Ixia

Keysight Technologies, Inc.

Keysight Technologies Singapore (holdings) Pte. Ltd.

Xircom, Inc.

Keysight Technologies Singapore Pte. Ltd.

Gerald Raymond Pepper

Bryan Rittmeyer

John Dalmau

Errol Ginsberg

Manley Klassen

Alon Regev

Noah Steven Gintis

Clifford Lee Hannel

Robert Brian Luking

Dwayne Hunnicutt

Douglas E Schafer

Bruce Bockwoldt

Brian Adam Wilson

Viet Quoc Tran

Sanjay Cartic

Sushil S Kamerkar

Limin Liu

Anup Jethra

Matthew Ryan Bergeron

Ian A Laity

Michael D Hutchison

Victor Alston

James G Hughes

Donald C Barrett

Brian Fuchs

Johnny Tsung Lin Ho

Hadrien Louchet

Marie Stanek Wyszynski

Frank McLinn

A method for reconstructing uncorrectable forward error correction (FEC) data includes generating and transcoding a known bit sequence and transmitting a FEC encoded codeword that includes a payload containing the transcoded known bit sequence through a component under test. The method further includes receiving the FEC encoded codeword transmitted via the component under test and determining that the encoded contents of the FEC encoded codeword contains a number of symbol errors that exceeds a predefined threshold. The method also includes utilizing stored scramble seed bits corresponding to an immediately preceding FEC encoded codeword and the transcoded known bit sequence to generate a reconstructed codeword.

Methods, systems and computer readable media for reconstructing uncorrectable forward error correction (FEC) data

Conventional test systems can experience issues when attempting to test network nodes or system with realistic high speed forward error correction (FEC) encoded test data. For example, a test system may use a packet data generator to generate eight data streams or lanes of 50 Gigabits per second (Gbps) test data and may then use a multiplexer to combine the eight lanes into a 400 Gbps data stream for transmission using 4-level pulse amplitude modulation (PAM4). To generate a high speed data stream comprising multiple data lanes, the test system may be required to use a master clock or other time synchronization technique to keep the data lanes in sync. Further, to generate an FEC encoded high speed data stream comprising multiple data lanes, the test system may perform FEC encoding across all of the data lanes comprising the high speed data stream, which can make test data modifications difficult afterwards. Hence, issues can arise if a packet data generator lacks capabilities, e.g., analog distortion or analog fuzzing features, that are needed for testing some aspect of network node functionality.

Methods, systems, and computer readable media for generating analog-distorted test data

According to one method for obtaining information from a hardened forward error correction (FEC) implementation, the method occurs at a test device implemented using at least one processor and at least one memory. The method includes copying data from a data stream that is to be processed by a hardened FEC engine; delaying the copied data while the hardened FEC engine generates corresponding error corrected output using the data; comparing the copied data and the corresponding error corrected output for differences; and generating FEC related metrics based on the comparison.

Methods, systems, and computer readable media for testing of hardened forward error correction (FEC) implementations

A method for transmit timestamp autocalibration includes generating a calibration pulse for calibrating a transmit timestamp in a transmitting device. The method further includes applying the calibration pulse to a transmit data pipeline in the transmitting device. The method further includes sampling a transmit timestamp when the calibration pulse reaches a timestamp sample triggering location in the transmit data pipeline upstream from an egress point of the transmitting device. The method further includes measuring a latency between a time that the calibration pulse reaches the timestamp sample triggering location and a time that the calibration pulse reaches a location downstream from the timestamp sample triggering location. The method further includes generating an adjusted timestamp based on the measured latency and inserting the adjusted timestamp into a data packet to be transmitted from the transmitting device.

Methods, systems, and computer readable media for transmit timestamp autocalibration

A method for evaluating link or component quality using synthetic forward error correction (FEC) includes generating a bit sequence. The method further includes transmitting the bit sequence over a link or through a component under test without adding FEC to the bit sequence. The method further includes receiving a bit sequence transmitted over the link or through the component. The method further includes determining locations of bit errors in the received bit sequence. The method further includes determining locations of synthetic FEC codeword and symbol boundaries in the received bit sequence for the synthetic FEC algorithm against which link or component quality is being evaluated. The method further includes identifying symbol and codeword errors for the synthetic FEC algorithm based on the locations of bit errors in received bit sequence. The method further includes outputting an indication of link or component quality based on the symbol and codeword errors identified for the synthetic FEC algorithm.

Methods, systems and computer readable media for evaluating link or component quality using synthetic forward error correction (FEC)

A method for wide bus pattern matching includes, receiving, in a first clock cycle, a bus width of data from a data bus. The method further includes using pattern compare blocks to compare each n-bit portion of data from the data bus to a plurality of different n-bit pattern portions, n being an integer equal to a smallest boundary in which a pattern can start on the data bus. The method further includes detecting, using a plurality of diagonal detectors, matching pattern portions across the pattern compare blocks that are arranged in a diagonal. The method further includes detecting, using a packet boundary detector, when the matching pattern portions arranged in a diagonal indicate a matching pattern that falls within a set of packet boundaries. The method further includes indicating a positive match when the packet boundary detector indicates that the matching.

Methods, systems and computer readable media for wide bus pattern matching

A method for transmitting and coherently detecting data transmitted over electrical lanes that experience different amounts of skew includes, at a traffic generation or forwarding device, self calibrating transmit and receive-side components of the traffic generation or forwarding device to account for skew between electrical lanes and setting per-electrical lane delays based on the calibration. Data to be transmitted to a network device is generated. The data to be transmitted is spread, using one of the transmit-side components, over a first number of electrical lanes. The data is multiplexed from the electrical lanes onto a second number of optical lanes, the second number being different from the first number. Data is transmitted to and received from the network device over the optical lanes. Transmitted data is reconstructed from the received data using the receive-side components.

Methods, systems, and computer readable media for providing traffic generation or forwarding device that compensates for skew between electrical lanes in a manner that allows coherent detection of transmitted data

The subject matter described herein includes methods, systems, and computer readable media for efficiently scrambling data in high speed communications networks. One exemplary method includes, in a network equipment test device, providing a scrambler for scrambling data to be transmitted to a device under test. Scrambling the data includes separating a scrambling algorithm into a scramble key portion and a data portion. Scrambling the data further includes pre computing and storing the scramble key portion. Scrambling the data further includes precomputing and storing the data portion. Scrambling the data further includes logically combining the precomputed scramble key portion with the precomputed data portion to produce a data bus width scrambled output data. The method further includes transmitting the scrambled output data over a network to the device under test.

Methods, systems, and computer readable media for efficient scrambling of data for line rate transmission in high speed communications networks

Methods, systems, and computer readable media for a multi-packet CRC engine are disclosed. According to one aspect, the subject matter described herein includes a system for a multi-packet CRC engine. The system includes an input module for receiving set of bits associated with at least one data packet and identifying packet boundaries within the plurality of bits, multiple CRC pre-calculation blocks (CPBs) that receive from the input module subsets of the set of bits, each subset containing a portion of a packet less than all of a packet, and calculate a CRC value for its respective subset of bits, and an output module for receiving the calculated CRC values from the CPBs and using the calculated CRC values to produce packet-specific CRC values, where the output module is dynamically configurable to combine the calculated CRC values according to the identified packet boundaries to produce packet-specific CRC values.

Methods, systems, and computer readable media for multi-packet cyclic redundancy check engine

Methods, systems, and computer readable media for generating test packets in a network device using value lists caching are disclosed. In one method, value lists are stored in dynamic random access memory of a network test device. Each value lists includes values for user defined fields (UDFs) to be inserted in test packets. Portions of each value lists are read into per-port caches. The UDF values are drained from the per-port caches using per-port stream engines to generate and send streams of test packets to one or more devices under test. The per-port caches are refilled with portions of the value lists from the DRAM and a rate sufficient to maintain the sending of the stream engine packets to the one or more devices under test.

Methods, systems, and computer readable media for generating test packets in a network test device using value list caching

Traffic generators, methods, and computer readable storage media for testing a network are disclosed. A scheduler may determine a sequence of packets to be transmitted, each packet in the sequence of packets belonging to one of a plurality of flow control groups. A packet generator may generate packets in the determined sequence and output completed packets for transmission over a network under test. The packet generator may include a first processing engine and a last processing engine configured as a pipeline to perform respective sequential stages of a packet generation process, and a first bank of first-in-first-out (FIFO) queues including a plurality of FIFO queues corresponding to the plurality of flow control groups. The first processing engine may store first packet forming data associated with each flow control group in the corresponding FIFO queue of the first bank of FIFO queues.

Traffic generator with priority flow control

A method and system for measuring a convergence time of a network. Test traffic including a plurality of packet groups may be transmitted and received via the network. The network may be instructed to redirect packets belonging to a selected packet group from a first port of the network to a second port of the network. A first test port unit coupled to the first port may determine an arrival rate for the selected packet group and store a below threshold timestamp when the arrival rate first falls below a predetermined threshold rate. A second test port unit coupled to the second port may determine an arrival rate for the selected packet group and store an above threshold timestamp when the arrival rate first equals or exceeds the predetermined threshold rate. The convergence time may be determined based on the below threshold timestamp and the above threshold timestamp.

Method and system for measuring network convergence time

Apparatus, method, and storage medium for testing a network. A network card may include four transmit engines and four receive engines to respectively generate and process packets at a data rate of 10 GHz. The network card may be configured in a first mode to also include four 10 GHz network interface units coupled to respective ones of the four 10 GHz transmit engines and the four 10 GHz receive engines. The network card may be configured in a second mode to also include a coherent multiplexer to combine packets generated by the four 10 GHz transmit engines into test traffic at a 40 GHz data rate, a packet distribution engine to accept packets at a 40 GHz data rate and distribute the accepted packets between the four 10 GHz receive engines, and a 40 GHz network interface unit coupled to the coherent multiplexer and the packet distribution engine.

Flexible network test apparatus

Methods, traffic receivers, and computer readable storage media for testing network connections are disclosed. A traffic receiver coupled to a network under test may receive a packet. A packet group identification number (PGID and a sequence number (SN) may be extracted from the received packet. Data associated with the PGID may be retrieved from a memory, the data including a next expected sequence number (NESN), a start of run (SOR), a number of in-order packets (NIO) and a number of duplicate packets (NDP). When SN is equal to NESN, NESN and NIO may be incremented. When SN is less than NESN and SN is greater than or equal to SOR, NDP may be incremented. When SN is greater than NESN, SOR may be set to SN, NESN may be set to SN plus one, and NIO maybe incremented. Updated data may be stored in the memory.

Tracking packet sequence numbers

Port units, methods, and computer readable storage media for testing a network are disclosed. A traffic generator may generate and transmit test traffic over a network under test, the test traffic including a plurality of interleaved packet streams, each traffic stream associated with one of a plurality of flow control groups. A traffic receiver may receive flow control packets from the network under test. The traffic generator may be configured to stop transmission of all packet streams associated with one or more paused flow control groups when the traffic receiver receives a flow control packet identifying the one or more paused flow control groups.

Growing community of inventors

Newbury Park, CA, United States of America

Gerald Raymond Pepper