Fujitsu Corporation

Fujitsu Network Communications, Inc.

Robert B McClure

Stephen A Caldara

Thomas A Manning

Stephen A Hauser

Matthias L Colsman

A communication device (10) includes a number of input/output modules (12) coupled to a switch control module (14) using an interconnect (40) and to a redundant switch control module (16) using a redundant interconnect (42). Each interconnect (40) and redundant interconnect (42) includes a control interconnect (44) and a data interconnect (46). The control interconnect (44) establishes control information for transferring a cell in the communication device (10) and the data interconnect (46) performs the cell transfer.

Serial control and data interconnects for coupling an I/O module with a

A method and apparatus for controlling network service parameters in a cell based communications network. A plurality of input signals are received on input ports of a communications device and a plurality of output signals are sourced from output ports, wherein at least one input signal and at least one output signal comprise, respectively, at least one virtual connection. The communications device is part of a cell based communications network and each virtual connection comprises a series of data cells comprising a header portion and a data portion. A first virtual connection is assigned to an input queue of an input port and an output queue of an output port. Each queue is associated with a first buffer space dedicated to the respective queue. Each queue is also associated with a second buffer space that is shared between the respective queue and other queues. The second buffer space is utilized after the first buffer space becomes full. Data associated with the first virtual connection is queued in the input and output queues. The communications device also includes a switching fabric intermediate the input ports and the output ports. Bandwidth into the switching fabric is allocated by the input port, and bandwidth out of the device is allocated by the output port.

Method and system for controlling network service parameters in a cell

An asynchronous transfer mode (ATM) based service consolidation switch (10) includes an input/output module (22) having a to-switch port (TSPP) processor (90) and a from-switch port processor (FSPP) (92). The TSPP (90) and the FSPP (92) communicate with a bandwidth arbiter (114), multipoint topology controllers (116), and a data crossbar (117) on a switch control module (32). The TSPP (90) receives traffic over links for conversion into an internal cell format. Internal cells are buffered until allowed to transfer to an appropriate FSPP (92). Multipoint topology controllers (116) performs translations for internal switch flow control through interactions between the TSPPs (90), FSPPs (92), and the bandwidth arbiter (114). The bandwidth arbiter (114) performs appropriate bandwidth arbitration to allow internal cells to flow from TSPPs (90) to FSPPs (92) over the data crossbar (117).

Asynchronous transfer mode based service consolidation switch

The invention comprises a method and apparatus for reducing information loss in a communications network. In accordance with the method of the invention, a plurality of virtual connections are sent over a first link from a first node in the communications network to a second node. The first and second nodes comprise a plurality of input queues coupled to a switching network which is in turn coupled to a plurality of output queues. Each virtual connection is associated with a first output queue in the first node and a second input queue and a second output queue in the second node. A connection feedback signal is provided from the second node to the first node comprising data reflecting the status of the second input queue associated with a virtual connection. The flow of information between the first node and the second node is controlled for each virtual connection in response to the connection feedback signal associated with that virtual connection. In addition, a switch feedback signal is provided from the second output queue to the second input queue for each virtual connection. The switch feedback signal for a particular virtual connection comprises data reflecting the status of the second output queue associated with the virtual connection and is used to control the flow of information between the second input queue and the second output queue for each virtual connection in response to the switch feedback signal associated with that virtual connection.

Method and apparatus for reducing information loss in a communications

The invention comprises a method and apparatus for emulating a circuit connection in a cell based communications network. A virtual connection is sent from a source connected to the network to a node in the network wherein the virtual connection comprises a series of data cells comprising a header portion and a data portion. The virtual connection is transported across at least one communications link connecting the first node to a second node in the network. A first queue is dedicated to the virtual connection at each node in the network through which the signal passes. The queue comprises a first amount of buffer space, is dedicated for the duration of the circuit connection and, dedicated only to that virtual connection. A first amount of link bandwidth is allocated to the virtual connection on each communications link across which the virtual connection passes. The amount of link bandwidth is allocated for the duration of the circuit connection and is allocated only to that particular virtual connection. The virtual connection is received at a destination connected to the communications network at a node of the communications network.

Method and apparatus for emulating a circuit connection in a cell based

An ATM network switch and method of utilization for adaptively providing integrated services therein is disclosed. In providing such integrated services, if the allocated bandwidth for one connection has been consumed, or if the connection is not entitled to allocated bandwidth, the connection can optionally use dynamic bandwidth arbitration, or a combination of both allocated and dynamic. The switch includes an input port processor, a bandwidth arbiter, and an output port processor. Cells are transmitted from the input to the output, under the control of respective port processors and the bandwidth arbiter. Flow control is implemented on a per-connection basis. Individual queues are then assigned to traffic type groups in order to provide traffic type flow control. Based upon prioritization information associated with the cell at the input, cells are prioritized and transmitted from the output, with each cell maintained in the same order, relative to other cells on a connection, in which it was received.

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Hollis, MA, United States of America

Robert B McClure