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Publication numberUS20070201457 A1
Publication typeApplication
Application numberUS 11/743,852
Publication date30 Aug 2007
Filing date3 May 2007
Priority date22 Jul 2002
Also published asUS7230929, US20040013092
Publication number11743852, 743852, US 2007/0201457 A1, US 2007/201457 A1, US 20070201457 A1, US 20070201457A1, US 2007201457 A1, US 2007201457A1, US-A1-20070201457, US-A1-2007201457, US2007/0201457A1, US2007/201457A1, US20070201457 A1, US20070201457A1, US2007201457 A1, US2007201457A1
InventorsSteven Betker, Timothy Vitters, Renae Weber
Original AssigneeBetker Steven M, Vitters Timothy R, Weber Renae M
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and system for dynamically assigning domain identification in a multi-module fibre channel switch
US 20070201457 A1
Abstract
A method for entering fabric configuration in a fibre channel system for a multi-module fibre channel switch is provided. The method includes determining if a primary blade has been selected for the multi-module switch; sending exchange fabric parameters to internal ports of the multi-module switch; and processing principal switch selection events.
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Claims(9)
1. A method for entering fabric configuration in a fibre channel system for a multi-module fibre channel switch, comprising:
determining if a primary blade has been selected for the multi-module switch;
sending exchange fabric parameters to internal ports of the multi-module switch; and
processing principal switch selection events.
2. A method for processing principal switch selection events in a fibre channel system using a multi-module fibre channel switch, comprising:
determining if exchange fabric parameters have been received by a switch module;
determining if domain identification values have been received by the switch module;
sending domain identification values to all internal ports; and
operating as a non-principal switch if the switch module is also a primary blade.
3. The method for claim 2, further comprising: determining if a F_S_TOV timer has expired if no domain identification value is received; and
operating as the principal switch if the switch module is a primary blade and the F_S-TOV timer has expired.
3. The method of claim 2, further comprising:
assigning the switch module as a non-primary blade if the domain identification value is received by the switch module and the switch module is not a primary blade.
4. A method for operating a principal switch in a fibre channel system using a multi-module switch, comprising:
sending exchange blade parameters with a local domain assigned value to plural internal ports in the switch module.
5. A method for operating a multi-module switch as a non-principal switch in a fibre channel system, comprising:
requesting local domain identification values from other modules; and
sending exchange blade parameters with local domain assigned values to internal ports.
6. The method of claim 5, further comprising:
isolating the switch module if the local domain assignment value was unsuccessful.
7. A method for domain identification value assignment for a multi-module switch in a fibre channel system, comprising:
receiving exchange blade parameters with local domain value assigned; and
sending domain identification value assigned flags to external ports.
8. The method of claim 7, further comprising:
isolating external ports if the exchange blade parameter has a rejected value for local domain assignment.
Description
    CROSS REFERENCE TO RELATED APPLICATION
  • [0001]
    This application is related to U.S. patent application entitled “METHOD AND SYSTEM FOR PRIMARY BLADE SELECTION IN A MULTI-MODULE FIBRE CHANNEL SWITCH”, Attorney Docket No. QN1009.US, Ser. No. ______, having common inventors and Assignee, filed on even date herewith, the disclosure of which is incorporated herein by reference in its' entirety.
  • BACKGROUND
  • [0002]
    1. Field of the Invention
  • [0003]
    The present invention relates to networking systems, and more particularly to systems using fibre channel fabrics for interconnecting fibre channel devices.
  • [0004]
    2. Background of the Invention
  • [0005]
    Fibre channel is a set of American National Standard Institute (ANSI) standards which provide a serial transmission protocol for storage and network protocols such as HIPPI, SCSI, IP, ATM and others. Fibre channel provides an input/output interface to meet the requirements of both channel and network users.
  • [0006]
    Fibre channel supports three different topologies: point-to-point, arbitrated loop and fibre channel fabric. The point-to-point topology attaches two devices directly. The arbitrated loop topology attaches devices in a loop. The fibre channel fabric topology attaches host systems directly to a fabric, which are then connected to multiple devices. The fibre channel fabric topology allows several media types to be interconnected.
  • [0007]
    Fibre channel is a closed system that relies on multiple ports to exchange information on attributes and characteristics to determine if the ports can operate together. If the ports can work together, they define the criteria under which they communicate.
  • [0008]
    In fibre channel, a path is established between two nodes where the path's primary task is to transport data from one point to another at high speed with low latency, performing only simple error detection in hardware. The fibre channel switch provides circuit/packet switched topology by establishing multiple simultaneous point-to-point connections.
  • [0009]
    Fibre channel fabric devices include a node port or “N_Port” that manages fabric connections. The N_port establishes a connection to a fabric element (e.g., a switch) having a fabric port or F_port. Fabric elements include the intelligence to handle routing, error detection, recovery, and similar management functions.
  • [0010]
    A fibre channel switch is a multi-port device where each port manages a simple point-to-point connection between itself and its attached system. Each port can be attached to a server, peripheral, I/O subsystem, bridge, hub, router, or even another switch. A switch receives a connection request from one port and automatically establishes a connection to another port. Multiple calls or data transfers happen concurrently through the multi-port fibre channel switch.
  • [0011]
    A fibre channel switch may use multiple modules (also referred to as “blades” or “blade”) connected by fibre channel ports. Conventionally, a multi-module switch should appear to the other devices in the fibre channel fabric as a single switch.
  • [0012]
    Fibre channel switch addressing is defined by Fibre Channel Standard FC-SW-2. Typically, a 24-bit identifier is used to uniquely identify a switch. The 24 bit address includes a 8-bit Domain Identification (“Domain_ID.”) number; 8-bit Area Identifier (Area_ID)and 8-bit Port Identifer (Port_ID), as stated in FC-SW2 Section 4.8, incorporated herein by reference in its entirety.
  • [0013]
    Domain_ID identifies a domain of one or more switches that have the same Domain_ID for all N_Ports and NL_Ports (an N_Port that can perform an Arbitrated Loop function). A domain in the fibre channel environment as defined by ANSI Standard X3.289-199X Fibre Channel-Fabric Generic Requirements (FC-FG), incorporated herein by reference in its entirety, is the highest or most significant hierarchical level in a three-level addressing scheme. If there are more than one switch in a Domain, then each switch within the domain is directly connected via an inter-switch link (“ISL”) to at least another switch in the domain.
  • [0014]
    Conventional systems pre-define a Domain_ID when a fibre channel switch is configured. Typically, a switch is assigned a Domain_ID the procedures defined in FC-SW-2. However, if a multi-module switch needs to appear as a single switch to the rest of the Fabric, the Domain_ID assignment procedure must be such that a consistent interface is available within the fabric.
  • [0015]
    Current Fiber Channel standards do not provide a mechanism to combine multiple switch modules into one switch.
  • [0016]
    Therefore, what is required is a process and system that can dynamically assign Domain_ID after a primary blade in a multi-module switch is selected.
  • SUMMARY OF THE INVENTION
  • [0017]
    In one aspect, the present invention solves the foregoing drawbacks by providing a method for entering fabric configuration in a fibre channel system for a multi-module fibre channel switch. The method includes determining if a primary blade has been selected for the multi-module switch; sending exchange fabric parameters to internal ports of the multi-module switch; and processing principal switch selection events.
  • [0018]
    In another aspect of the present invention, a method for processing principal switch selection events in a fibre channel system using a multi-module fibre channel switch is provided. The method includes determining if a switch module has received exchange fabric parameters; determining if the switch module has received domain identification values; sending domain identification values to all internal ports; and operating as a non-principal switch if the switch module is also a primary blade.
  • [0019]
    The method also includes determining if a F_S_TOV timer has expired if no domain identification value is received; and operating as the principal switch if the switch module is a primary blade and the F_S-TOV timer has expired.
  • [0020]
    In another aspect of the present invention, a method for operating a principal switch in a fibre channel system using a multi-module switch is provided. The method includes sending exchange blade parameters with a local domain assigned value to plural internal ports in the switch module.
  • [0021]
    In yet another aspect, a method for operating a multi-module switch as a non-principal switch in a fibre channel system is provided. The method includes requesting local domain identification values from other modules; and sending exchange blade parameters with local domain assigned values to internal ports. The method includes isolating the switch module if the local domain assignment value was unsuccessful.
  • [0022]
    In yet another aspect, a method for domain identification value assignment for a multi-module switch in a fibre channel system is provided. The method includes receiving exchange blade parameters with local domain value assigned; and sending domain identification value assigned flags to external ports.
  • [0023]
    The method includes isolating external ports if the exchange blade parameter has a rejected value for local domain assignment.
  • [0024]
    In one aspect of the present invention, Domain_ID may be dynamically assigned.
  • [0025]
    In another aspect of the present invention, a multi-module switch can act as a principal switch, with the primary blade performing Domain_ID assignments for the multi-module switch and for other external switches. The multi-module switch can also operate as non-principal switch, with the primary blade requesting a Domain_ID assignment on behalf of the multi-module switch and informing the other modules of the assignment.
  • [0026]
    This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiments thereof concerning the attached drawings.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [0027]
    The foregoing features and other features of the present invention will now be described with reference to a fibre channel system. In the drawings, the same components have the same reference numerals. The illustrated embodiment is intended to illustrate, but not to limit the invention. The drawings include the following Figures:
  • [0028]
    FIG. 1, as described above, shows a block diagram of a fibre channel system using a fibre channel fabric;
  • [0029]
    FIG. 2 is a block diagram showing multi-module switch;
  • [0030]
    FIG. 3 is block diagram of a switch in a multi-module switch environment that can select a primary blade, according to one aspect of the present invention;
  • [0031]
    FIG. 4 is a process flow diagram of executable process steps for selecting a primary blade in a multi-module switch environment;
  • [0032]
    FIG. 5 is a flow diagram of a executable process steps for processing exchange blade parameters for selecting a primary blade, according to one aspect of the present invention;
  • [0033]
    FIG. 6 is a block diagram showing ISLs between plural multi-module switches;
  • [0034]
    FIG. 7 is a process flow diagram of executable process steps for fabric configuration entry criteria for each blade, according to one aspect of the present invention;
  • [0035]
    FIG. 8 is a process flow diagram of executable process steps for principal switch selection, according to one aspect of the present invention;
  • [0036]
    FIG. 9 is a process flow diagram of executable process steps for primary blade and principal switch operation, according to one aspect of the present invention;
  • [0037]
    FIG. 10 is a process flow diagram of executable process steps for primary blade, and non-principal switch operation, according to one aspect of the present invention; and
  • [0038]
    FIG. 11 is a process flow diagram of executable process steps for non-primary blade operation during Domain_ID address assignment, according to one aspect of the present invention.
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • [0039]
    Definitions:
  • [0040]
    The following definitions are provided as they are typically (but not exclusively) used in the fibre channel environment, implementing the various adaptive aspects of the present invention.
      • a. “Blade”: A module in a multi-module fibre channel switch.
      • b. “Blade_ID”: A unique identifier for identifying a switch module.
      • c. “B_S_TOV Timer”: A timer to detect inactivity during primary blade selection.
      • d. “E-Port”: Expansion port
      • e. “EBP”: Exchange Blade Parameters, created by a Multi-Blade Protocol.
      • f. “EFP”: Exchange Fabric Parameters as defined by FC-SW-2.
      • g. “Fibre channel ANSI Standard”: The standard describes the physical interface, transmission and signaling protocol of a high performance serial link for support of other high level protocols associated with IPI, SCSI, IP, ATM and others.
      • h. “FC-1”: Fibre channel transmission protocol, which includes serial encoding, decoding and error control.
      • i. “FC-2”: Fibre channel signaling protocol that includes frame structure and byte sequences.
      • j. “FC-3”: Defines a set of fibre channel services that are common across plural ports of a node.
      • k. “FC-4”: Provides mapping between lower levels of fibre channel, IPI and SCSI command sets, HIPPI data framing, IP and other upper level protocols.
      • l. “Fabric”: A system which interconnects various ports attached to it and is capable of routing fibre channel frames by using destination identifiers provided in FC-2 frame headers.
      • m. “Fabric Topology” This is a typology where a device is directly attached to a fibre channel fabric that uses destination identifiers embedded in frame headers to route frames through a fibre channel fabric to a desired destination.
      • n. F_S_TOV Timer: Defined by FC-SW-2, a time constant used to ensure that fabric stability has been achieved during fabric configuration.
      • o. Multi Blade protocol: A protocol that operates on internal switch module ports to assign a primary blade and exchange blade parameters.
      • p. Port: A general reference to N. Sub.—Port or F.Sub.—Port.
      • q. “Slot Number”: A unique identifier for each blade in a multi-module switch derived from the physical location of the blade in a chasis.
  • [0058]
    The Fibre Channel Specification used to build one embodiment of the present invention includes:
  • [0059]
    FC-SW-2 standard as published by the American National Standard Institute.
  • [0060]
    To facilitate an understanding of the preferred embodiment, the general architecture and operation of a fibre channel system will be described. The specific architecture and operation of the preferred embodiment will then be described with reference to the general architecture of the fibre channel system.
  • [0061]
    FIG. 1 is a block diagram of a fibre channel system 100 implementing the methods and systems in accordance with the adaptive aspects of the present invention. System 100 includes plural devices that are interconnected. Each device includes one or more ports, classified as node ports (N_Ports), fabric ports (F_Ports), and expansion ports (E_Ports). Node ports may be located in a node device, e.g. server 103, disk array 105 and storage device 104. Fabric ports are located in fabric devices such as switch 101 and 102. Arbitrated loop 105 may be operationally coupled to switch 101 using arbitrated loop ports (FL;Ports).
  • [0062]
    The devices of FIG. 1 are operationally coupled via “links” or “paths”. A path may be established between two N_ports, e.g. between server 103 and storage 104. A packet-switched path may be established using multiple links, e.g. an N-Port in server 103 may establish a path with disk array 105 through switch 102.
  • [0063]
    Switch 101 includes an E_Port that enables a path to another switch 102. An ISL enables N_Ports to operationally couple to other N-Ports in a fabric.
  • [0064]
    FIG. 2 is a block diagram that shows plural switch modules (or blades) 102A-102F integrated into a single multi-switch module 200. Internal ports between the switch modules operate on a multi-blade protocol, while external ports operate under FC-SW-2 protocol.
  • [0065]
    FIG. 3 is a block diagram of a blade in a multi-module switch, e.g. 102A that implement the adaptive aspects of the present invention. Switch module 102A includes plural external ports (F_Ports operationally coupled to other devices, e.g. server 103; or E_Ports coupled to other switch modules) 300A through 300D; and internal ports 301A-301D that operate under the multi-blade protocol.
  • [0066]
    Switch module 102A also includes a primary blade state machine 302 that uses EBPs under the multi-blade protocol to select the primary blade for module 200.
  • [0067]
    Also included in switch module 102A is a principal switch state machine 303 that processes principal switch selection and Domain_ID assignment for the switch module.
  • [0068]
    Primary Blade Selection:
  • [0069]
    FIG. 4 shows a flow diagram of executable process steps for selecting a primary blade in a multi-module switch environment. In one aspect of the present invention EBP parameters are used to select a primary blade, and once a primary blade is selected other blades are notified of the primary blade selection. A blade with the lowest priority and slot number is selected as the primary blade. As defined above, a slot number is unique to a particular blade (or switch module, used interchangeably throughout this specification).
  • [0070]
    Turning in detail to FIG. 4, in step S400 the process starts and switch module 200 is initialized.
  • [0071]
    In step S401, retained primary blade priority and blade number is initialized to the blade's priority and blade number.
  • [0072]
    In step S402, internal ports 301A-301D are initialized.
  • [0073]
    In step S403, a B_S-TOV timer is started and thereafter, in steps S404, an EBP request is sent to all adjacent blades. In one aspect the B_S_TOV timer (not shown) is operationally coupled or integrated with state machine 302.
  • [0074]
    An example of an EBP request is provided below:
    TABLE 1
    EBP Request Payload
    Byte
    Item Size
    Command Code = hex′82′ 1
    Reserved 1
    Payload Length 2
    Reserved 3
    Primary Blade Priority 1
    Reserved 3
    Primary Blade Slot 1
    Number
    Reserved 3
    Primary Blade Assigned 1
    Local Domain_ID Status 1
    Reserved 2
    Local Domain_ID 1
    Reserved 3
    Switch Priority 1
    Design specific data N
  • [0075]
    Payload Length: This field may contain a 16-bit unsigned integer that specifies the total payload length in bytes. This value is hex′18′+size of design specific data.
  • [0076]
    Primary Blade Priority: This field specifies the priority level of a blade that an EBP transmitting blade believes is the primary blade.
  • [0077]
    Primary Blade Slot Number: This field specifies the slot number of the blade that the EBP transmitting blade believes is the primary blade. This value uniquely identifies each blade in a switch derived from the physical location of the module in a chassis.
  • [0078]
    Primary Blade Assigned: This field indicates that the primary blade role is assigned. If zero, the primary blade has not been selected. If non-zero, the primary blade has been selected. Table 2 below shows an example of primary blade values.
    TABLE 2
    Primary Blade
    Assigned Status
    value Comments
    0 Unassigned. Primary
    blade selection is
    in progress.
    1 Assigned. Primary
    blade role assigned.
  • [0079]
    Local Domain_ID Status: Indicates Domain_ID status of a blade. The primary blade is responsible for requesting a Domain_ID on behalf of all blades. When Local Domain_ID status is two, blades are permitted to transmit Domain_ID assignment (“DIA”) requests on external E_Ports. Allowable shown in Table 3.
    TABLE 3
    Local Domain_ID Status
    value Comments
    1 Predefined. Local Domain_ID was
    predefined by configuration data.
    2 Accepted. Local Domain_ID has been
    granted by principal switch.
    3 Accepted. Local Domain_ID has been
    granted by principal switch and
    fabric is in reconfiguration.
    4 Rejected. Local Domain_ID has been
    rejected by principal switch.
    5 Rejected. Local Domain_ID has been
    rejected by principal switch and
    fabric is in reconfiguration.
  • [0080]
    Local Domain_ID: This denotes a switch's local Domain_ID.
  • [0081]
    Switch Priority Value: This denotes a switch's priority as defined by FC-SW-2. In step S405, the process determines if all switch modules have received an EBP payload. If an EBP payload has been received then the EBP is processed in step S406, as shown in the process steps of FIG. 5. If a primary blade has been selected, as determined in step S407, the local blade is set as a non-primary blade in step S408. If the primary blade has not been selected, then the process moves back to step S405.
  • [0082]
    If an EBP is not received in step s405, then in step S405A, the process determines, if the B_S_TOV timer has expired. If the timer has not expired the process moves to step s405.
  • [0083]
    If the timer has expired, then in step S409, the process determines if the retained slot number is the local slot number. If not, the process moves to step s405.
  • [0084]
    If the retained slot number is the local slot number, then in step S410, the local blade is set as the primary blade.
  • [0085]
    In step S411, the primary blade sends EBPs to all internal ports and the selected blade operates as the primary blade in step S412.
  • [0086]
    FIG. 5 is a flow diagram of executable process steps that describes processing of EBPs (step S406) for selecting a primary blade, according to one aspect of the present invention.
  • [0087]
    Turning in detail to FIG. 5, in step S500, EBP's are received and the B_S_TOV timer is started.
  • [0088]
    In step S501, the EBP payload is analyzed by primary blade state machine 302, to determine whether a primary blade flag is set. If it is set, then the process moves to step S503, where the EBP priority and slot number replaces the retained priority and slot number.
  • [0089]
    If the primary blade flag is not set in step S501, then in step S502, the process determines if the EBP priority is less than the retained priority. If it is less, then the process moves to step S503.
  • [0090]
    If the EBP priority is not less than the retained priority, then in step S506, the process determines if the EBP priority is equal to the retained priority. If not, the process terminates at step S508.
  • [0091]
    If the EBP priority is equal to the retained priority, then in step S507, the process determines if the EBP slot number is less than the retained slot number. If it is less, then the process moves to step S503. If not, the process terminates at step S508.
  • [0092]
    Once the EBP priority and slot number are retained in step S503, in step S504 (similar to step S411), EBPs are sent to all internal ports with the selected primary blade and the process terminates in step S505.
  • [0093]
    Principal Switch and Domain ID Assignment:
  • [0094]
    A principal switch is selected whenever an external E_Port ISL is established.
  • [0095]
    FIG. 6 shows plural multi-module switches 200A-200D operationally coupled to each other. Each multi-module switch has a primary blade that may be selected by the process discussed above. Each switch module (blade) has its own state machine. By following the process steps described below, the switch modules will appear to the rest of the Fabric as a single switch. Non-multi-module switches use the process defined by FC-SW-2.
  • [0096]
    FIG. 7 is a process flow diagram of executable process steps for switch modules in a fabric to enter fabric configuration. In one aspect of the present invention, a primary blade is selected before the principal switch selection process is started. In a single blade switch, the only blade operates as the primary blade. A switch sends EFPs during fabric configuration and inter-blade EFP exchange occurs at the same time. A blade with external E_Port ISL can initiate principal switch selection on behalf of other blades and send EFPs. Other blades receive EFPs on internal ports, signaling the start of principal switch selection. Each blade may also operate independently during EFP exchange.
  • [0097]
    Turning in detail to FIG. 7, in step S701, a switch module (e.g. 200A) enters fabric configuration. The switch module waits in step S702 for a primary blade to be selected, as described above. After primary blade selection is complete in step S702, the process determines whether an external E_Port is initialized in step S703.
  • [0098]
    If external E_Port ISL initialization is complete in step S703, the switch module initiates principal switch selection. In step S704, an EFP is sent to external E_Ports as specified in FC-SW-2 and in step S707, EFPs are sent on all internal E_Ports to notify other switch modules that principal switch selection has started.
  • [0099]
    If external E_Ports are not initialized in step S703, then in step S705, the process determines if an EFP has been received on an internal port, before starting principal switch selection. In step S705, a switch module receiving an EFP on an internal port joins principal switch selection, and in step S706 the EFPs are processed as specified in FC-SW-2.
  • [0100]
    In step S707, EFPs are sent on all internal E_Ports to notify all other switch modules that principal switch selection has started.
  • [0101]
    In step S708 each switch module initializes principal switch selection timer F_S_TOV as specified in FC-SW-2. The process then moves to the principal switch selection process in step S709, described below with respect to FIG. 8.
  • [0102]
    FIG. 8 is a flow diagram of executable process steps for principal switch selection (step s709). The process starts when the principal switch selection entry is completed in FIG. 7. After a principal switch is selected, each switch module transitions to one of three domain address assignment processes, described below.
  • [0103]
    Turning in detail to FIG. 8, in step S801 the principal switch selection events starts. Principal switch selection events are processed in steps S802, S804 and S809 until a principal switch is selected. The events include receipt of EFPS, DIA flags and expiration of F-S-TOV timer. These events may be processed in any order.
  • [0104]
    If an EFP is received in step S802, the process moves to step S803. In step S803, the EFP is processed as specified in FC-SW-2 for principal switch selection.
  • [0105]
    If an EFP is not received, then the process determines if a set DIA flag is received in step S804, signaling the end of principal switch selection. If the DIA flag is set then the switch module does not become the principal switch and the process moves to step S805.
  • [0106]
    In step S805, the process sends DIA flag values to internal ports to notify other switch modules that principal switch selection is complete. Other switch modules in step S804 receive DIA values sent in step S805.
  • [0107]
    In step S806, the process determines if the switch module is the primary blade. If it is the primary blade then the process moves to step S807 and the switch module operates as a non-principal switch, described below with respect to FIG. 10.
  • [0108]
    In step S806, if the switch module is not the primary blade, the process moves to step S808 and the switch module operates as a non-primary blade during domain address assignment described below with respect to FIG. 11.
  • [0109]
    If the DIA flag is not set in step S804, then in step S809, the process determines if the F-S_TOV timer has expired. If F_S_TOV timer expires in step S809, the switch module may become the principal switch.
  • [0110]
    In step S810, the process determines if the switch module is the primary blade. If yes, then in step S811, the process determines if the switch module is the principal switch. The process compares the switch's worldwide name with the principal switch's worldwide name discovered in step S803. If either step S810 or S811 is false, the process resumes wait for the next event. If the switch module is the principal switch in step S811, then the process moves to step S812 and the switch module operates as the principal switch described below with respect to FIG. 9.
  • [0111]
    FIG. 9 is a process flow diagram of executable process steps for a primary blade that operates as a principal switch (step S812, FIG. 8). In addition to standard FC-SW-2 operations, the primary blade sends the switch's local Domain_ID status to non-primary blades.
  • [0112]
    Turning in detail to FIG. 9, in step S901, a primary blade operates as the principal switch.
  • [0113]
    In step S902, the primary blade assigns the local switch Domain_ID as specified in FC-SW-2, including sending DIA flags to external E_Ports and internal ports. It is noteworthy that non-primary blades at step S804 receive the DIA flags.
  • [0114]
    In step S903, an EBP with this switch's local Domain_ID and status is sent to all non-primary blades. Other non-primary blades at step S1102, as described below, also receive these EBPs.
  • [0115]
    In step S904, the switch continues to operate as the principal switch as specified in FC-SW-2.
  • [0116]
    FIG. 10 is a process flow diagram of executable process steps for a primary blade that operates as a non-principal switch. In addition to standard FC-SW-2 operations, the primary blade sends this switch's local Domain_ID and status to non-primary blades.
  • [0117]
    Turning in detail to FIG. 10, in step S1001, a primary blade operates as a non-principal switch.
  • [0118]
    In step S1002, the primary blade requests a local switch Domain_Id as specified in FC-SW-2.
  • [0119]
    In step S1003, the process verifies if the local Domain_ID request is successful, and if successful, the process moves to step S1004.
  • [0120]
    In step S1004, an EBP with the switch's local Domain_ID and status flag is sent to all non-primary blades. Other non-primary blades at step S1102 also receive these EBPs.
  • [0121]
    In step S1005, the switch continues to operate as a non-principal switch, as specified in FC-SW-2, and sends DIA information to external E_Ports and internal ports.
  • [0122]
    Returning to step S1003, if the local Domain_ID request is unsuccessful then the process moves to step S1006. In step S1006, EBPs with the switch's local Domain_ID and status flags are sent to all non-primary blades. Other non-primary blades at step S1104 receive these EBPs. Thereafter, in step S1007, external E-port ISLs are isolated per FC-SW-2.
  • [0123]
    FIG. 11 is a process flow diagram of executable process steps for a non-primary blade during Domain_ID assignment (S808). The non-primary blade waits until this switch's local Domain_ID and status flags are received from the primary blade.
  • [0124]
    Turning in detail to FIG. 11, in step S1101, a non-primary blade moves to Domain_ID assignment. The non-primary blade waits for an EBP indicating that the local switch Domain_ID is either accepted in step S1102 or rejected in steps S1104. When the local switch domain is accepted in step S1102, the switch module operates with the EBP local switch Domain_ID.
  • [0125]
    In step S1103, the switch module sends DIA information to external E-Port ISLs to notify neighboring switches as specified in FC-SW-2.
  • [0126]
    When the local switch domain is rejected in step S1104, the switch module operates with the EBP local switch Domain_ID and in step S1105, the switch module isolates external E-Ports.
  • [0127]
    In one aspect of the present invention, Domain_ID may be dynamically assigned.
  • [0128]
    In another aspect of the present invention, a multi-module switch can act as a principal switch, with the primary blade performing Domain_ID assignment for the multi-module switch and for other external switches. The multi-module switch can also operate as non-principal switch, with the primary blade requesting a Domain_ID assignment on behalf of the multi-module switch and informing the other modules of the assignment.
  • [0129]
    Although the present invention has been described with reference to specific embodiments, these embodiments are illustrative only and not limiting. Many other applications and embodiments of the present invention will be apparent in light of this disclosure and the following claims
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4081612 *14 Jul 197628 Mar 1978Hasler AgMethod for building-up of routing addresses in a digital telecommunication network
US4200929 *23 Jan 197829 Apr 1980Davidjuk Alexandr DInput device for delivery of data from digital transmitters
US4258418 *28 Dec 197824 Mar 1981International Business Machines CorporationVariable capacity data buffer system
US4268906 *22 Dec 197819 May 1981International Business Machines CorporationData processor input/output controller
US4382159 *29 May 19813 May 1983Bowditch Robert SBlow actuated microphone
US4449182 *5 Oct 198115 May 1984Digital Equipment CorporationInterface between a pair of processors, such as host and peripheral-controlling processors in data processing systems
US4803622 *7 May 19877 Feb 1989Intel CorporationProgrammable I/O sequencer for use in an I/O processor
US5090011 *21 Dec 198918 Feb 1992Hitachi, Ltd.Packet congestion control method and packet switching equipment
US5115430 *24 Sep 199019 May 1992At&T Bell LaboratoriesFair access of multi-priority traffic to distributed-queue dual-bus networks
US5212795 *10 Feb 199218 May 1993California Institute Of TechnologyProgrammable DMA controller
US5276807 *20 Jul 19904 Jan 1994Emulex CorporationBus interface synchronization circuitry for reducing time between successive data transmission in a system using an asynchronous handshaking
US5280483 *9 Aug 199118 Jan 1994Fujitsu LimitedTraffic control system for asynchronous transfer mode exchange
US5291481 *4 Oct 19911 Mar 1994At&T Bell LaboratoriesCongestion control for high speed packet networks
US5390173 *22 Oct 199214 Feb 1995Digital Equipment CorporationPacket format in hub for packet data communications system
US5594672 *20 May 199414 Jan 1997Micro Energetics CorporationPeripheral power saver
US5623492 *24 Mar 199522 Apr 1997U S West Technologies, Inc.Methods and systems for managing bandwidth resources in a fast packet switching network
US5706279 *18 Feb 19976 Jan 1998U S West Technologies, Inc.Methods and systems for managing packet flow into a fast packet switching network
US5729762 *21 Apr 199517 Mar 1998Intel CorporationInput output controller having interface logic coupled to DMA controller and plurality of address lines for carrying control information to DMA agent
US5732206 *23 Jul 199624 Mar 1998International Business Machines CorporationMethod, apparatus and program product for disruptive recovery in a data processing system
US5740467 *21 Sep 199414 Apr 1998Digital Equipment CorporationApparatus and method for controlling interrupts to a host during data transfer between the host and an adapter
US5757771 *14 Nov 199526 May 1998Yurie Systems, Inc.Queue management to serve variable and constant bit rate traffic at multiple quality of service levels in a ATM switch
US5758187 *15 Mar 199626 May 1998Adaptec, Inc.Method for enhancing performance of a RAID 1 read operation using a pair of I/O command blocks in a chain structure
US5875343 *20 Mar 199723 Feb 1999Lsi Logic CorporationEmploying request queues and completion queues between main processors and I/O processors wherein a main processor is interrupted when a certain number of completion messages are present in its completion queue
US5881296 *2 Oct 19969 Mar 1999Intel CorporationMethod for improved interrupt processing in a computer system
US5892969 *15 Mar 19966 Apr 1999Adaptec, Inc.Method for concurrently executing a configured string of concurrent I/O command blocks within a chain to perform a raid 5 I/O operation
US5905905 *5 Aug 199718 May 1999Adaptec, Inc.System for copying IOBS from FIFO into I/O adapter, writing data completed IOB, and invalidating completed IOB in FIFO for reuse of FIFO
US6011779 *30 Dec 19964 Jan 2000Hyundai Electronics AmericaATM switch queuing system
US6026092 *31 Dec 199615 Feb 2000Northern Telecom LimitedHigh performance fault tolerant switching system for multimedia satellite and terrestrial communications networks
US6031842 *26 Nov 199729 Feb 2000Mcdata CorporationLow latency shared memory switch architecture
US6046979 *4 May 19984 Apr 2000Cabletron Systems, Inc.Method and apparatus for controlling the flow of variable-length packets through a multiport switch
US6049802 *27 Jun 199411 Apr 2000Lockheed Martin CorporationSystem and method for generating a linked list in a computer memory
US6055603 *18 Sep 199725 Apr 2000Emc CorporationMethod and apparatus for performing pre-request operations in a cached disk array storage system
US6055618 *31 Oct 199525 Apr 2000Cray Research, Inc.Virtual maintenance network in multiprocessing system having a non-flow controlled virtual maintenance channel
US6061360 *24 Feb 19999 May 2000Seagate Technology, Inc.Method and apparatus for preserving loop fairness with dynamic half-duplex
US6185203 *18 Feb 19976 Feb 2001Vixel CorporationFibre channel switching fabric
US6185620 *3 Apr 19986 Feb 2001Lsi Logic CorporationSingle chip protocol engine and data formatter apparatus for off chip host memory to local memory transfer and conversion
US6201787 *15 Sep 199913 Mar 2001Emulex CorporationAutomatic loop segment failure isolation
US6209089 *12 Aug 199827 Mar 2001Microsoft CorporationCorrecting for changed client machine hardware using a server-based operating system
US6229822 *13 Sep 19998 May 2001Newbridge Networks CorporationCommunications system for receiving and transmitting data cells
US6230276 *1 Feb 19998 May 2001Douglas T HaydenEnergy conserving measurement system under software control and method for battery powered products
US6233244 *18 Dec 199715 May 2001Advanced Micro Devices, Inc.Method and apparatus for reclaiming buffers
US6335935 *30 Jun 19991 Jan 2002Broadcom CorporationNetwork switching architecture with fast filtering processor
US6343324 *13 Sep 199929 Jan 2002International Business Machines CorporationMethod and system for controlling access share storage devices in a network environment by configuring host-to-volume mapping data structures in the controller memory for granting and denying access to the devices
US6504846 *21 May 19997 Jan 2003Advanced Micro Devices, Inc.Method and apparatus for reclaiming buffers using a single buffer bit
US6522656 *29 Sep 199818 Feb 20033Com CorporationDistributed processing ethernet switch with adaptive cut-through switching
US6532212 *25 Sep 200111 Mar 2003Mcdata CorporationTrunking inter-switch links
US6546010 *4 Feb 19998 Apr 2003Advanced Micro Devices, Inc.Bandwidth efficiency in cascaded scheme
US6684209 *27 Apr 200027 Jan 2004Hitachi, Ltd.Security method and system for storage subsystem
US6697359 *2 Jul 199924 Feb 2004Ancor Communications, Inc.High performance switch fabric element and switch systems
US6697368 *15 May 200124 Feb 2004Foundry Networks, Inc.High-performance network switch
US6718497 *21 Apr 20006 Apr 2004Apple Computer, Inc.Method and apparatus for generating jitter test patterns on a high performance serial bus
US6721799 *30 Dec 199913 Apr 2004Koninklijke Philips Electronics N.V.Method for automatically transmitting an acknowledge frame in canopen and other can application layer protocols and a can microcontroller that implements this method
US6725388 *13 Jun 200020 Apr 2004Intel CorporationMethod and system for performing link synchronization between two clock domains by inserting command signals into a data stream transmitted between the two clock domains
US6859435 *24 Jul 200022 Feb 2005Lucent Technologies Inc.Prevention of deadlocks and livelocks in lossless, backpressured packet networks
US6865157 *26 May 20008 Mar 2005Emc CorporationFault tolerant shared system resource with communications passthrough providing high availability communications
US6983342 *8 Oct 20023 Jan 2006Lsi Logic CorporationHigh speed OC-768 configurable link layer chip
US6987768 *19 Apr 200017 Jan 2006Fujitsu LimitedPacket transferring apparatus
US6988130 *6 May 200217 Jan 2006Emc CorporationVirtual ports for partitioning of data storage
US6988149 *26 Feb 200217 Jan 2006Lsi Logic CorporationIntegrated target masking
US7000025 *7 May 200214 Feb 2006Adaptec, Inc.Methods for congestion mitigation in infiniband
US7002926 *30 Nov 200021 Feb 2006Western Digital Ventures, Inc.Isochronous switched fabric network
US7010607 *14 Sep 20007 Mar 2006Hewlett-Packard Development Company, L.P.Method for training a communication link between ports to correct for errors
US7024410 *15 Dec 20034 Apr 2006Hitachi, Ltd.Security method and system for storage subsystem
US7171050 *11 Feb 200330 Jan 2007Samsung Electronics Co., Ltd.System on chip processor for multimedia devices
US7185062 *18 Jan 200227 Feb 2007Emc CorporationSwitch-based storage services
US7188364 *25 Jan 20026 Mar 2007Cranite Systems, Inc.Personal virtual bridged local area networks
US7190667 *26 Apr 200113 Mar 2007Intel CorporationLink level packet flow control mechanism
US7194538 *17 Jun 200220 Mar 2007Veritas Operating CorporationStorage area network (SAN) management system for discovering SAN components using a SAN management server
US7200108 *17 May 20023 Apr 2007International Business Machines CorporationMethod and apparatus for recovery from faults in a loop network
US7315511 *26 Mar 20021 Jan 2008Fujitsu LimitedTransmitter, SONET/SDH transmitter, and transmission system
US7352740 *29 Apr 20031 Apr 2008Brocade Communciations Systems, Inc.Extent-based fibre channel zoning in hardware
US20030002503 *15 Jun 20012 Jan 2003Brewer Lani WilliamSwitch assisted frame aliasing for storage virtualization
US20030021239 *13 May 200230 Jan 2003Mullendore Rodney N.Method and apparatus for scheduling packet flow on a fibre channel arbitrated loop
US20030026267 *5 Jun 20026 Feb 2003Oberman Stuart F.Virtual channels in a network switch
US20030026287 *31 Jul 20026 Feb 2003Mullendore Rodney N.Method and system for managing time division multiplexing (TDM) timeslots in a network switch
US20030035433 *16 Aug 200120 Feb 2003International Business Machines CorporationApparatus and method for virtualizing a queue pair space to minimize time-wait impacts
US20030046396 *5 Apr 20026 Mar 2003Richter Roger K.Systems and methods for managing resource utilization in information management environments
US20030056000 *24 Jul 200220 Mar 2003Nishan Systems, Inc.Transfer ready frame reordering
US20030056032 *9 Jun 199920 Mar 2003Charles MicalizziMethod and apparatus for automatically transferring i/o blocks between a host system and a host adapter
US20030072316 *20 May 199917 Apr 2003Autumn Jane NiuApparatus and method in a network switch port for transferring data between buffer memory and transmit and receive state machines according to a prescribed interface protocol
US20030076788 *19 Oct 200124 Apr 2003Sun Microsystems, Inc.Method, system, and program for discovering devices communicating through a switch
US20030079019 *18 Jan 200224 Apr 2003Lolayekar Santosh C.Enforcing quality of service in a storage network
US20040013088 *19 Jul 200222 Jan 2004International Business Machines CorporationLong distance repeater for digital information
US20040015638 *22 Jul 200222 Jan 2004Forbes Bryn B.Scalable modular server system
US20040054776 *12 Sep 200318 Mar 2004Finisar CorporationNetwork expert analysis process
US20040054866 *5 Sep 200318 Mar 2004Blumenau Steven M.Mapping of hosts to logical storage units and data storage ports in a data processing system
US20040057389 *12 Sep 200325 Mar 2004Finisar CorporationNetwork analysis scalable analysis tool for multiple protocols
US20040081186 *1 Jul 200329 Apr 2004Vixel CorporationMethods and apparatus for switching Fibre Channel Arbitrated Loop devices
US20040081196 *29 Oct 200229 Apr 2004Elliott Stephen J.Protocol independent hub
US20040081394 *31 Jan 200129 Apr 2004Giora BiranProviding control information to a management processor of a communications switch
US20050023656 *8 Aug 20033 Feb 2005Leedy Glenn J.Vertical system integration
US20050036485 *11 Aug 200317 Feb 2005Eilers Fritz R.Network having switchover with no data loss
US20050036499 *26 Jun 200317 Feb 2005Andiamo Systems, Inc., A Delaware CorporationFibre Channel Switch that enables end devices in different fabrics to communicate with one another while retaining their unique Fibre Channel Domain_IDs
US20050036763 *13 Sep 200417 Feb 2005Motoki KatoMethod of processing multiplexed program data using entry points and time units
US20050047334 *21 Jun 20043 Mar 2005Paul Harry V.Fibre channel switch
US20050058148 *29 Mar 200417 Mar 2005Broadcom CorporationElasticity buffer for streaming data
US20060013248 *18 Mar 200519 Jan 2006Hamayun MujeebSwitching device interfaces
US20060034192 *13 Jul 200516 Feb 2006Broadcom CorporationApparatus and system for coupling and decoupling initiator devices to a network using an arbitrated loop without disrupting the network
US20060034302 *26 May 200516 Feb 2006David PetersonInter-fabric routing
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US8811227 *6 Jul 201119 Aug 2014Cisco Technology, Inc.Merging a stand-alone switch to a fibre channel network
US8830871 *15 Feb 20129 Sep 2014Cisco Technology, Inc.Persistent principal switch for fibre channel fabric
US20130010638 *6 Jul 201110 Jan 2013Cisco Technology, Inc.Merging a Stand-Alone Switch to a Fibre Channel Network
US20130208625 *15 Feb 201215 Aug 2013Cisco Technology, Inc.Persistent Principal Switch for Fibre Channel Fabric
Classifications
U.S. Classification370/360
International ClassificationH04L12/56, H04L12/50
Cooperative ClassificationH04L49/10, H04L49/357, H04L49/65
European ClassificationH04L49/35H2, H04L49/10