Qlogic Corporation

Edward C Ross

Frank R Dropps

Ernest G Kohlwey

Craig M Verba

Gary M Papenfuss

Mark Alan Owen

James Kunz

Steven Manning Betker

William J Gustafson

Leo J Slechta, Jr

Bret E Indrelee

James A Kunz

Mark A Owen

Method and system for reporting out-of-credit condition for a network device connected to a network. An indication to an out-of credit logic is provided that a first sub-port operating using a first protocol is out of credit to transmit information from a transmit segment. The first sub-port is a part of a base-port that includes a plurality of sub-ports that can be configured to operate at more than one operating speed to process packets complying with different protocols. The out-of-credit logic determines when the first sub-port is out-of-credit for a threshold period of time, and reports that the sub-port is out-of-credit to a processor of the network device.

Methods and systems for an out-of-credit timer in a network device

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

Method and system for processing a management operation command received from a management entity is provided. The management operation command is received by an emulation module for a switch element operationally coupled to the management entity. The switch element includes a plurality of ports, each port having a plurality of components designated as managements devices. The emulation module determines if identification information for a management device in the command matches with identification information stored by the switch element to emulate the management device. If the information matches, then the management operation identified in the management operation command is performed by the emulation module interfacing with a switch element processor.

Emulation of multiple MDIO manageable devices

A method for assigning virtual lanes (VL) in a fiber channel switch is provided. The fiber channel switch element includes a virtual lane cache that can compare incoming frame parameters based on which virtual lanes may be assigned; and a register to store parameters used for virtual lane assignment. The method includes, determining if VL assignment is to be based on an incoming frame parameter or a programmed value; determining if an incoming frame is a preferred frame; and assigning a preferred routing priority if the incoming frame is designated as a preferred frame. The method also includes, determining if a fabric topology is known; and assigning virtual lanes based on a known fabric topology.

Method and system for selecting virtual lanes in fibre channel switches

A method and system for distributing credit using a fiber channel switch element is provided. The switch element includes, a wait threshold counter that is used to set up a status for a port that has to wait for certain duration to send a frame due to lack of buffer to buffer credit; a credit module that controls buffer to buffer credit for a transmit segment of the fiber channel switch element; and a virtual lane credit module with a counter that is incremented every time a frame assigned to a virtual lane is sent and decreased every time a VC_RDY is received. The method includes, determining if a VC_RDY primitive is received; and allocating credit to a virtual lane that is not at its maximum credit, after the VC_RDY primitive is received.

Method and system for buffer-to-buffer credit recovery in fibre channel systems using virtual and/or pseudo virtual lanes

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.

A fiber channel switch element with an alias cache is provided for routing and filtering frames. The alias cache includes plural entries including a control word having plural fields including an action code for routing frames; an alias word that is compared to incoming frame data using a frame byte compare block; and a bit mask generator for filtering bit combinations from the frame byte compare block; and a depth match block for determining equality between a control word depth field and incoming frame depth field. Frame data comparison is performed on a bit by bit or byte-by-byte basis. An alias cache entry also includes prerequisite data to determine if results of a different entry are to be used to determine an entry match. The action code routes a frame to a processor, discards a frame, sets a status for inspecting a frame or routes a frame based on a standard Fiber Channel addressing scheme.

Method and system for routing and filtering network data packets in fibre channel systems

A method and switch element for assigning priority to pseudo virtual lanes ('PVL') using a fibre channel switch element is provided. The method includes, assigning received R_RDYs based on a PVL distribution scheme; and determining traffic congestion on a PVL if there is no credit available to transfer frames from the PVL. A minimum bandwidth feature is enabled to avoid lower priority PVLs from getting no credit for transmitting frames; and distributing credit and R_RDYs based on frame age bits, wherein a lower priority PVL gets credit if a frame is waiting in the PVL for a longer duration compared to a higher priority PVL. The switch element includes, a PVL module having credit counters for plural PVLs; and a timer that monitors frame traffic for each PVL lane. If a PVL gets congested, then a state machine adjusts priority of R_RDY distribution scheme of other PVLs to transmit frames.

Programmable pseudo virtual lanes for fibre channel systems

Method and system for distributing credit in fibre channel systems

Method and system for processing frames in a Fibre Channel network is provided. The method includes receiving a frame at a receive port; determining if a translation cache is enabled; determining if there is a match between a received frame header and an entry in the translation cache; generating an encapsulation signal, a de-encapsulation signal, a translation signal or a routing signal; removing data words in the received frame header, if de-encapsulation signal is set; translating the received frame header, if the translation signal is set; encapsulating the frame with an encapsulation header, if the encapsulation signal is set; and routing the frame using translation cache routing if the routing signal is set.

Method and system for routing network information

A Fibre Channel switch element in a Fibre Channel network is provided. The Fibre Channel switch element includes a port that replaces a logical unit number ('LUN') field value in a FCP_CMND frame. The port includes a LUN Mapping cache for replacing the LUN field value in a FCP_CMND frame. The LUN Mapping cache may also generate a value that is added to or subtracted from the LUN field value in the FCP_CMND frame. A control bit is used to activate LUN Mapping cache for mapping LUN values.

Method and system for LUN remapping in fibre channel networks

Method and system for checking frame-length in a Fiber Channel frames is provided. The method includes extracting a R_CTL value from a Fiber Channel frame; comparing the extracted R_CTL value of the Fiber Channel frame with R_CTL values stored in a Content Addressable Memory Table; determining a maximum frame-length and a minimum frame-length of the Fiber Channel frame for the extracted R_CTL value from the Content Addressable Memory Table; and marking the Fiber Channel frame so that it can be discarded if the frame-length is less than the minimum frame-length of the Fiber Channel frame or greater than the maximum frame-length of the Fiber Channel frame. The system includes a processor that accesses a CAM stored in memory; and a receive port that extracts and compares a R_CTL value of the Fiber Channel frame.

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Edina, MN, United States of America

Edward C Ross