Advanced Micro Devices Corporation

Advanced Medical Devices, Inc.

Gopal S Krishna

Somnath Viswanath

Mohan V Kalkunte

Bahadir Erimli

Peter Ka-Fai Chow

Mrudula Kanuri

Shashank C Merchant

Shr-Jie Tzeng

Robert Alan Williams

Chandan Egbert

Jim Mangin

Ching Yu

Alok Singh

Jayant Kadambi

Peter Chow

Jenny Liu Fischer

Xiaohua Zhuang

A multiport switch distributes conversations over links in a trunk. The multiport switch includes receiver ports, transmitter ports, and a routing engine. The receiver ports receive data frames belonging to one or more of the conversations. The transmitter ports transmit the received data frames over the links in the trunk. The routing engine distributes the conversations over the links in the trunk by identifying at least one field in each of the received data frames, assigning each of the received data frames to a corresponding one of the one or more conversations based on the identified fields, and selecting the links in the trunk over which to transmit the received data frames based on the conversation assignments.

Trunking distribution systems and methods

A network switch includes network switch ports, each including a port filter configured for detecting user-selected attributes from a received layer 2 type data frame. Each port filter, upon detecting a user-selected attribute in a received layer 2 type data frame, sends a signal to a switching module indicating the determined presence of the user-selected attribute, enabling the switching module to generate a switching decision based on the corresponding user-selected attribute and based on a corresponding user-defined switching policy. The switching policy may specify a priority class, or a guaranteed quality of service (e.g., a guaranteed bandwidth), ensuring that the received layer 2 type data frame receives the appropriate switching support. The user-selected attributes for the port filter and the user-defined switching policy for the switching module are programmed by a host processor. Hence, the integrated network switch is able to perform advanced switching operations for layer 2 type data packets to ensure quality of service requirements, independent of priority information specified in the layer 2 type data packets, based on the user-selected attributes in the layer 2 type data packets and the user-defined switching policies established for the switching module.

Arrangement in a network switch for prioritizing data frames based on user-defined frame attributes

A communication processor comprises a data link layer parser circuit () and a plurality of network layer parser circuits (). The data link layer parser circuit () receives a data link layer frame, and removes a data link layer header therefrom to provide a network layer frame as an output. Each network layer parser circuit corresponds to a different network layer protocol, and is selectively activated to receive the network layer frame and to process a network layer header therefrom to provide a transport layer frame as an output. The data link layer parser circuit () further examines a portion of the network layer frame to determine which of the plurality of network protocols is used. The data link layer parser circuit () activates a corresponding one of the plurality of network layer parser circuits () in response, while keeping another one of the plurality of network layer parser circuits () inactive.

Data communication system with hardware protocol parser and method therefor

A multiport switching device includes a configuration table that stores associations between addresses of subnets directly connected to the switching device and the port number of the multiport switching device that leads to the subnet. A host processor connected to the multiport switching device updates and maintains the configuration table. A remote processor communicates with the switching device through the host processor. To facilitate the communication of the remote processor with the multiport switch, the host processor executes a TCP/IP stack and the multiport switch is assigned a unique IP address.

Remote configuration of a subnet configuration table in a network device

A network switch, configured for performing layerand layerswitching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a packet classifier module configured for evaluating an incoming data packet on an instantaneous basis. The packet classifier module performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. Hence, the packet classifier module is able to monitor data flows between two network nodes interacting according to a prescribed network application. The packet classifier module determines the application state for a prescribed network application from a received layerdata packet, enabling switching logic within the network switch to utilize application-specific aging intervals for respective network applications such as HTTP, SNMP, ftp, Telnet, etc. in order to delete aged address entries from a network switch address table based on the supported network application. Determination of the application state from the received layerdata packet also enables the network switch to detect the end of a data flow for deletion of the corresponding address entry from the network switch address table.

Selective address table aging in a network switch based on application state determined from a received data packet

A network switch includes network switch ports, each including a port filter configured for detecting user-selected attributes from a received layerframe. Each port filter, upon detecting a user-selected attribute in a received layerframe, sends a signal to a switching module indicating the determined presence of the user-selected attribute, for example whether the data packet has a prescribed priority value. The network switch includes a flow control module that determines which of the network switch ports should output a flow control frame based on the determined depletion of network switch resources and based on the corresponding priority value of the network traffic on each network switch port. Hence, any network switch port that receives high priority traffic does not output a flow control frame to the corresponding network station, enabling that network station to continue transmission of the high priority traffic. In most cases, the congestion and depletion of network switch resources can be alleviated by sending flow control frames on only those network switch ports that receive lower priority traffic, enabling the network switch to reduce congestion without interfering with high priority traffic.

Flow control arrangement in a network switch based on priority traffic

A network switch, configured for performing layer 2 and layer 3 switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis, immediately upon receipt at the network switch port. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. The templates may be programmed by a user and stored in an internal min term memory. Moreover, the multiple simultaneous comparisons enable the network switch to perform layer 3 switching for 100 Mbps and gigabit networks without blocking in the network switch.

Apparatus and method for identifying data packet at wire rate on a network switch port

A network device that controls the communication of data frames between stations includes a memory that stores frame pointers that point to addresses in an external memory. The data frames are stored in the external memory while the network device generates frame forwarding information for the respective data frames. The network device divides the available frame pointers into a number of categories corresponding to priorities associated with the data frames. When a frame is received at the network device, frame processing logic determines the priority of the data frame and checks whether a frame pointer corresponding to that particular priority is available. If no frame pointer corresponding to that priority is available, the multiport switch drops the data frame.

Method and apparatus for performing priority-based admission control

A network switch, configured for performing layerand layerswitching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes network switch ports, each including a flow module configured for generating a packet signature based on layerinformation within a received data packet. The flow module generates first and second hash keys according to a prescribed hashing function upon obtaining first and second portions of layerinformation. The flow module combines the first and second hash keys to form the packet signature, and searches an on-chip signature table that indexes addresses of layerswitching entries by entry signatures, where the entry signatures are generated using the same prescribed hashing function on the first and second layerportions of the layerswitching entries.

Arrangement for searching packet policies using multi-key hash searches in a network switch

A network switch, configured for performing layerand layerswitching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes network switch ports, each including a packet classifier module configured for generating a packet signature based on information within a received data packet and hash action values specified within a user-programmable template. In particular, the network switch stores a plurality of user-programmable templates, each configured for identifying a corresponding class of data packet. Each user-programmable template includes hash action values specifying initiation and termination of a hash function based on a byte offset of a received data packet. The packet classifier module includes a hash generator configured for generating hash values for selected bytes of the received data packet, and a template translator configured for controlling the hash generator for hashing the selected bytes of the received data packet based on the hash action values specified by a corresponding user-programmable template. Hence, a unique hash signature can be generated by supplying a data frame having a prescribed data values at the selected bytes of the user-programmable template; the hash signature can then be stored for comparison with incoming data packets during network switching operations. Hence, data packets can be classified at the wire rate by performing a hash-based search of selected bytes of the received data packet.

Packet classification using hash key signatures generated from interrupted hash function

A multiport network device includes output ports, internal rules checking logic, a port filter, and input ports. The input ports receive data frames and transfer the data frames to the internal rules checking logic and the port filter. The internal rules checking logic determines the appropriate output ports for the frame. At potentially the same time, the port filter determines priority information for the frame. The port filter informs the internal rules checking logic when it has completed determining the priority information by transmitting an end-of-frame signal to the internal rules checking logic. In response, if the internal rules checking logic has completed determining the output ports for the frame, it assembles a frame descriptor corresponding to the frame and transmits the frame descriptor to the appropriate output port(s).

Parallel packet lookup in a packet-switched network

A network switching system having a plurality of multiport switch modules and respective connected buffer memory devices assigns in each of the buffer memory devices a memory segment for storage of frame data from a corresponding one of the switch modules. Each memory device is divided into memory segments, also referred to as memory regions, wherein each memory segment is configured for storing frame data from a corresponding one of the switch modules. Hence, each switch module is configured for writing frame data, for a data frame received on one of the corresponding switch ports, into the corresponding assigned memory segment of each of the buffer memory devices. Any one of the switch modules can access any location of the buffer memory devices, enabling any one switch module to retrieve frame data from the buffer memory devices that was stored by another one of the switch modules. In addition, the assignment of memory segments enables a switch module having accessed frame data from the buffer memory to determine the switch module that originally stored the frame data based on the location of the stored frame data within one of the memory segments, simplifying buffer memory resource management.

Segmention of buffer memories for shared frame data storage among multiple network switch modules

A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter within any one of the respective switch ports if backpressure is asserted by that port. The resetting of the retry counter within a port after assertion of backpressure affords the port a greater probability of winning collision mediation under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch.

Apparatus and method for resetting a retry counter in a network switch port in response to exerting backpressure

A centralized policy server sends policy messages, that describe network management policy, to network switches. Each policy message includes a packet attribute that enables a network switch to uniquely identify a received data packet, and either a priority level or network switch action that describes the switching operation to be performed by the network switch. The network switches are configured for implementing the network management policy by storing switching actions for prescribed data packets, and templates that specify frame data parameters for identifying the prescribed data packets. Each network switch, configured for performing layer and layer switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes in each network switch port a packet classifier module configured for classifying a received data packet based on a template generated based on the policy messages. In particular, the network switch stores a plurality of user-programmable templates, each configured for identifying a corresponding class of data packet.

System and method for network management of local area networks having non-blocking network switches configured for switching data packets between subnetworks based on management policies

A gigabit network node having a media access controller outputting data frames at gigabit rates uses multiple 100 MB/s media interface links coupled to a physical interface to enable implementation of a gigabit network using low cost data links. A modified reconciliation layer, also referred to as a media interface, receives a data frame from a gigabit MAC and selectively stores the received packet data into one of a plurality of transmit buffers associated with the respective 100 MB/s media interface links, according to a path selection arbitration logic in the media interface. The path selection arbitration logic may operate according to an equal priority scheme, where each received data frame is routed according to a round-robin scheme. A high priority/low priority scheme may also be used by the path selection arbitration logic, where data frames identified as high priority are temporarily stored in a high priority transmit buffer, and then forwarded to a selected one of the transmit buffers associated with a corresponding 100 MB/s media interface link before outputting data frames from a low priority buffer.

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San Jose, CA, United States of America

Gopal S Krishna