Abstract: 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.

Abstract: 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.

Abstract: Hardware-enforced zoning is provided in Fibre Channel switches to protect against breaching of assigned zones in a switch network which can occur with software-based zoning techniques. The invention provides logic for performing a hardware-based validation of the Source ID S_ID of frames both at the point where the frame enters the Fibre Channel fabric, and at the point where the frame leaves the fabric. The S_ID is verified against an inclusion list or table of allowable S_IDs, which can be unique for each fabric port. The invention provides a way to increase the range of sources an inclusion table can express, by implementing wild cards, on an entry-by entry basis. If the S_ID is valid, it will enter the fabric and route normally. If invalid, the frame will not be routed but will be disposed of by the fabric according to FC rules.

Abstract: A method and system for processing received and transmit data by an application specific integrated circuit (ASIC) from a network link. The method for received data includes swapping received data polarity if swap-polarity ability is set and swapping byte lanes for the received data if swap-lane ability is set. The method for transmit data includes swapping byte lanes for transmit data, if swap-byte lane ability is set and swapping data polarity if swap-polarity ability is set. The ASIC includes a network connector that receives and transmits data from the network link.

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

Abstract: Method and system for routing fiber channel frames using a fiber channel switch element is provided. The method includes, inserting a time stamp value in a fiber channel frame that is received at a receive segment of the fibre channel switch element; determining if a timeout occurs after a frame arrives at a receive buffer; and processing the frame if the timeout occurred. The method also includes, determining if a delta time value, which provides an accumulated wait time for a frame, is present in frame data; subtracting the delta time stamp value from a global time stamp value and using the resulting time stamp value to determine frame timeout status in the fiber channel switch element. A timeout checker circuit declares a timeout after comparing a time stamp value that is inserted in a fiber channel frame with a programmed time out value and a global counter value.

Abstract: A method and system for routing fiber channel frames using a fiber channel switch element is provided. The switch element includes, a hashing module whose output is used to select the column from a look up table to route frames. The method includes, indexing a look up table using domain, area, virtual storage area network identifier, a hashing module output and/or AL_PA values; selecting a column from the look up table based on a column select signal; and routing a frame if a route is valid. The hashing module takes a fiber channel header to generate a pseudo random value used for selecting a column from the look up table. The hashing module uses same field values in an exchange to generate the pseudo random value. A hash function is used on a frame's OX_ID, D_ID, S_ID, and/or RX_ID to route fiber channel frames.

Abstract: A method for assigning virtual lanes (VL) in a fibre channel switch is provided. The fibre 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.

Abstract: 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.

Abstract: A method and system for routing fibre channel frames using a fibre channel switch element is provided. The switch element includes, a hashing module whose output is used to select the column from a look up table to route frames. The method includes, indexing a look up table using domain, area, virtual storage area network identifier, a hashing module output and/or AL_PA values; selecting a column from the look up table based on a column select signal; and routing a frame if a route is valid. The hashing module takes a fibre channel header to generate a pseudo random value used for selecting a column from the look up table. The hashing module uses same field values in an exchange to generate the pseudo random value. A hash function is used on a frame's OX_ID, D_ID, S_ID, and/or RX_ID to route fibre channel frames.

Abstract: A method and system for routing fibre channel frames using a fibre channel switch element is provided. The switch element includes, a look up table that is indexed by domain, area, a virtual storage area number and/or AL_PA values of frames entering the fibre channel switch element; and logic for generating a column select signal that is used to select a column from the look up table for frame routing information The switch element also includes logic for validating a frame route by performing word depth match. A register is used to load look up table entries and column entries are selected based on the column select signal. The method includes, indexing a look up table with plural fibre channel frame header values; selecting a table value for routing a fibre channel frame based on a column select signal; and routing the frame if a route is valid.

Abstract: A fibre channel switch element for routing fibre channel frame is provided. The switch element includes a fibre channel port that can be configured to support plural data transfer rates. The data transfer rate may be 1 G, 2 G, 4 G, 8 G or 10 G. The switch element includes a clock configuration module for providing a clock signal that is based on the data transfer rate. A receive segment of the fibre channel port sends a signal to a transmit segment to avoid an under flow condition. The receive segment also waits for a certain frame length after a fibre channel frame is written and before the fibre channel frame is read, depending upon a data transfer rate of a source port. Multiple lanes may be configured as a single 10G multi lane port or as multiple individual ports.

Abstract: 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.

Abstract: A method for credit management in a network system is provided. The method comprises receiving an incoming frame at a receive port of a network device; determining a frame length of the incoming frame; based on the frame length, determining whether to store the frame in a first memory storage space or a second memory storage space, wherein the first memory storage space includes a plurality of slots and each of the plurality of slots can store only one frame regardless of frame size; and the second memory storage space includes a plurality of slots and each of the plurality of slots can store more than one frame; and if the incoming frame is stored in the second memory storage space, transmitting a signal immediately to another port indicating that credit is available.

Abstract: 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.

Abstract: A method for routing fibre channel frames using a fibre channel switch element is provided. The switch element includes, a receiving segment in a fibre channel port for receiving the frames and a transmit segment that transmits the received frames. The method includes requesting an early frame transfer, wherein the transmit segment of a fibre channel port requests an early frame transfer from a receiving segment of the fibre channel port before a frame has arrived at the transmit segment; activating an early frame transfer; determining if there is a need for aborting the early frame transfer request; and selecting a different source port if there is a need for aborting an early frame transfer request.

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

Abstract: A method and system for routing fiber channel frames using a fiber channel switch element is provided. The switch element includes, a look up table that is indexed by domain, area, a virtual storage area number and/or AL_PA values of frames entering the fiber channel switch element; and logic for generating a column select signal that is used to select a column from the look up table for frame routing information. The switch element also includes logic for validating a frame route by performing word depth match. A register is used to load look up table entries and column entries are selected based on the column select signal. The method includes, indexing a look up table with plural fiber channel frame header values; selecting a table value for routing a fiber channel frame based on a column select signal; and routing the frame if a route is valid.

Abstract: A fiber channel switch element for routing fiber channel frame is provided. The switch element includes a fiber channel port that can be configured to support plural data transfer rates. The data transfer rate may be 1 G, 2 G, 4 G, 8 G or 10 G. The switch element includes a clock configuration module for providing a clock signal that is based on the data transfer rate. A receive segment of the fiber channel port sends a signal to a transmit segment to avoid an under flow condition. The receive segment also waits for a certain frame length after a fiber channel frame is written and before the fiber channel frame is read, depending upon a data transfer rate of a source port. Multiple lanes may be configured as a single 10 G multi lane port or as multiple individual ports.

Abstract: A method and system for implementing LUN based hard zoning in a fibre channel network is provided. A LUN field in a Fibre Channel SCSI command frame is compared with a list of LUNS that are allowed for a particular frame source; and the frame is forwarded if the LUN is allowed for the frame source. The comparison is performed by a port receiving the frame by using an address look up table (“ALUT”). Hard zoning is based on various frame fields and/or ALUT control codes. Also provided is a method for processing a reply to a SCSI REPORT LUN command from an initiator. The method includes, intercepting a reply to a REPORT LUN command; editing the reply to remove unauthorized LUNs; and sending the edited reply to the initiator.