki

Kazuhiko Kumagai

Yoshiyuki Tokoi

Hajime Yamashita

Hirotoshi Mori

Yasusi Kobayashi

Yumiko Kato

Shurji Yoshimura

A communication method using link aggregation, the method includes receiving a transfer frame; calculating, by a first communication device, an identification number of an output port for the transfer frame among a plurality of ports using a hash function, by using a combination of a source address of the transfer frame, a destination address of the transfer frame, and a cyclic number that is generated for every combination of the source address and the destination address and represents an order of the transfer frame as a hash key; and transmitting the transfer frame from the output port.

Communication method, communication device, and communication system

A switch station including an ATM switch; a memory storing control data for operations of the switch station; an intra-station device, accommodating a subscriber line, performing communication operation on subscriber ATM cell; a control processor generating control information in link access protocol (LAP) format; and an interface unit converting LAP control information into ATM cell to the intra-station device through the ATM switch, wherein the control information is communicated according to LAP, the intra-station device receives the control information and transmits a direct memory access request to obtain control data stored in the memory, the interface unit obtains and converts the data format of the control data into ATM cell to transmit to the intra-station device through the switch, and the intra-station device performs the communication operation on the subscriber ATM cell based on the control data received through the switch.

Intra-station control system for connectionless communications system

In a connection oriented mode communication system, a communication connection is established as an alternative connection substitutive for a currently working communication connection so that the alternative connection connects the couple of node apparatus connected through the currently working communication connection to each other by way of a route physically different from that of the currently working communication connection. According to the above arrangement, it becomes possible to carry out maintenance, moving of facility or the like of a network including the currently working connection without interrupting the service which is provided through the currently working connection.

Apparatus for user connection setting in a connection oriented mode communication system

A system for controlling a bandwidth when receiving and reassembling a consecutive data stream transferred while segmented by AAL1 format cells which enables correct determination of non-P and P formats and reassembly of cells even when error arises in multiple bits including the CSI bit of an AAL1 cell or when adding dummy cells and thereby enabling prevention of a gap in data in a frame, comprising, in a data reassembly unit which reassembles received cells, an 8-cell buffer for storing 8 cells of a cycle of a sequence count (SC) of 0 to 7 and sending the cells out to a later stage after a check unit of a sequence number (SN) field confirms normalcy of the cells and a control unit for control so that the number of P format cells stored in the 8-cell buffer becomes 1 cell when 8 cells are stored in the 8-cell buffer.

System for controlling AAL1 cell bandwidth

A memory vacancy management apparatus for managing vacant addresses of a memory which is capable of storing various information, includes a vacant address management table having a number of addresses identical to a number of addresses of the memory, and storing vacancy information indicating whether or not the addresses of the memory are vacant. The vacancy information with respect to an address of the memory having an arbitrary address value is stored at an address of the vacant address management table having the same arbitrary address value.

Memory vacancy management apparatus and line interface unit

Disclosed is an interface apparatus in a communication network for converting a frame, which has been received from a digital transmission line and has overhead and a payload, to ATM cells, assembling a frame using ATM cells that have been received from an ATM network, and sending the assembled frame to a digital transmission line. The apparatus includes cell conversion zone specifying means for defining, as a cell conversion zone, the smallest possible portion of a frame that contains the overhead data and payload, and generating a signal that specifies the cell conversion zone; pointer creation means for creating a pointer which specifies a predetermined position of the cell conversion zone as a reference position; and cell conversion means for converting data in the cell conversion zone into cells based upon the signal that specifies the cell conversion zone, and for inserting this pointer, which indicates the reference position of the cell conversion zone, in a prescribed cell. On the ATM-cell receiving side, the apparatus detects pointers, assembles ATM cells into a frame based upon the pointers and transmits the frame.

Interface apparatus

An ATM switch includes routing modules in each of which modules ATM cells can be switched at crosspoints of inputs and outputs, input units which are respectively provided to input highways and add tags to the ATM cells transferred over the input highways, the tags being used to switch the ATM cells in the routing modules, the ATM cells with the tags added being supplied to the routing modules, and output units which are respectively provided to output highways and multiply the ATM cells supplied from the routing modules to output the ATM cells to the output highways.

ATM switch

The quality and performance of the connectionless communications system are improved. When a BOM is received, the destination address DA of the L3-PDU stored in the payload of the BOM is retrieved, and the tag information is obtained from the DA (S,). The output message identifier MID is reserved (S,), and the tag information and output MID are assigned to the BOM (S,). Then, the tag information and output MID are written to the table. When a COM is received, the tag information and output MID are retrieved using the MID of the COM as a key, and the information is provided for the COM (S,and S,). When an EOM is received, the tag information and output MID are retrieved using the MID of the EOM as a key, and the information is provided for the EOM (S,and S,). Then, the output MID is released (S,).

Connectionless communications system, its test method, and intra-station control system

An ATM switch accommodates a plurality of input lines. Conversion controlling units are disposed corresponding to the input lines. Each of the conversion controlling units analyzes a header of a cell received through the relevant input line and accesses a common conversion table corresponding to routing information included in the header. The common conversion table is disposed in common with the input lines. The common conversion table collates routing information of cells received through the input lines with output routing information and stores the collated data. Each of the conversion controlling units extracts output routing information from the common conversion table corresponding to the routing information of a cell received through the relevant input line, adds output routing information to the header of the cell, and sends the resultant cell to the ATM switch.

Header converting method

A sending trunk on the input side of an ATM switch is equipped with a test cell generating section, and a receiving trunk on the output side of the ATM switch is equipped with a test cell detecting section. The test cell generating section includes a unit for setting a test cell identifier in the header of a test cell and a unit for generating pieces of data with regularity in the information field of the test cell. The test cell detecting section includes a unit for detecting the test cell identifier from the header of a cell received and a unit for detecting regularity from data in the information field of the cell received. When a test cell is transmitted, the test cell detecting section evaluates the result of a test on the basis of the result of detection of the test cell identifier from the header of the test cell and the result of detection of the regularity from data in the information field of the test cell.

Path test system for ATM switch

A SMDS (Switched Multi-megabit Digital Service) switching apparatus provides connectionless-mode high-speed digital data switching services suitable for use in connection between telecommunication terminals, e.g. LANs (Local Area Networks) via a network. The SMDS switching apparatus is formed of plural subscriber's circuits, each of the plural subscriber's circuits accommodating at least one subscriber's terminal; an automatic routing selection switch connected to the plural subscriber's circuits, the automatic routing selection switch receiving a fixed length cell formed of a logic channel information portion and a data portion and selecting automatically an output route for the fixed-length cell, based on information in the logic channel information portion; and an analyzing unit receiving a fixed-length cell sent from the automatic routing selection switch and then analyzing sender information and receiver information each regarding the fixed-length cell. The object is to provide a SMDS switching apparatus wherein an arrival-site processing unit executes the routing procedure in an originating-site processing unit to suppress an increase in the capacity of the routing table.

Switched multi-megabit digital service switching apparatus

An ATM (asynchronous transfer mode) cell broadcasting system for use in ATM switches comprises switch matrices for exchanging ATM cells inputted from a plurality of input highways and outputting them to a plurality of output highways. The ATM cell broadcasting system further includes tag information adders, provided at respective input terminals of the switch matrices, for adding tag information according to respective identifiers assigned to the ATM cells. Alternatively, ATM-cell-switching identifier determinant memories may be provided for respective switch elements in the switch matrices, for storing determinant data enabling the switch elements to determine, from the identifiers of the ATM cells, which ones of the ATM cells are to switch and output to their respective output highways.

ATM cell broadcasting system

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.

Information processing system for obtaining status data of a simplex

An elastic store memory circuit includes first and second elastic store memories. Each of the first and second elastic store memories generates a phase comparison signal when a phase difference between a write timing and a read timing is within a predetermined phase range. The elastic store memory circuit also includes a selector which selects either the input data read out from the first elastic store memory or the input data read out from the second elastic store memory, and a slip signal generator for generating a slip signal on the basis of a write reset timing at which the first and second elastic store memories are reset, a read reset timing at which the first and second elastic store memories are reset, and the phase comparison signal. The slip signal indicates which one of the write reset timing and the read reset timing precedes the other one.

Elastic store memory circuit

Growing community of inventors

Kawasaki, Japan

Yoshihiro Uchida