International Business Machines Corporation

Edward Hau-chun Ku

Douglas Ray Henderson

Loren Blair Reiss

Joseph M Rash

Brian Mitchell Bass

Thomas Eric Ryle

Dennis Albert Doidge

Jim Philip Ervin

Scott J Lemke

Pramod Narottambhai Patel

Jeffrey Wayne Kidd

Karen Park Heron

Simin Hosne Sanaye

Charles Steven Lingafelt

Michael Steven Siegel

Paul S Chang

Norman Clark Strole

Joseph Kinman Lee

Kenneth Harvey Potter, Jr

Richard Colbert Matlack, Jr

Jack S Chorpenning

Sidney Brower Schrum, Jr

Joseph W Coates

Simin H Sanaye

Bou-Chung Lin

Jose Geraldo De Marco

Luis Filipe De Sousa Silva

Jean Huey Wingler

James Philip Ervin

A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layerprotocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

Method and apparatus for hardware forwarding of LAN frames over ATM networks

A multiported LAN switch comprised of legacy local area network ports and ATM ports. Each ATM port comprising a hardware forwarding engine for bridging LAN frames from the LAN ports to the ATM port. The hardware forwarding engine converts layer 2 protocols between the dissimilar ports expediently, without requiring intervention by a microprocessor. A substantial performance gain is attained compared to microprocessor controlled format converters. Both LAN emulation and virtual LANs are supported.

A method and system are provided for increasing processing efficiency associated with data frames transiting a network node having multiple ports. The method and system accomplish their objects via the following. A data frame having a header and data is received. An associated pointer for at least one portion of the received data frame is provided. The associated pointer is provided by segmenting each received data frame into parts, and associating with each segmented part a pointer. Thereafter, a portion of the received data frame is modified independent of other portions of the received data frame via utilization of given one or more of the associated pointers. Additionally, one or more copies of a portion (which can include the whole) of the received data frame is constructed by recalling each segmented part associated with one or more selected ones of the associated pointers. Furthermore, a determination is made as to whether the received header indicates unicast or multicast. In response to this determination, a number of data frames are constructed commensurate with protocols and destination addresses of one or more network nodes to which the constructed number of data frames is to be transmitted. The constructed data frames are transmitted from the node.

Multicast frame support in hardware routing assist

A system for coupling a local area network to a wide area network utilizes a PCI (Peripheral Component Interface) bus to couple a PCI interface to a PCI network interface card, which is coupled to the wide area network. The wide area network could be an asynchronous transfer mode network or a high bandwidth ethernet. If the PCI network interface card operates as a PCI master, then the PCI interface will operate as a PCI slave. If the PCI network interface card operates as a PCI slave, then the PCI interface of the invention will operate as a PCI master.

Protocol for using a PCI interface for connecting networks

A method and system are provided for enabling simultaneous cut-through and store-and-forward transmission of frames in high speed network devices. A Buffer Parameter Vector chains multiple frame buffers together. Frame Parameter Vectors created for each unique version of a frame are used to manage frames as they flow through the network device. Cut-through/store-and-forward decision logic determines whether frames can be transmitted by cut-through or store-and-forward. Multiple unique frames or copies of a frame that are to be transmitted store-and-forward have their Frame Parameter Vectors chained together by pointers. The cut-through/store-and-forward decision logic steps through the chain of Frame Parameter Vectors resulting in the frames associated with each Frame Parameter Vector being transmitted.

Simultaneous cut through and store-and-forward frame support in a

A device for interconnecting Local Area Networks (LANs) includes ports for attaching LAN segments and port modules for connecting the ports to a switch fabric. Each of the port modules include a mechanism which searches the Routing Information (RI) field of a Received frame to detect at least two Triplets (a minimum configuration for a LAN segment) indicating a Source path from an originator user and a Destination path to a destination user. The Triplet (single or in combination) is used to access a database (tables) which identifies the Port of Exit (POE) through which the frame is to be routed.

Process definition for source route switching

Method and apparatus for hardware forwarding of LAN frames over ATM

A method and system are provided for traffic shaping and bandwidth scaling in a high speed internetworking device. A slot time wheel mechanism is provided for traffic rate control and a credit/debit mechanism is provided for traffic shaping and scaling. The high speed traffic scaler and shaper incorporates a programmable slot time wheel, a traffic scaler state machine, a traffic shaper parameter table and a traffic scaler processor. The traffic scaler processor incorporates a traffic queue allocation manager, a queue priority arbiter, a port enable selector, a port priority arbiter and a DMA channel arbiter. The traffic queue allocation manager and the queue priority, port priority and DMA channel arbiters are each controlled by a corresponding state machine. The parameters in the traffic shaper parameter table are dynamically updated for each logical queue and are used to enable the credit/debit mechanism.

High speed internetworking traffic scaler and shaper

A memory interface for multi-port access to a memory unit, such as a static random-access memory (SRAM) device. The memory interface, which is generally adapted for a local area network (LAN) forwarding engine, provides single port read/write access to SRAM device, and arbitrates requests from the access interfaces to allocate bandwidth of the SRAM device among the requests. One embodiment allocates at least 50% of the bandwidth to a peripheral component interface (PCI) bus target interface and a PCI bus master interface, collectively. The arbitration logic may include a plurality of bandwidth control registers associated with respective access interfaces used to determine a permitted amount of bandwidth that an access interface is to have, wherein a request from an access interface is masked based on a value in its associated bandwidth control register. Arbitration can further allocate bandwidth using time division multiplexing.

Multi-port SRAM access control using time division multiplexed

A method of parsing frame headers for routing data frames within a computer network is disclosed. In accordance with the method and system of the present invention, a data frame is first received from a computer network. A frame header of the data frame is then parsed into multiple test units of identical lengths. A test vector is subsequently assigned to each of the test units, wherein each test vector includes a reference pattern field and an action code pointer field. A number of test blocks are constructed by inserting each of the test vectors into a corresponding slot of various test blocks. Finally, a search tree is constructed by utilizing these various test blocks, and each test block is associated with each other test block via the test vectors contained within.

Method and system of parsing frame headers for routing data frames

A sequence in which two or more of the data units enter the network node, via a specific one of the multiple ports, is recorded. And, the two or more of the data units are transmitted from the network node according to the recorded sequence. The method and system achieve the recording of sequence via the following. In response to an insertion of one of the two or more data units into a specific one of the multiple processor subsystems, the specific one of the multiple processor subsystems is associated with a specific one of the multiple ports by which the one of the two or more data units entered the network node, and any other of the multiple processor subsystems that are currently processing on any other of the two or more data units that entered the network node through the specific one of the multiple ports is noted. Thereafter, any request to transmit by the specific one of the multiple processors is honored if it is determined that the data unit with the requesting processor is next according to the recorded sequence. The data unit is determined to be next in sequence if all of the multiple processors, that were processing on other data units which entered through the specific one of the multiple ports, have completed processing.

Maintaining frame sequence in a multiprocessor network device

A method for improving the performance of an existing busoriented computer system with minimum or no design change to the existing hardware, bus protocol, or bus operation is disclosed. Specifically, the present invention improves the effective bandwidth of an existing bus architecture by creating multiple physical instantiations of the existing bus and directing traffic onto these different buses based on the type of bus operation being performed. This results in multiple components having the capability to simultaneously perform bus operations, therefore improving the effective bandwidth of the system. This invention also allows the components which are current being utilized in the existing bus architecture to be re-utilized with minimum additional external logic.

Method for modifying an existing computer bus to enhance system

A system and method for efficiently routing data within a network, such as a local area network. A search tree is utilized within the bridge/router in order to store addresses. The search tree is utilized by the router for more efficiently and more quickly determining where one or more received frames of data are to be transmitted within the network. Maintenance of the search trees is also provided so that new addresses may be added to the search trees and addresses may be deleted from the search trees. The search trees are developed by partitioning the addresses into bit groups.

System and method utilizing multiple search trees to route data within a

A data processing system includes a server which has a task scheduler for receiving task requests for access, and granting access to system resources based upon a multidimensional scheduling technique wherein groups of tasks are assigned a priority level within a priority scheme, and within each group round robin scheduling assures each task will have access to system resources in turn and a dynamically programmable technique for responding to requests from time-dependent isochronous requests for system resources.

Growing community of inventors

Cary, NC, United States of America

Edward Hau-chun Ku