Qlogic Corporation

Craig M Verba

Frank R Dropps

Gary M Papenfuss

Ernest G Kohlwey

Edward C Ross

Mark Alan Owen

James Kunz

Leo J Slechta, Jr

William J Andersen

Thomas R Prohofsky

James A Kunz

Mark A Owen

Methods and systems for a network device. The network device includes a temporary memory storage device having a plurality of storage locations that are used to store packets received by a plurality of sub-ports. The network device includes a cut-through estimation circuit that estimates a cut-through threshold value based on which a certain portion of a packet has to be received and stored at one of the plurality of storage locations before the packet can be processed by one of the sub-ports that received the frame. The cut-through threshold value varies based on an operating speed of a network link the packet is received on, an operating speed of a network link the packet is transmitted on, and a protocol used for receiving and transmitting the packet.

Cut-through routing for network devices

A network device and associated methods are provided. The network device includes a routing module having a ternary content addressable memory (TCAM) module maintained for storing a plurality of entries for routing frames that are received for a plurality of sub-ports complying with a plurality of protocols; a steering action memory that stores a plurality of steering action codes associated with the plurality of TCAM entries for tossing frames, rejecting frames and providing them to a processor for the network device, indicating that a destination is valid, and indicating to use another routing mechanism; and a steering mechanism that is used when a received frame information does not match with the TCAM entries and the received frame is of a certain protocol type.

Systems and methods for routing by network devices

Method and system for configuring a port of a network device are provided. One method for a port of a network device communicating with another network device port includes reading manufacturing, license and user provided port configuration data by a processor of the network device; obtaining capabilities information for the port by the processor of the network device from an external pluggable media device; setting port configuration data based on the capabilities information obtained from the external pluggable media; executing auto-negotiation on the port, when enabled and obtaining configuration data from the other port; determining that enough data is available to set port configuration; attempting to configure the port by using a highest permissible bandwidth configuration when enough data is available to set the port configuration; and setting port configuration based on the attempt to configure the port to operate when a link connected to the port is operational.

Network devices having configurable receive packet queues and related methods

Methods and systems for packet grouping in a network are provided. A packet is received at a receive segment of a port of a first network device for transmission to a destination port of a second network device. The port determines if the packet is a start packet of a packet sequence. When the packet is not the start packet of the packet sequence, the port determines whether the packet has a destination that is the same as a destination of a last prior packet. When the packet is for the same destination, a grouping count is increased and the packet priority is elevated.

Systems and methods for packet grouping in networks

A method and system for routing frames based on a port's speed using a switch element. The method includes receiving a portion of a frame in a receive buffer of a port; determining a frame length threshold value; and setting up a status bit based on the port's speed, the frame length threshold value and an amount of the frame received. The status bit is sent to a transmit segment of the switch element and the frame length threshold value is proportional to the port's speed. Also, if the receive buffer is almost full when the frame arrives at the receive port, then a cut status is based on the frame's end of frame ('EOF') value.

Multi-speed cut through operation in fibre channel switches

Method and system for network communication including identifying a first network port to be taken offline. Before taking the first network port offline, processing any pending packet tag for the first network port. The method further includes taking the first network port offline; storing a packet tag destined for the first network port at the second network port, while the first network port is offline; bringing the first network port online; and routing the packet tag stored at the second network port, while the first network port was offline; wherein the packet tag is routed from the second network port to the first network port.

Method and system for taking a network port offline

Method and system for configuring a receive packet queue in a network device are provided. The method includes determining how many sub-ports of a port of the network device are configured; assigning memory to each of the configured sub-ports based on the determination of how many sub-ports are configured; determining a flow control scheme to be used for packet transmission; and dividing the receive packet queue based on the determination of the flow control scheme to be used.

One method includes: (a) providing a memory storage device having a plurality of storage locations for storing information received by a plurality of sub-ports of a base port of the network device, where the memory storage device is shared among the plurality of sub-ports such that each sub-port is given access to the memory storage device at a certain phase of a system clock cycle; (b) storing a packet or a portion thereof at one of the storage locations when a sub-port that receives the packet has access to one or more of the storage locations; and (c) scrambling addresses for the memory storage locations such that a different one of the storage location is available to the sub-port of step (b) for a next write operation in a next phase when the sub-port of step (b) is given access to the memory storage device.

Memory devices for network devices and associated methods

Methods and systems for a network device having a plurality of base-ports, each base-port having a plurality of sub-ports configured to operate independently as a port for sending and receiving information using one of a plurality of network links at a plurality of rates complying with a plurality of protocols. The network device includes a ternary content addressable memory (TCAM) module for storing a plurality of entries for routing frames that are received for the plurality of sub-ports complying with the plurality of protocols. Each TCAM entry has an associated history value that is used by a processor for the network device to purge TCAM entries based on an age of the TCAM entries.

Systems and methods for using TCAMs in network devices

Method and system for a network switch element is provided. The switch element includes a plurality of megaports, each megaport uniquely identified by a unique megaport address identifier for network addressing. Each megaport includes a plurality of operational ports, each operational port identified by a unique operational port address identifier. The switch element also includes a local crossbar for communication between the plurality of operational ports, and a shared logic module configured to provide common control of the plurality of operational ports within a megaport to allow operational ports to share resource of a single megaport to route network packets there between. The switch element also includes a global crossbar configured to allow communication between the megaports.

Method and system for network switch element

A fiber channel switch element and method for routing fiber channel frames is provided. The switch element includes a receive segment that can add a virtual storage area network ('VSAN') tagging header to frames that are received by the receive segment; and strip the VSAN tagging header before frames are sent to ports that do not support virtual fabric capability. The receive segment includes a table used for matching fabric extension parameters. An incoming frame's VSAN identity value is compared to a control word entry to generate a value used for routing the incoming frame. The table is used to determine if a frame is part of a virtual fabric. The routing table for each port is used to route frames and the routing table includes entries for supported virtual fabrics.

Method and system for using extended fabric features with fibre channel switch elements

A fibre channel switch element and method for routing fibre channel frames is provided. The switch element includes a receive segment that can add a virtual storage area network ('VSAN') tagging header to frames that are received by the receive segment; and strip the VSAN tagging header before frames are sent to ports that do not support virtual fabric capability. The receive segment includes a table used for matching fabric extension parameters. An incoming frame's VSAN identity value is compared to a control word entry to generate a value used for routing the incoming frame. The table is used to determine if a frame is part of a virtual fabric. The routing table for each port is used to route frames and the routing table includes entries for supported virtual fabrics.

Method and system for routing Fibre Channel frames is provided. The includes (a) receiving a frame at a port of a switch element; (b) determining if the frame is to be routed using extended area routing; (c) if extended area routing is to be used for routing the frame, identifying a source for obtaining extension bits for expanding an area identification field (Area_ID); and (d) expanding the Area_ID field using the extension bits from the identified source. The system includes routing logic at a port of a switch element for performing the foregoing steps.

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Maple Grove, MN, United States of America

Craig M Verba