Cisco Technology, Inc.

Other

Cortina Systems Corporation

Oded Trainin

Mark Andrew Gustlin

Eyal Oren

Mohammed Ismael Tatar

Garry Paul Epps

Cedrik K Begin

Luca Della Chiesa

John Joseph Williams, Jr

Yiren Huang

Raymond Kloth

Ryan Patrick Donohue

Med Belhadj

Paul Lachlan Mantiply

Peter Malcolm Barnes

Gil Goren

Sebastian H Ziesler

Jason Alexander Jones

Fredrick Karl Olive Olsson

Rami Zecharia

James Brian Mckeon

Gregory Alan Bryant

Dov A Freund

Gary Steven Singer

In one embodiment, an apparatus includes n electrical communication channels, m optical communication media interfaces, and a plurality of muxes. The plurality of muxes are configured to receive an information stream. The information stream is carried over the n electrical communication channels and the m optical communication media interfaces. The plurality of muxes are further configured to transform the information stream from v virtual lanes. Each virtual lane includes a plurality of data blocks from the information stream and an alignment block, wherein v is a positive integer multiple of the least common multiple of m and n, v is greater than n, and n is equal to m.

System and method for providing an ethernet interface

In one embodiment, an apparatus includes n electrical communication channels, m optical communication media interfaces, and a plurality of muxes. The plurality of muxes are configured to receive an information stream, the information stream carried over the n electrical communication channels and the m optical communication media interfaces. The plurality of muxes are further configured to transform the information stream from v virtual lanes, each virtual lane comprising a plurality of data blocks from the information stream and an alignment block, wherein v is a positive integer multiple of the least common multiple of m and n.

Techniques for reducing latency associated with metaframe error correction. Embodiments receive, via a first port of a plurality of ports, a stream of bits within a metaframe. Upon evaluating a first cyclic redundancy check (CRC) for a first portion of the stream of bits and determining that the first CRC is valid, a measure of latency incurred in transmitting the first portion is reduced, relative to first performing forward error correction (FEC) decoding for the first portion prior to transmission, by transmitting the first portion of the stream of bits without performing FEC decoding for the first portion of the stream of bits. Upon evaluating a second CRC for a second portion of the stream of bits and determining that the second CRC is invalid, FEC decoding is performed for the second portion of the stream of bits before forwarding the second portion of the stream of bits.

Minimum latency link layer metaframing and error correction

An apparatus is provided that includes communication channels, and m communication media interfaces, and v virtual lanes. V is a positive integer multiple of the least common multiple of m and n. An information stream is transferred into data and alignment blocks striped across all of the v virtual lanes, the blocks being communicated from the virtual lanes onto the communication channels. The blocks are received on the communication channels. Each of the communication channels transmits a different portion of the blocks striped across all of the v virtual lanes. In more particular embodiments, v&#x3e;=n&#x3e;=m. The communication media interfaces can be electrical and optical. Each of the communication channels can include a SerDes interface operating at least 5 Gigabits per second. Furthermore, each of the m communication media interfaces is configured to transmit a different stream of information over a single optical fiber.

System and method for providing an Ethernet interface

Embodiments generally provide techniques for data framing and error correction for communications on a link. Embodiments include receiving a stream of bits within a metaframe. Upon determining that a cyclic redundancy check (CRC) for a portion of the stream of bits is valid, the portion of the stream of bits is forwarded without performing forward error correction (FEC) decoding for the first portion. Upon determining that a CRC for the portion of the stream of bits is invalid, FEC decoding is performed for the portion before forwarding the portion of the stream of bits. Embodiments also include generating a metaframe for transmission over a link, and upon determining that a current measure of network throughput is less than a predefined threshold amount of network throughput, inserting one or more checkpoints into the metaframe to create different segments of the metaframe. The metaframe is then transmitted over the link.

An apparatus is provided that includes n communication channels, and m communication media interfaces, and v virtual lanes. V is a positive integer multiple of the least common multiple of m and n. An information stream is transferred into data and alignment blocks striped across all of the v virtual lanes, the blocks being communicated from the virtual lanes onto the communication channels. The blocks are received on the communication channels. Each of the communication channels transmits a different portion of the blocks striped across all of the v virtual lanes. In more particular embodiments, v&#x3e;=n&#x3e;=m. The communication media interfaces can be electrical and optical. Each of the communication channels can include a SerDes interface operating at least 5 Gigabits per second. Furthermore, each of the m communication media interfaces is configured to transmit a different stream of information over a single optical fiber.

To calculate sequential CRCs, a CRC pipeline may be used to calculate the sequential CRCs for a block of data The CRC pipeline includes a plurality of stages, where, in each subsequent stage a CRC calculated from a previous stage is used to calculate an offset CRC. For example, using at least one CRC calculator and CRC shifter, a stage in the pipeline removes an effect of first portion of the data represented by a previously calculated CRC from the CRC and then adds an effect of a second portion of data neighboring the first portion in a received data block to yield an offset CRC. For example, a stage may change CRC(0:63) to CRC(32:95) by removing the effect of bytes 0:31 and adding the effect of bytes 64:95. At each stage, the byte offset may get smaller until all the sequential CRCs have been calculated.

Calculating cyclic redundancy checks over overlapping windows of streaming data

An architecture for a line card in a network routing device is provided. The line card architecture provides a bi-directional interface between the routing device and a network, both receiving packets from the network and transmitting the packets to the network through one or more connecting ports. In both the receive and transmit path, packets processing and routing in a multi-stage, parallel pipeline that can operate on several packets at the same time to determine each packet's routing destination is provided. Once a routing destination determination is made, the line card architecture provides for each received packet to be modified to contain new routing information and additional header data to facilitate packet transmission through the switching fabric. The line card architecture further provides for the use of bandwidth management techniques in order to buffer and enqueue each packet for transmission through the switching fabric to a corresponding destination port. The transmit path of the line card architecture further incorporates additional features for treatment and replication of multicast packets.

Pipelined packet switching and queuing architecture

A high speed multi-lane serial interface and method for constructing frames for such an interface are provided. Frames are constructed for transmission on a multi-lane serial interface. For each of a plurality of transmit channels, packets are fragmented into fragments. Meta-frames are generated having a size defined by a constant meta-frame length&#xd7;number of lanes, each frame having a meta-frame separator and a payload. Per-transmit channel flow control information is received. Each payload has a plurality of bursts, each burst comprising a burst control word and an associated data burst, the burst control word identifying one of said transmit channels to be transmitted on the associated data burst, each data burst comprising one of the fragments for the transmit channel identified in the associated burst control word. The channels to transmit in a given meta-frame are selected as a function of the received flow control information.

High speed packet interface and method

Methods and apparatus are disclosed for generating a result based on a lookup result from a lookup operation using an associative memory and processing based on a discriminator portion of a lookup word. A first lookup operation is performed to generate a lookup result. In one implementation, a second lookup operation is performed based on a discriminator or the lookup result depending on the result of an evaluation, such as whether there was a hit or the lookup result matches a predetermined value. In one implementation, a second lookup operation is performed based on the discriminator, and either the result of the first or second lookup operation is used for subsequent processing. One implementation performs a lookup operation based on a lookup word to generate a lookup result, which is used to retrieve a base address and a bitmap from a memory. A discriminator is identified, and the result is generated based on the discriminator, the bitmap, and the base address, such as by adding to the base address the number of set bits in a range within the bitmap.

Methods and apparatus for generating a result based on a lookup result from a lookup operation using an associative memory and processing based on a discriminator portion of a lookup word

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Raanana, Israel

Oded Trainin