Texas Instruments Corporation

Barefoot Networks, Inc.

Other

Patrick W Bosshart

Michael Gregory Ferrara

Jay Evan Scott Peterson

Hun-Seok Kim

Changhoon Kim

Anurag Agrawal

Theodore Warren Houston

Michael E Attig

Jay E S Peterson

Masoud Moshref Javadi

Jeongkeun Lee

Douglas J Matzke

Jonathan H Shiell

Sanjive Agarwala

Steven Licking

Ching-Hao Shaw

Vibhu Kalyan

Daniel Charles Pickens

Remy Chang

Keerthinarayan P Heragu

Mitra Nasserbakht

David Barry Scott

Uming U Ko

Tod David Wolf

Chaitanya Kodeboyina

Derek J Smith

James D Gallia

Sandeep Bhadra

Aman A Kokrady

Ravindra Sunkad

Paul Eric Landman

Quang Dieu An

Van Minh Nguyen

Pranjal Srivastava

Ching-Heo Shaw

David R Shoemaker

Some embodiments provide a method for processing a packet for a pipeline of a hardware switch. The pipeline, in some embodiments, includes several different stages that match against packet header fields and modify packet header fields. The method receives a packet that includes a set of packet headers. The method then populates, for each packet header in the set of packet headers, (i) a first set of registers with packet header field values of the packet header that are used in the pipeline, and (ii) a second set of registers with packet header field values of the packet header that are not used in the pipeline.

Packet header field extraction

A method for generating configuration data for configuring a hardware switch is described. The method receives a description of functionality for the hardware switch. Based on the description, the method generates sets of match and action entries to configure the hardware switch to process packets. The method then determines, for each packet header field in a parse graph that specifies instructions for a parser of the switch to extract packet header fields from packets, whether the packet header field is used or modified by at least one match or action entry. The method generates for the parser of the hardware switch configuration data that instructs the parser to extract (i) packet header fields used or modified by at least one match or action entry to a first set of registers and (ii) packet header fields not used by any match or action entries to a second set of registers.

Configuring a switch for extracting packet header fields

Some embodiments provide a network forwarding IC with packet processing pipelines, at least one of which includes a parser, a set of match-action stages, and a deparser. The parser is configured to receive a packet and generate a PHV including a first number of data containers storing data for the packet. A first match-action stage is configured to receive the PHV from the parser and expand the PHV to a second, larger number of data containers storing data for the packet. Each of a set of intermediate match-action stage is configured to receive the expanded PHV from a previous stage and provide the expanded PHV to a subsequent stage. A final match-action stage is configured to receive the expanded PHV and reduce the PHV to the first number of data containers. The deparser is configured to receive the reduced PHV from the final match-action stage and reconstruct the packet.

Expansion of packet data within processing pipeline

An algorithmic TCAM based ternary lookup method is provided. The method stores entries for ternary lookup into several sub-tables. All entries in each sub-table have a sub-table key that includes the same common portion of the entry. No two sub-tables are associated with the same sub-table key. The method stores the keys in a sub-table keys table in TCAM. Each key has a different priority. The method stores the entries for each sub-table in random access memory. Each entry in a sub-table has a different priority. The method receives a search request to perform a ternary lookup for an input data item. A ternary lookup into the ternary sub-table key table stored in TCAM is performed to retrieve a sub-table index. The method performs a ternary lookup across the entries of the sub-table associated with the retrieved index to identify the highest priority matched entry for the input data item.

Algorithmic TCAM based ternary lookup

A method of identifying a path for forwarding a packet by a packet forwarding element. The method receives a packet that includes a plurality of fields that identify a particular packet flow. The method computes a plurality of hash values from the plurality of fields that identify the particular packet flow. Each hash value computed using a different hash algorithm. Based on the plurality of hash values, the method identifies a plurality of paths configured to forward the packets of the particular flow. The method identifies the status of each of the plurality of paths. Each path status identifies whether or not the corresponding path is operational. The method selects an operational path in the plurality of paths to forward the packet based on a priority scheme using said plurality of identified status bits.

Resilient hashing for forwarding packets

Some embodiments provide a network forwarding element with a data-plane forwarding circuit that has a parameter collecting circuit to store and distribute parameter values computed by several machines in a network. In some embodiments, the machines perform distributed computing operations, and the parameter values that compute are parameter values associated with the distributed computing operations. The parameter collecting circuit of the data-plane forwarding circuit (data plane) in some embodiments (1) stores a set of parameter values computed and sent by a first set of machines, and (2) distributes the collected parameter values to a second set of machines once it has collected the set of parameter values from all the machines in the first set. The first and second sets of machines are the same set of machines in some embodiments, while they are different sets of machines (e.g., one set has at least one machine that is not in the other set) in other embodiments. In some embodiments, the parameter collecting circuit performs computations on the parameter values that it collects and distributes the result of the computations once it has processed all the parameter values distributed by the first set of machines. The computations are aggregating operations (e.g., adding, averaging, etc.) that combine corresponding subset of parameter values distributed by the first set of machines.

Forwarding element data plane performing floating point computations

Forwarding element data plane with computing parameter distributor

Some embodiments provide a network forwarding integrated circuit (IC) that includes at least one packet processing pipeline. The packet processing pipeline includes multiple match-action stages, at least one of which includes a stateful processing unit that operates at a line rate of the network forwarding IC. The stateful processing unit is configured to receive data stored in a memory location associated with a stateful table of the match-action stage. The data includes a set of values. The stateful processing unit is further configured to identify one of a maximum value and a minimum value from the set of values, and to output the identified value for use by a next match-action stage.

Stateful processing unit with min/max capability

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Plano, TX, United States of America

Patrick W Bosshart