Patent Publication Number: US-11665083-B2

Title: Extension to software defined networking to manage storage area networks

Description:
STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR 
     The following disclosures are submitted under 35 U.S.C. 102(b)(1)(A): DISCLOSURES: An Investigation and Design of Software Defined Networking Applied to Storage Area Network Connectivity, by Gary Allen Fisher, Sr., May 2020, 339 pages. 
     BACKGROUND 
     The present invention generally relates to computer systems, and more specifically, to computer-implemented methods, computer systems, and computer program products configured and arranged to provide an extension to software defined networking to manage storage area networks. 
     A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block-level data storage. At its simplest, a SAN is a dedicated network for data storage. A SAN is a combination of hardware and software. SANs are primarily used to access storage devices, such as disk arrays and tape libraries from servers so that the devices appear to the operating system as direct-attached storage. A SAN typically is a network dedicated for Input/Output (I/O) operations with interconnections of any combination of servers, storage devices, and SAN switches, not accessible through the local area network (LAN). Although a SAN provides only block-level access, file systems built on top of SANs do provide file-level access and are known as shared-disk file systems. SANs are sometimes referred to as the network behind the servers and historically developed out of a centralized data storage model, but with its own data network. In addition to storing data, SANs allow for the automatic backup of data and the monitoring of the storage as well as the backup process. 
     SUMMARY 
     Embodiments of the present invention are directed to extensions to software defined networking (SDN) to manage storage area networks. A non-limiting example computer-implemented method includes receiving, by a switch configured with and managed by a SDN architecture, at least one table. The at least one table configured for use in the SDN architecture and including routing information. The method includes routing, by the switch, traffic over a storage area network (SAN) using the routing information in the at least one table. 
     Other embodiments of the present invention implement features of the above-described method in computer systems and computer program products. 
     Additional technical features and benefits are realized through the techniques of the present invention. Embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed subject matter. For a better understanding, refer to the detailed description and to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The specifics of the exclusive rights described herein are particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the embodiments of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG.  1    depicts a block diagram of an example computer system for use in conjunction with one or more embodiments of the present invention; 
         FIG.  2    depicts a block diagram of a system for a storage area network (SAN) in accordance with one or more embodiments of the present invention; 
         FIG.  3 A  depicts Transmission Control Protocol (TCP) TCP/Internet Protocol (IP) fields examined in match tables in accordance with one or more embodiments of the present invention; 
         FIG.  3 B  depicts SAN fields examined in match tables in accordance with one or more embodiments of the present invention; 
         FIG.  4    depicts a block diagram of switch processing in accordance with one or more embodiments of the present invention; 
         FIG.  5    depicts a block diagram of switch processing in accordance with one or more embodiments of the present invention; 
         FIG.  6    depicts a block diagram of a match header in accordance with one or more embodiments of the present invention; 
         FIG.  7    depicts a block diagram of an extensible match field format in accordance with one or more embodiments of the present invention; 
         FIG.  8    depicts a block diagram of an extensible match field for a destination address in accordance with one or more embodiments of the present invention; 
         FIG.  9    depicts a block diagram of an extensible match field for a destination address subnet in accordance with one or more embodiments of the present invention; 
         FIG.  10    depicts a block diagram of an extensible match field for a destination port in accordance with one or more embodiments of the present invention; 
         FIG.  11    depicts a block diagram of an extensible match field for a destination address and destination port in accordance with one or more embodiments of the present invention; 
         FIG.  12    depicts a block diagram of extensible match type experimenter fields for SAN objects in accordance with one or more embodiments of the present invention; 
         FIG.  13    depicts a block diagram of extensible match type experimenter fields for SAN world-wide names in accordance with one or more embodiments of the present invention; 
         FIG.  14    depicts a block diagram of extensible match type experimenter fields for SAN domain identification in accordance with one or more embodiments of the present invention; 
         FIG.  15    depicts a block diagram of extensible match type experimenter fields for SAN port identification in accordance with one or more embodiments of the present invention; 
         FIG.  16    depicts a block diagram of extensible match type experimenter fields for SAN arbitrated loop address in accordance with one or more embodiments of the present invention; 
         FIG.  17    depicts a block diagram of extensible match type experimenter fields for SAN port number in accordance with one or more embodiments of the present invention; 
         FIG.  18    depicts a block diagram of extensible match type experimenter fields for SAN exchange identifier in accordance with one or more embodiments of the present invention; 
         FIG.  19 A  depicts a block diagram of extensible match type experimenter fields for virtual SAN identification, fabric identification, and/or virtual identification in accordance with one or more embodiments of the present invention; 
         FIG.  19 B  depicts the block diagram of the extensible match type experimenter fields for virtual SAN identification, fabric identification, and/or virtual identification, as a continuation of  FIG.  19 A , in accordance with one or more embodiments of the present invention; 
         FIG.  20    depicts a block diagram of extensible match type experimenter fields for SAN domain identification and SAN port address identification in accordance with one or more embodiments of the present invention; 
         FIG.  21    depicts a block diagram of extensible match type experimenter fields for SAN domain identification and SAN arbitrated loop address in accordance with one or more embodiments of the present invention; 
         FIG.  22    depicts a block diagram of extensible match type experimenter fields for SAN domain identification, SAN port address identification, and SAN arbitrated loop address in accordance with one or more embodiments of the present invention; 
         FIG.  23    depicts a block diagram of extensible match type experimenter fields for SAN virtual identification, SAN domain identification, and SAN port address identification in accordance with one or more embodiments of the present invention; 
         FIG.  24    depicts a block diagram of extensible match type experimenter fields for SAN virtual identification, SAN domain identification, SAN port address identification, and SAN arbitrated loop address in accordance with one or more embodiments of the present invention; 
         FIG.  25    depicts a block diagram of an SDN-managed SAN switch with domain identification and port address identification to port in accordance with one or more embodiments of the present invention; 
         FIG.  26    depicts example commands to send SAN traffic for domain identification and port address identification to a port in  FIG.  25    in accordance with one or more embodiments of the present invention; 
         FIG.  27    depicts a block diagram of an SDN-managed SAN switch with world-wide name to port in accordance with one or more embodiments of the present invention; 
         FIG.  28    depicts example commands to send SAN traffic for a world-wide name to port in  FIG.  27    in accordance with one or more embodiments of the present invention; 
         FIG.  29    depicts a block diagram of an SDN-managed SAN switch to implement zoning by world-wide name in accordance with one or more embodiments of the present invention; 
         FIG.  30    depicts example commands to implement SAN zoning using world-wide names in  FIG.  29    in accordance with one or more embodiments of the present invention; 
         FIG.  31    depicts a block diagram of an SDN-managed SAN switch to implement zoning by domain name identification and port address identification in accordance with one or more embodiments of the present invention; 
         FIG.  32    depicts example commands to implement zoning by domain name identification and port address identification in  FIG.  31    in accordance with one or more embodiments of the present invention; 
         FIG.  33 A  depicts a block diagram of an SDN-managed SAN switch to implement inter-switch link selection in accordance with one or more embodiments of the present invention; 
         FIG.  33 B  depicts the block diagram of the SDN-managed SAN switch to implement inter-switch link selection, as a continuation of  FIG.  33 A , in accordance with one or more embodiments of the present invention; 
         FIG.  33 C  depicts the block diagram of the SDN-managed SAN switch to implement inter-switch link selection, as a continuation of  FIGS.  33 A and  33 B , in accordance with one or more embodiments of the present invention; 
         FIG.  34    depicts example commands to implement inter-switch link routing in  FIGS.  33 A,  33 B, and  33 C  in accordance with one or more embodiments of the present invention; 
         FIG.  35 A  depicts a block diagram of an SDN-managed SAN switch to implement fiber channel over Internet protocol tunnel selection in accordance with one or more embodiments of the present invention; 
         FIG.  35 B  depicts the block diagram of the SDN-managed SAN switch to implement fiber channel over Internet protocol tunnel selection, as a continuation of  FIG.  35 A , in accordance with one or more embodiments of the present invention; 
         FIG.  35 C  depicts the block diagram of the SDN-managed SAN switch to implement fiber channel over Internet protocol tunnel selection, as a continuation of  FIGS.  35 A and  35 B , in accordance with one or more embodiments of the present invention; 
         FIG.  36    depicts example commands to implement fiber channel over Internet protocol routing in  FIGS.  35 A,  35 B, and  35 C  in accordance with one or more embodiments of the present invention; 
         FIG.  37 A  depicts a block diagram of an SDN-managed SAN switch to implement fiber channel over Internet protocol tunnel for Internet protocol extension communication in accordance with one or more embodiments of the present invention; 
         FIG.  37 B  depicts the block diagram of the SDN-managed SAN switch to implement fiber channel over Internet protocol tunnel for Internet protocol extension communication, as a continuation of  FIG.  37 A , in accordance with one or more embodiments of the present invention; 
         FIG.  38    depicts example commands to set up a SAN fiber channel over Internet protocol tunnel/Internet protocol extension tunnel in  FIGS.  37 A and  37 B  in accordance with one or more embodiments of the present invention; 
         FIG.  39    depicts example commands to set up the network routes for fiber channel over Internet protocol tunnel/Internet protocol extension used by a switch/router in  FIGS.  37 A and  37 B  in accordance with one or more embodiments of the present invention; 
         FIG.  40    is a flowchart of a computer-implemented process for using an extension to match tables in SDN to manage SANs in accordance with one or more embodiments of the present invention; 
         FIG.  41    depicts a cloud computing environment according to one or more embodiments of the present invention; and 
         FIG.  42    depicts abstraction model layers according to one or more embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     One or more embodiments of the present invention provide computer-implemented methods, computer systems, and computer program products for generating and using extensions to software defined networking (SDN) to manage storage area networks (SANs). An SDN switch is managed by and operates using SDN and/or SDN architecture. An SDN switch that has SAN ports with or without LAN ports managed by SDN may be referred to as an SDN SAN switch, an SDN-managed SAN, a SAN with SDN architecture, etc. According to one or more embodiments, an SDN controller directs SDN switches to generate SDN match tables having extensions fields and/or experimenter fields, which are utilized to insert routing information that can be read/parsed by the SDN SAN. The SDN match tables are in an OpenFlow version 1.2 (v1.2) format and have an SDN architecture. The SDN SAN switch is configured to read incoming traffic including incoming frames having standard Transmission Control Protocol (TCP) TCP/Internet Protocol (IP) and/or standard Fibre Channel architecture and use the SDN match table to route the traffic through the appropriate SAN port of the SDN SAN switch over the SAN. Furthermore, one or more embodiments describe how to add SDN format constructs in SDN match tables to define SAN objects for use by SDN SAN switch in a storage area network. 
     Large enterprise data centers have many servers, storage, and network devices which are connected to each other to build versatile computing systems. Generally, at this time the Local Area Network (LAN) enables users and other servers to contact servers and is based on Ethernet, Internet Protocol (IP) and Transmission Control Protocol (TCP) and related standard protocols (e.g., UDP, ICMP). A SAN enables servers to contact data storage devices (storage) to access stored data, and/or enables storage to contact other storage for data replication. Both are based on copper or fiber for physical connections, with wireless increasingly used for LANs but not yet sufficiently capacious for most SAN requirements. 
     Large enterprises often have multiple data centers for resiliency against hardware failures, power outages, and natural disasters. The data in one data center can be replicated in the other data center(s) through various techniques. For example, Parallel Sysplex® from IBM® can make the data centers appear as one unit, where the applications can run in either data center and the data can reside in either data center, so any hardware or system failure does not affect the application and data availability. GDPS® from IBM automates the transition of the primary location of processing or data between sites in response to failures or business priorities, and which provides extremely high availability and performance. 
     Software Defined Networking (SDN) has been defined and refined to improve the speed and flexibility in configuring network Open System Interconnection (OSI) Layer 2 switches (for Ethernet) and OSI Layer 3 routers (for Internet Protocol, or IP) as part of its five goals: Plane separation, Simplified device, Centralized control, Network automation and virtualization, and Openness. 
     Storage Area Networks (SANs) use either the Fibre Channel Protocol (FCP) or FICON® from IBM. Although there have been several FCP switch vendors in the past, there are now only two. While the technology is standardized, the implementation by each vendor is proprietary and no longer inter-operable, is expensive, and is complex to configure and manage, thereby requiring specialized skills and personnel. 
     LANs and SANs are similar in many ways and often connect to the same servers that perform both input/output (I/O) and network tasks. Also, when data centers are separated by a significant distance (typically greater than 10 kilometers), SAN traffic can be encapsulated on the LAN using Fibre Channel over IP (FCIP), so the LAN is carrying both traditional network and I/O traffic. One vendor, Brocade, has implemented IP Extension (IPEX), where certain LAN traffic is carried on the FCIP network which is already on a LAN, in order to consolidate management tasks for communications that are functionally similar but carried on both LAN and SAN. FCIP and IPEX implementation further requires specialists in both SAN, LAN, and WAN. 
     Data Center Bridging (DCB) and Converged Enhanced Ethernet (CEE) attempted to merge LAN and SAN on a common infrastructure. NAS (network addressable storage) and iSCSI (IP-based Small Computer System Interface) discard the SAN altogether. Even with these efforts, however, LANs and SANs require different tools and skills for conceptually similar tasks. 
     SDN is not only used to control network routers at Layer 3 and switches at Layer 2 but has been extended to control physical switches and Dense Wavelength Division Multiplexors (DWDMs) at OSI Layer 1. Software Defined Networking does not manage the Storage Area Network (SAN) switches. FCIP, IPEX, and NVMEoFC (Non-Volatile Memory extended traffic over Fibre Channel) are attempting to blend the paths of network and storage, but there is not an orchestrated controlling function for this combined mesh of connectivity. One or more embodiments of the invention provide configurations of software defined networking to manage FC ports on SDN switches, thereby managing the SAN through SDN. 
     As discussed herein, one or more embodiments describe how SDN can be extended to manage SANs. There are many efficiencies with reduced and combined management techniques of similar and inter-leaved infrastructures. SDN can be applied to SANs not just for a single data center, but for other forms of inter-system communication used when connecting remote data centers according to one or more embodiments. Also, with SDN, different routing techniques can be implemented, such as those found in social and financial networks, that provide improved inter-data-center connectivity when satisfying the different requirements of SANs and LANs. Combining SAN and LAN with SDN according to one or more embodiments integrates a variety of techniques rather than have them manage similar problems separately. Accordingly, a single, common infrastructure management plane encompasses LAN, SAN, WAN (Wide Area Network), and L1 devices, which redundantly share and intertwine much of the same connectivity infrastructure, as provided in accordance with one or more embodiments. According to the improved methods discussed in one or more embodiments, a user would not need to know of the layers or architectures of the intervening connectivity devices. Rather, all devices use the same control interface (e.g., SDN). Connectivity between devices that spans multiple types of controlled devices at different layers (e.g., storage, FC, FCIP, and L3 routing) is orchestrated from a single control point that integrated all the changes, according to one or more embodiments. 
     Turning now to  FIG.  1   , a computer system  100  is generally shown in accordance with one or more embodiments of the invention. The computer system  100  can be an electronic, computer framework comprising and/or employing any number and combination of computing devices and networks utilizing various communication technologies, as described herein. The computer system  100  can be easily scalable, extensible, and modular, with the ability to change to different services or reconfigure some features independently of others. The computer system  100  can be, for example, a server, desktop computer, laptop computer, tablet computer, smartphone, SDN controller, and/or SDN switch. In some examples, computer system  100  can be a cloud computing node. Computer system  100  can be described in the general context of computer system executable instructions, such as program modules, being executed by a computer system. Generally, program modules can include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system  100  can be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules can be located in both local and remote computer system storage media including memory storage devices. 
     As shown in  FIG.  1   , the computer system  100  has one or more central processing units (CPU(s))  101   a ,  101   b ,  101   c , etc., (collectively or generically referred to as processor(s)  101 ). The processors  101  can be a single-core processor, multi-core processor, computing cluster, ASIC (Application Specific Integrated Circuit) or any number of other configurations. The processors  101 , also referred to as processing circuits, are coupled via a system bus  102  to a system memory  103  and various other components. The system memory  103  can include a read only memory (ROM)  104  and a random access memory (RAM)  105 . The ROM  104  is coupled to the system bus  102  and can include a basic input/output system (BIOS) or its successors like Unified Extensible Firmware Interface (UEFI), which controls certain basic functions of the computer system  100 . The RAM is read-write memory coupled to the system bus  102  for use by the processors  101 . The system memory  103  provides temporary memory space for operations of said instructions during operation. The system memory  103  can include random access memory (RAM), read only memory, flash memory, or any other suitable memory systems. 
     The computer system  100  comprises input/output (I/O) adapters such as input/output (I/O) adapters  106   a ,  106   b ,  106   z  and a communications adapter  107  coupled to the system bus  102 . The I/O adapters  106   a ,  106   b ,  106   z  can be a small computer system interface (SCSI) adapter or Fibre Channel (FC) adapter that communicates with the I/O adapter of a hard disk  108  and/or any other component. The I/O adapter  106   a  and the hard disk  108  are collectively referred to herein as a mass storage  110 . The I/O adapters  106   b ,  106   z  can be directly attached to an I/O adapter and/or attached to a Storage Area Network (SAN) by connecting to a Fibre Channel (FC) port of a SAN switch (e.g., one or more of ports  260  of SDN SAN switch  230  depicted in  FIG.  2   ). 
     Software  111  for execution on the computer system  100  can be stored in the mass storage  110 . The mass storage  110  is an example of a tangible storage medium readable by the processors  101 , where the software  111  is stored as instructions for execution by the processors  101  to cause the computer system  100  to operate, such as is described herein below with respect to the various Figures. Examples of computer program product and the execution of such instruction is discussed herein in more detail. The communications adapter  107  interconnects the system bus  102  with a network  112 , which can be an outside network, enabling the computer system  100  to communicate with other such systems. In one embodiment, a portion of the system memory  103  and the mass storage  110  collectively store an operating system, which can be any appropriate operating system to coordinate the functions of the various components shown in  FIG.  1   . 
     Additional input/output devices are shown as connected to the system bus  102  via a display adapter  115  and an interface adapter  116 . In one embodiment, the adapters  106 ,  107 ,  115 , and  116  can be connected to one or more I/O buses that are connected to the system bus  102  via an intermediate bus bridge (not shown). A display  119  (e.g., a screen or a display monitor) is connected to the system bus  102  by the display adapter  115 , which can include a graphics controller to improve the performance of graphics intensive applications and a video controller. A keyboard  121 , a mouse  122 , a speaker  123 , etc., can be interconnected to the system bus  102  via the interface adapter  116 , which can include, for example, a Super I/O chip integrating multiple device adapters into a single integrated circuit. Suitable I/O buses for connecting peripheral devices such as hard disk controllers, network adapters, and graphics adapters typically include common protocols, such as the Peripheral Component Interconnect (PCI) and the Peripheral Component Interconnect Express (PCIe). Thus, as configured in  FIG.  1   , the computer system  100  includes processing capability in the form of the processors  101 , and, storage capability including the system memory  103  and the mass storage  110 , input means such as the keyboard  121  and the mouse  122 , and output capability including the speaker  123  and the display  119 . 
     In some embodiments, the communications adapter  107  can transmit data using any suitable interface or protocol, such as the internet small computer system interface, among others. The network  112  can be a cellular network, a radio network, a wide area network (WAN), a local area network (LAN), or the Internet, among others. An external computing device can connect to the computer system  100  through the network  112 . In some examples, an external computing device can be an external webserver or a cloud computing node. 
     It is to be understood that the block diagram of  FIG.  1    is not intended to indicate that the computer system  100  is to include all of the components shown in  FIG.  1   . Rather, the computer system  100  can include any appropriate fewer or additional components not illustrated in  FIG.  1    (e.g., additional memory components, embedded controllers, modules, additional network interfaces, etc.). Further, the embodiments described herein with respect to computer system  100  can be implemented with any appropriate logic, wherein the logic, as referred to herein, can include any suitable hardware (e.g., a processor, an embedded controller, or an application specific integrated circuit, among others), software (e.g., an application, among others), firmware, or any suitable combination of hardware, software, and firmware, in various embodiments. 
       FIG.  2    is a high-level schematic diagram of a storage area network (SAN)  200  in accordance with one or more embodiments of the present invention. SAN  200  includes a plurality of endpoint devices  210  that are each connected to one or more network devices, such as SAN switches  230 . As discussed herein, SAN switches  230  are managed by SDN and may be referred to as an SDN SAN switch, an SDN-managed SAN, a SAN with SDN architecture, etc. Additionally, the SAN switches  230  can be representative of an SDN switch having been modified to process SAN traffic over SAN ports as discussed herein according to one or more embodiments. Moreover, according to one or more embodiments of the invention, SAN switches  230  can process both SAN traffic over SAN ports and TC/IP (i.e., LAN) traffic over LAN ports. SAN switches  230  include memory circuitry and processing circuitry (e.g. including monitoring circuitry and limiting circuitry). The network topology of SAN  200  may be a switched fabric using SAN switches  230 . In one or more embodiments, a particular SAN switch  230  that is a switch may be set to switch mode or N-port ID virtualization (NPIV) mode. In one or more embodiments, at least one of the endpoint devices  210  in SAN  200  is configured as an SDN controller. In one or more embodiments, the SDN controller as endpoint device  210  includes functions of and/or is embodied in a computer system, such as computer system  100  shown in  FIG.  1   . SDN controller can include software applications  220  implemented, for example, as software  111  executed on one or more processors  101 , as discussed in  FIG.  1   . Using, for example, software applications  220 , the SDN controller as one or more as endpoint devices  210  is configured to generate match tables, which are SDN match tables with modified experimenter fields of the extension fields to thereby include new routing information useable for routing in SAN  200  according to one or more embodiments. The software applications  220  of SDN controller downloads and/or sends the match tables to SAN switches  230  along with updates to the match tables. One or more match tables can be stored in memory  206  and updated by software applications  220  of SDN controller. Once received, SAN switches  230  process the modified match tables according to one or more embodiments. SAN switches  230  can include software applications  204  implemented, for example, as software  111  executed on one or more processors  101 , as discussed in  FIG.  1   . Software applications  204  of SAN switches  230  are configured to process incoming traffic (e.g., frames, packets, etc.) received from endpoint device  210  according to (new) routing information in the match table and send the traffic to another endpoint device  210  in SAN  200 , in accordance with one or more embodiments. SAN switches  230  may include managing circuitry  208  in which managing circuitry  208  is configured and arranged to include forwarding circuitry, data plane circuitry, etc. Further, any of the endpoint devices  210  and SAN switches  230  can be implemented using any of the functions and hardware and software components described in computer system  100 . Examples of endpoint devices  210  which are not the SDN controller may include mail servers, applications servers, database servers, tape storages, optical storages, hard disk drives, solid state drives, other switches some of which may connect to other endpoint devices, etc. In some cases, SANs  200  are used to efficiently attach many servers running applications that need access to the stored data on many storage devices. A SAN switch (also called a FICON Director) significantly reduces the number of connections. 
     Although only one SAN switch  230  is illustrated for simplicity, it should be understood that there are numerous SAN switches  230  connected to each other and connected to various endpoint devices  210  in many configurations, as understood by one of ordinary skilled in the art. In one or more embodiments, each of the SAN switches  230  includes a plurality of ports  260  that connect the SAN switches  230  to various endpoint devices  210  via links. Ports  260  can include a variety of ports including FC ports, LAN ports, along with any combination of the ports discussed herein. In addition, each endpoint device  210  includes one or more ports that connect the end devices to one or more SAN switches  230  and/or to other endpoint devices  210 . In one or more embodiments, each link can have at least two ports that are connected to the link. The ports of endpoint devices  210  can be referred to as channel ports and/or host bus adapter ports while the ports of SAN switches  230  are referred to as switch ports. 
     In one or more embodiments, the SAN switches  230  support the Fibre Channel (FC) and/or Fibre channel over Ethernet (FCoE) Protocols. For example, a particular fixed port network device may support the FC protocol and/or the FCoE protocol. As another example, if a particular SAN switch  230  includes a plurality of line cards, at least some of which may support the FC protocol and/or at least some of which may support the FCoE protocol. It is noted that a particular port  260  on a particular SAN switch  230  may support the FC protocol or the FCoE protocol by default and/or as configured (e.g., if the particular port is a universal port). Optionally, SAN switches  230  support one or more other protocols such as simple network management protocol (SNMP) for collecting information, e.g., for output on the management device implemented as endpoint device  210 . 
     For explanation purposes and ease of understanding, section headings and/or titles are provided below. The section headings and/or titles are not meant to be limiting. 
     I. Software Defined Networking 
     Software Defined Networking (SDN) virtualizes existing Internet Protocol (IP) networks, allows flexible and rapid response to a variety of requirements, allows network engineers to simplify, automate network management, use open protocols, reduce cost, and innovate. For explanation purposes and not limitation, examples and illustrations may use OpenFlow® software. OpenFlow is a protocol that provides a simple method for orchestration of network devices in a non-proprietary method. Initially intended to allow networking researchers to try different network management schemes without the extensive delay and effort of designing and implementing specialized hardware, it became the precursor to what is now called Software Defined Networking. OpenFlow is governed by the Optical Internetworking Forum (OIF), a consortium to facilitate interoperable networking solutions. 
     The OpenFlow specification has goals of: Plane separation, Simplified device, Centralized control, Network automation and virtualization, and Openness. In the forwarding plane versus the control plane, a network device is responsible for sending a message coming from an input port to the desired output port, a process called forwarding. Forwarding tables, routing tables, address resolution protocol (ARP) caches and such are referenced by the forwarding plane, often with special purpose circuitry to make the reference as fast as possible. If a single processor on a network device is responsible to respond to administrative commands that create and maintain the device&#39;s configuration (such as routing tables), as well as for the heavy load of forwarding, it might either slow down the forwarding or be very slow to respond to the management commands. Thus, network devices have multiple processors (e.g. chips), some to respond to management functions and the most important, special purpose, and expensive processors to implement the forwarding functions. These levels of functions are grouped: Forwarding Plane moves packets from input to output, also called the Data Plane; Control Plane determines how packets should be forwarded; management plane uses methods of configuring the control plane. Most of the heavy work is done in the forwarding plane, with special purpose processors, as mentioned. The management plane interacts with the administrator or automation. The control plane takes the instruction from the management plane and interacts with the tables that the forwarding plane needs. 
     By way of example using routing updates, the forwarding plane uses current routing table to send packets. The control plane is responsible for updating the routing table with updates from other routers, when a new route is presented, or if a router or path fails and alternate routes should be calculated and distributed. The management plane described which routing protocol to use and perhaps some personalization, such as the routers open shortest path first (OSPF) area number. 
     One benefit of centralizing the control plane is allowing forwarding decisions to be made globally across the SDN domain rather than at each hop. Normally, a spanning tree (a control plane process) is needed to guard against loops because no individual switch knows what the entire network looks like. However, if the control plane functions for all switches are offloaded to a central controller (e.g., such as SDN controller as one of the endpoint devices  210  according to one or more embodiments), that controller can view the complete network and install forwarding decisions to each controlled switch based upon the desired end-to-end path for each flow while keeping all links active. 
     Another benefit of having a central controller is a programming interface to allow other applications to control network resources and influence forwarding decisions. For example, if a virtual machine is moved from one physical host to another, the controller could automatically migrate any associated firewall or Quality of Service (QoS) policies (forwarding plane) on the network. This removes the need for a human administrator to reconfigure network resources and allows the entire network to quickly adjust to the processing requirements. 
     Plane separation can separate the forwarding and control functions. The forwarding plane (or data plane) is the primary function of the switch, moving packets from the sending port to the receiving port. In SDN, the functions the forwarding plane can perform on a packet are reduced to forward, drop, consume, and replicate. The control plane includes the protocols and algorithms to modify how the forwarding plane does its job, traditionally setting up routing tables and access control lists. In SDN, it manages the tables the provide the instructions for the forwarding plane. Traditionally, these co-reside in the physical switch. Initially, they were on the same hardware, but the control functions would take precious CPU cycles from the forwarding functions and either cause the forwarding functions to slow down unacceptably or cause the control functions to have very poor response time. A control function running on a general-purpose processor that managed the forwarding functions running on the high-speed and specialized switching processor fixed that. However, the control function was still highly integrated with the hardware, and thus proprietary and closed. Other characteristics of SDN switches and controllers are that they provide a simplified device, centralized control, network automation and virtualization, and openness. 
     OpenFlow was intended to handle all required network functions. Thus, OpenFlow is to determine characteristics of each packet, with the fields shown in gray both within and above the network layer where they are located, as shown in  FIGS.  3 A  and  3 B. Particularly,  FIG.  3 A  depicts fields examined in OpenFlow match tables used to process, for example, L2, L3, and L4 packets. Recall the TCP segment is the payload of the IP datagram, which is the payload of the Ethernet frame, so all fields are available when looking at the L2 Ethernet frame that comes into any TCP/IP network switch. For comparison,  FIG.  3 B  depicts SAN fields, that are present in all FC frames, examined in match tables in accordance with one or more embodiments of the present invention. 
     The processing of an OpenFlow switch is shown in  FIG.  4   . A network user or device sends a packet at stage  401 . The OpenFlow switch can examine the contents of the packet, as well as collect additional metadata such as the ingress port number at stage  402 . The fields of the incoming packet are compared against the match fields in the match table. OpenFlow defines a match table which contains entries for fields found in an incoming packet. Multiple matches are resolved by the priority field specification. If no match is found, there is a default instruction at stage  404 , but if a match is found the instructions field specifies what the switch should do with the packet at stage  404 . The instruction is implemented at stage  405  can include: forward to a port (or replicate to multiple ports); send to the controller for further processing (which might cause a new match rule to be created and sent to the switch for the next such packet); drop the packet (e.g. firewall rule is not satisfied); and send the packet to the “normal” TCP/IP switch processing, which might be forwarding via layer 2, or routing via layer 3 functions. 
     The next iteration of the OpenFlow specification addressed some issues that were identified with early prototypes and usage scenarios. The primary addition was group tables which simplified the management of the control plane directives where multiple objects with the same rules would point to the same group table, rather than replicate the rules. The processing is shown in  FIG.  5   . In the OpenFlow switch processing in v1.1, the additional group table processes are shown at stages  501  and  506 . Stage  507  in  FIG.  5    is analogous to  405  in  FIG.  4   . Group-Based Policy (GBP) is a concept from OpenStack and the Neutron virtual network process. OpenStack allows Local Area Network domains to be summarized and not treated as a special type of network. Group Tables in OpenFlow further enable that concept. 
     The changes in v1.2 of the OpenFlow specification include the addition of a new match type, called “Extensible Match” types, which greatly enhanced and simplified the match tables and which are used in accordance with one or more embodiments of the invention to implement compatibility on the hardware of a SAN being managed using SDN as discussed herein. Extensible Matches changed static length match fields into variable length. Now, all match table entries are where the OFPMT_OXM field in the match type header has value 0x0001, shown in  FIG.  6   . It is noted that the name is made up of OFP for “OpenFlow Protocol”, MT for “Match Type”, and OXM for “Open eXtensible Match”. An extensible match field can include the following: existing match classes from OpenFlow v1.0 or v1.1, values 0x0000-0x7000; new match classes that might be officially added to the specification, values 0x8000-0xFFFE; and an “Experimenter” class, value 0xFFFF, which is utilized for dynamic additions to the switch function to allow for the implementation of the SAN being managed using SDN in accordance with one or more embodiments. 
     An OpenFlow 1.2 extensible field table entry is a header (with type=0x0001), shown in  FIG.  6   , followed by zero or more oxm_fields, shown in  FIG.  7   .  FIG.  6    depicts ofp_match using OpenFlow v1.3 match header. In  FIG.  6   , the body of the oxm_fields are TLV (Type, Length, Value) format. The basic format of an OpenFlow match field, without header, is shown in  FIG.  7   .  FIG.  7    depicts OXM_fields in OpenFlow v1.3 Extensible Match Field format. 
     In  FIG.  7   , the type is the combination of the OXM_class and OXM_field, to make a 23-bit long OXM_type. OXM_class, 16 bits long, describes the type of match record. OXM_field, 7 bits long, specifies a match field within the class. Next, the OXM_hasmask field is a single bit that specifies if there is a bitmask in the match payload. The OXM_Length, 8 bits long, specifies the length of the match payload. Finally, the payload or value of the match is padded to make the whole match field, including the header, a multiple of 8 bytes long. If the OXM_Hasmask bit is set to 1, the payload is twice as long as the value, and the following applies: (i) A mask bit position containing a 1 means “match exactly”. When a mask bit is 1, if the value in the same bit position of the payload matches the incoming packet contents, the state continues to be “matches” until all the bits are compared. If the value is not the same in any bit position, the state is “does not match”. (ii) A mask bit position containing a 0 means “ignore” or “don&#39;t care”. When a mask bit is 0, whatever value is in the same bit position of the payload value does not change the overall “matches” or “does not match” state. 
       FIG.  8    depicts an OpenFlow extensible match field for a destination Internet Protocol version 4 (IPv4) address (i.e. IP address). A similar example, except for all addresses in the Class C subnet of 192.168.1.0/24, is shown in  FIG.  9    (e.g. IP subnet, i.e. address with bitmask). Note that if the oxm_hasmask bit-length field is 1, the OXM_Length is doubled, and the bitmask (shaded) follows the field containing the bits to match.  FIG.  9    depicts an OpenFlow extensible match field for a destination IPv4 subnet. An example of a match of destination port  80  is shown in  FIG.  10    (e.g. TCP port), where the OXM_Class value is used for the TCP destination port number, TCP_DST (14 in decimal, 0E in hexadecimal). An example of a match of both destination IP address of 192.168.1.1 and destination port  80  is shown in  FIG.  11    (e.g. a TCP/IP address and port combined).  FIG.  11    depicts an OpenFlow extensible match field for a destination IP address and destination TCP port. 
     As discussed herein, one or more embodiments of the invention utilize the experimenter match fields of the extensible match field to enable SAN identifiers to be utilized by SAN switches incorporating an SAN architecture. Particularly, one or more embodiments use SDN to manage SAN switches. 
     II. Using Match Tables of Software Defined Networking to Manage Storage Area Networks 
     One or more embodiments of the invention describe techniques to use the experimenter fields in the match table of SDN to manage SAN switches  230 . By way of example, various examples using OpenFlow to manage SAN structures are described in accordance with one or more embodiments, and it should be appreciated that embodiments are not limited to OpenFlow software. OpenFlow specification 1.2 defines an “experimenter” match class, value 0xFFFF. As noted herein, the header for all match type fields was changed to be the “extensible match type”, as shown in  FIG.  6   . Match fields defined before v1.2 have a “standard” match type, to allow co-existence. 
     If an OpenFlow table entry has the extensible match class, it has extensible fields to describe TLV (type-length-value) match entries which are utilized according to one or more embodiment. Particularly, one or more embodiments define a variety of new experimenter match class fields illustrated in  FIG.  12    for use with SAN switches managed using SDN. Using OpenFlow Extensible Match type experimenter fields,  FIG.  12    depicts a variety of new SAN class and field combinations for SAN objects according to one or more embodiments. With those structures illustrated in  FIG.  12   , SDN switches can match on the WWPN (world wide port name), the Domain and Port Address, the Exchange ID of the source or destination in a SAN, and/or any combination, both locally and between distant sites. These fields are described further in detail herein. 
     By way of example using the Ubuntu® open switch control command open virtual switch open flow control (ovs-ofctl), these extensible match field types can be added to existing OpenFlow switches, as shown in Table. Table 1 illustrates Ubuntu commands to add extensible match types for SAN switches managed by SDN according to one or more embodiments. The example commands in Table 1 correspond to the example extensible match type experimenter fields in  FIG.  12   , which are executed by the SAN switch managed using SDN according to one or more embodiments. It is noted that switch01 would be replaced with TCP/IP-address or similar directive and is a place holder. 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
               
                   
               
             
            
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Source 
                  “{class=0xffff,type=0x71,len=8}-&gt;tun_metadata1” 
               
               
                 WWN 
                 ovs-ofctl add-flow switch01 tun_metadata1=0071,actions=controller 
               
               
                 (world wide 
               
               
                 name) 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Destination 
                  “{class=0xffff,type=0x72,len=8}-&gt;tun_metadata2” 
               
               
                 WWN 
                 ovs-ofctl add-flow switch01 tun_metadata2=0072,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Source 
                  “{class=0xffff,type=0x73,len=1}-&gt;tun_metadata3” 
               
               
                 Domain ID 
                 ovs-ofctl add-flow switch01 tun_metadata3=0073,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Destination 
                  “{class=0xffff,type=0x74,len=1}-&gt;tun_metadata4” 
               
               
                 Domain ID 
                 ovs-ofctl add-flow switch01 tun_metadata4=0074,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Source Port 
                  “{class=0xffff,type=0x75,len=1}-&gt;tun_metadata5” 
               
               
                 ID 
                 ovs-ofctl add-flow switch01 tun_metadata5=0075,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Destination 
                  “{class=0xffff,type=0x76,len=1}-&gt;tun_metadata6” 
               
               
                 Port ID 
                 ovs-ofctl add-flow switch01 tun_metadata6=0076,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Source 
                  “{class=0xffff,type=0x77,len=1}-&gt;tun_metadata7” 
               
               
                 Arbitrated 
                 ovs-ofctl add-flow switch01 tun_metadata7=0077,actions=controller 
               
               
                 Loop ID 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Destination 
                  “{class=0xffff,type=0x78,len=1}-&gt;tun_metadata8” 
               
               
                 Arbitrated 
                 ovs-ofctl add-flow switch01 tun_metadata8=0078,actions=controller 
               
               
                 Loop ID 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Source Port 
                  “{class=0xffff,type=0x79,len=2}-&gt;tun_metadata9” 
               
               
                 Number 
                 ovs-ofctl add-flow switch01 tun_metadata9=0079,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Destination 
                  “{class=0xffff,type=0x7a,len=2}-&gt;tun_metadata10” 
               
               
                 Port Number 
                 ovs-ofctl add-flow switch01 tun_metadatal0=007a,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Source 
                  “{class=0xffff,type=0x7b,len=4}-&gt;tun_metadata11” 
               
               
                 Exchange ID 
                 ovs-ofctl add-flow switch01 tunmetadata11=007b,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Destination 
                  “{class=0xffff,type=0x7c,len=4}-&gt;tun_metadata12” 
               
               
                 Exchange ID 
                 ovs-ofctl add-flow switch01 tun_metadata12=007c,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Source VID 
                  “{class=0xffff,type=0x7d,len=2}-&gt;tun_metadata11” 
               
               
                 (VSAN/FID) 
                 ovs-ofctl add-flow switch01 tun metadata11=007d,actions=controller 
               
               
                 Add SAN 
                 ovs-ofctl add-TLV-map switch01 
               
               
                 Destination 
                  “{class=0xffff,type=0x7e,len=2}-&gt;tun_metadata12” 
               
               
                 VID 
                 ovs-ofctl add-flow switch01 tun_metadata12=007e,actions=controller 
               
               
                 (VSAN/FID) 
               
               
                   
               
            
           
         
       
     
     Various examples of at least a part of match tables in SDN architecture to be used with SAN switches  230  are described herein and are not meant to be limited. Although specific example match tables are described, one or more experimenter fields in the example match tables can be combined as understood by one skilled in the art. 
     Turning to an example for SDN experimenter match class for SAN World Wide Name for execution by the SAN switch  230  managed by SDN, a match table could have an entry for a OFPXMCF_SANSWWN or OFPXMCF_SANDWWN (SAN Source and Destination WWPN, respectively), or both, according to one or more embodiments. Particularly,  FIG.  13    depicts an example match table with OpenFlow Extensible Match field OFPXMCF_SANSWWN according to one or more embodiments. In  FIG.  13   , the length is 16 bytes. The content of the match table includes 4 bytes for the OXM header which includes 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x10 (that is, 0010 in hexadecimal). The content includes WWN match class which includes 2 bytes for the OXM_Class, value 0xFFFF, indicating the experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x71 (destination WWN) or 0x72 (source WWN); and 1 byte for the length of the match payload, OXM_Length, value of 0x08. Also, the content includes 8 bytes for the WWN value in hexadecimal,  FIG.  13    showing an example WWN typically expressed as 10:00:c4:f5:7c:1d:25:a0. 
     Regarding an example SDN experimenter match class for SAN Domain Identifier for execution by the SAN switch  230  managed by SDN, a match table could have an entry for a OFPXMCF_SANSDID and OFPXMCF_SANDDID (SAN Source and Destination Domain ID, respectively), or both, according to one or more embodiments. Particularly,  FIG.  14    depicts an example match table with OpenFlow Extensible Match field OFPXMCF_SANSDID according to one or more embodiments. In  FIG.  14   , the length is 16 bytes. The content of the match table includes 4 bytes for the OXM header which include 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x09. In the match table, the DID match class includes 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x73 (destination Domain ID) and 0x74 (source Domain ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal,  FIG.  14    showing an example domain ID of 1. The content includes 7 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Regarding an example for SDN experimenter match class for SAN Port Address for execution by the SAN switch  230  managed by SDN, a match table could have an entry for a OFPXMCF_SANSPID or OFPXMCF_SANDPID (SAN Source and Destination Port ID, respectively), or both, according to one or more embodiments. Particularly,  FIG.  15    depicts an example match table with OpenFlow extensible match field OFPXMCF_SANSPID according to one or more embodiments. In  FIG.  15   , the length is 16 bytes. In the match table, the content includes 4 bytes for the OXM header which includes 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x09. In the match table in  FIG.  15   , the PID match class includes 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x75 (destination Port ID) or 0x76 (source Port ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Port ID, value in hexadecimal, 0xC0 as an example. Also, the content includes 7 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Turning to an example for SDN experimenter match class for SAN Arbitrated Loop Address for execution by the SAN switch  230  managed by SDN, a match table could have an entry for a OFPXMCF_SANSALA or OFPXMCF_SANDALA (SAN Source and Destination Arbitrated Loop Address, respectively), or both, according to one or more embodiments. Particularly,  FIG.  16    depicts an example match table with OpenFlow Extensible Match field OFPXMCF_SANSALA according to one or more embodiments. In  FIG.  16   , the example format has length of 16 bytes, and the content includes 4 bytes for the OXM header which has 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x09. In the match table of  FIG.  16   , the ALA match class includes the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x77 (destination Arbitrated Loop Address) or 0x78 (source Arbitrated Loop Address); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Arbitrated Loop Address, value in hexadecimal, 0x80 as an example. In  FIG.  16   , the match table also includes 7 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Regarding an example for SDN experimenter match class for SAN Port Number for execution by the SAN switch  230  managed by SDN, a match table could have an entry for a OFPXMCF_SANSPNO or OFPXMCF_SANDPNO (SAN Source and Destination switch Port Number, respectively), or both, according to one or more embodiments. Particularly,  FIG.  17    depicts an example match table with OpenFlow Extensible Match field OFPXMCF_SANSPNO according to one or more embodiments. The port number on the SAN switch chassis is constant based on the physical location, but the port ID (also called the port address) is dynamically defined on vendor SAN switches (e.g., both Cisco® and Brocade® SAN switches). The port address is used for the F_Port address obtained in the FLOGI (i.e., the Fabric Login phase of Fibre Channel Standard link initialization) and is also used in the source-based routing of the mainframes&#39; I/O definition. In the match table in  FIG.  17   , the length is 16 bytes, and the content includes 4 bytes for the OXM header which includes 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x09. In the match table in  FIG.  17   , the content includes the following: NUM match class which includes 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x79 (destination Port Number) or 0x7A (source Port Number); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 2 bytes for the Port Number, value in hexadecimal, 0x0002 as an example. The match table in  FIG.  17    also has 6 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Turning to an example for SDN experimenter match class for SAN Exchange Identifier for execution by the SAN switch  230  managed by SDN, a match table could have an entry for a OFPXMCF_SANSXID or OFPXMCF_SANDXID (SAN Source and Destination Exchange ID, respectively), or both, according to one or more embodiments. Particularly,  FIG.  18    depicts an example match table with OpenFlow Extensible Match field OFPXMCF_SANSXID according to one or more embodiments. In the match table in  FIG.  18   , the length is 16 bytes, and the content includes 4 bytes for the OXM header having: 2 bytes for the OFPMT_OXM=OFPMT_XM=1; 2 bytes for the length of the match fields payload, 0x0A; and 2 bytes for the OXM_Class, value 0xFFFF, experimenter class. The content of XID match class includes the following: 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x7B (destination Exchange ID) or 0x7C (source Exchange ID); 1 byte for the length of the match payload, OXM_Length, value of 0x02; and 2 bytes for the Exchange Identifier, value in hexadecimal, 0x8b4f as an example. The match table in  FIG.  18    also has 6 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Regarding an example for SDN experimenter match classes for SAN VID (which includes VSAN ID and FID) for execution by the SAN switch  230  managed by SDN, a match table could have an entry for a OFPXMCF_SANSVID or OFPXMCF_SANDVID (SAN Source and Destination VSAN/FID, respectively), or both, according to one or more embodiments. Particularly,  FIGS.  19 A and  19 B  together depict an example match table with OpenFlow Extensible Match field OFPXMCF_SANSVID according to one or more embodiments. In the match table in  FIGS.  19 A and  19 B , the length is 16 bytes, and the content includes 4 bytes for the OXM header which includes 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x0A. As illustrated in  FIGS.  19 A and  19 B , the match table includes the VID match class which include the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x7D (source VSAN/FID) or 0x7E (destination VSAN/FID); 1 byte for the length of the match payload, OXM_Length, value of 0x02;and 2 bytes for the VSAN/FID, value in hexadecimal, 0x0080 as an example. In  FIGS.  19 A and  19 B , the match table also has 6 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Turning to an example for SDN experimenter match classes for SAN FICON Link Address for execution by the SAN switch  230  managed by SDN,  FIG.  20    depicts an example match table having OpenFlow Extensible Match field OFPXMCF_SANSDID and _SANSPID according to one or more embodiments. The FICON Link Address is a combination of the Domain ID and the Port Address. Both the DID and PID are to be either for the destination (_SANDDID and _SANDPID combined) or the source (_SANSDID and _SANSPID combined). Rather than create a new match class, these can be combined as shown in  FIG.  20    according to one or more embodiments. In the match table in  FIG.  20   , the length is 16 bytes, and the content includes 4 bytes for the OXM header which includes 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x0E. The content of the match table in  FIG.  20    includes the Domain ID match class having the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x73 (source Domain ID) or 0x74 (destination Domain ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal, 0x01 as an example. The content of the match table in  FIG.  20    includes the Port ID match class having the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x75 (source Port ID) or 0x76 (destination Port ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Port ID, value in hexadecimal, 0xC0 as an example. In  FIG.  20   , the match table also has 2 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Turning to an example for SDN experimenter match classes for SAN FCP 10-bit Link Address for execution by the SAN switch  230  managed by SDN,  FIG.  21    depicts an example match table having OpenFlow Extensible Match field OFPXMCF_SANxPID and _SANxALA according to one or more embodiments. The FCP Link Address can take ports from the Arbitrated Loop Address field in order to have more than 256 link addresses in a SAN switch domain. Rather than create a new match class, the Port Address and Arbitrated Loop Address can be combined as shown in  FIG.  21    according to one or more embodiments. Both the PID and ALA are to be either both for the destination or the source. In the match table in  FIG.  21   , the length is 16 bytes, and the content includes 4 bytes for the OXM header including 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x0E. The match table in  FIG.  21    includes the Port ID match class, the PORT ID match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class, 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x75 (source Port ID) or 0x76 (destination Port ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Port ID, value in hexadecimal, 0x01 as an example. The match table in  FIG.  21    includes the Arbitrated Loop Address match class, the Arbitrated Loop Address match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x77 (source Arbitrated Loop Address) or 0x78 (destination Arbitrated Loop Address); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal, 0xC0 as an example. In  FIG.  21   , the match table include also has 2 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Regarding an example for SDN experimenter match classes for SAN Domain and FCP 10-bit Link Address for execution by the SAN switch  230  managed by SDN,  FIG.  22    depicts an example match table using OpenFlow Extensible Match field OFPXMCF_SANxDID, xPID, and xALA according to one or more embodiments. A full FCP link address with the domain ID and using 10-bit addressing would need the ALA field as well as the port address field. One or more embodiments can combine 3 match fields as shown in  FIG.  22    according to one or more embodiments. All of the DID, PID and ALA are to be either for the destination or the source. In the match table in  FIG.  22   , the length is 16 bytes, and the content includes 4 bytes for the OXM header including 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 0x13. The match table in  FIG.  22    includes the Domain ID match class, the Domain ID match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x73 (source Domain ID) or 0x74 (destination Domain ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal, 0x01 as an example. The match table in  FIG.  22    includes the Port ID match class, the Port ID match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x75 (source Port ID) or 0x76 (destination Port ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Port ID, value in hexadecimal, 0xC0 as an example. The match table in  FIG.  22    includes the Arbitrated Loop Address match class, the Arbitrated Loop Address match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x77 (source Arbitrated Loop Address) or 0x78 (destination Arbitrated Loop Address); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal, 0x80 as an example. In  FIG.  22   , the match table includes 5 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     Turning to an example for SDN experimenter match classes for SAN VSAN/FID, Domain ID, and Link Address for execution by the SAN switch  230  managed by SDN,  FIG.  23    depicts an example match table using OpenFlow Extensible Match field OFPXMCF_SANxVID, xDID, and xPID according to one or more embodiments. In Fibre Channel and FICON, physical SAN switches can be logically divided into subsets called a virtual SAN or a fabric, which has a numeric identifier. Ports in a physical switch can be placed in a VSAN or fabric. Cisco® designates this the Virtual SAN ID, or VSAN ID (or number); Broadcom/Brocade designates this the Fabric ID, or FID; and herein physical SAN switches logically divided into subsets called a virtual SAN or a fabric are designated as the virtual ID (VID) in order to represent and/or include the Virtual SAN ID (VSAN ID or number) as well as the Fabric ID (FID)). Currently, the VSAN/FID is a number from 0 to 256 which will fit in one byte, but to allow for expansion (as the analogous Ethernet VLAN ID had to be) it is two bytes herein according to one or more embodiments. Multiple physical switches can be connected with E_Ports (expansion ports) or VE_Ports (Virtual Expansion ports using FCIP). Thus, a VID can span physical switches. Generally, all Fibre Channel communication between ports, and in the same zone if zoning is applied, is within the same VID. There are proprietary techniques to bypass that restriction, such as Fibre Channel Routing where the switches are actively aware of ports that extend beyond their VID, or “ignore VID” where the switches do not enforce that the ports must be in the same VID in order to communicate. Thus, a complete SAN ID is a combination of the VID, Domain ID, and the Port Address. The VID, DID, and PID are either for the destination (_SANDVID, _SANDDID, and _SANDPID combined), or the source (_SANSVID, _SANSDID, and _SANSPID combined). Rather than create a new match class, one or more embodiments can combine 3 match fields as shown in  FIG.  23   . All of the VID, DID, and PID are to be either for the destination or the source. According to one or more embodiments, the match table in  FIG.  23    includes a length of 24 bytes, and the content includes 4 bytes for the OXM header including 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 20 or 0x14. The match table in  FIG.  23    includes the VSAN/Fabric ID match class, the VSAN/Fabric ID match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x7D (source VID) or 0x7E (destination VID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 2 bytes for the VID, value in hexadecimal, 0x0080 as an example. Also, the match table in  FIG.  23    includes the Domain ID (DID) match class, the Domain ID (DID) match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x73 (source Domain ID) or 0x74 (destination Domain ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal, 0x01 as an example. The match table in  FIG.  23    includes the Port ID (PID) match class, the Port ID (PID) match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x75 (source Port ID) or 0x76 (destination Port ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Port ID, value in hexadecimal, 0xC0 as an example. In  FIG.  22   , the match table includes 7 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     As another example combining  FIGS.  22  and  23   ,  FIG.  24    shows that a VID could also prefix a 10-bit link address like the SDN experimenter match classes for SAN Domain and FCP 10-bit Link Address discussed herein according to one or more embodiments. Particularly,  FIG.  24    depicts an example match table using OpenFlow Extensible Match field OFPXMCF_SANxVID, xDID, xPID, and xALA according to one or more embodiments. According to one or more embodiments, the match table in  FIG.  24    includes a length of 32 bytes, and the content includes 4 bytes for the OXM header which includes 2 bytes for the OFPMT_OXM=OFPMT_XM=1 and 2 bytes for the length of the match fields payload, 25 or 0x19. In the match table in  FIG.  24   , the content includes the VSAN/Fabric ID match class, the VSAN/Fabric ID match class including the flowing: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class, 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x7D (source VID) or 0x7E (destination VID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 2 bytes for the VID, value in hexadecimal, 0x0080 as an example. In the match table in  FIG.  24   , the content includes the Domain ID (DID) match class, the Domain ID (DID) match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x73 (source Domain ID) or 0x74 (destination Domain ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal, 0x01 as an example. In the match table in  FIG.  24   , the content includes the Port ID (PID) match class, the Port ID (PID) match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x75 (source Port ID) or 0x76 (destination Port ID); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Port ID, value in hexadecimal, 0C0 as an example. Also, in the match table in  FIG.  24   , the content includes the Arbitrated Loop Address (ALA) match class, the Arbitrated Loop Address (ALA) match class including the following: 2 bytes for the OXM_Class, value 0xFFFF, experimenter class; 1 byte for the OXM_Field (and OXM_HASMASK bit), value either 0x77 (source Arbitrated Loop Address) or 0x78 (destination Arbitrated Loop Address); 1 byte for the length of the match payload, OXM_Length, value of 0x01; and 1 byte for the Domain ID, value in hexadecimal, 0x80 as an example. In  FIG.  24   , the match table includes 4 pad bytes not examined but required to make the structure a multiple of 8 bytes long. 
     According to one or more embodiments, example structures (which can be generated by SDN controllers (e.g., one or more endpoint devices  210  as the SDN controller) have been defined as match tables including experimenter fields constructed as discussed herein to be parsed, matched to incoming traffic (which can be frames, packets, etc.) from various types of endpoint devices, and routed by the SAN switches  230  managed by SDN and/or SDN architecture to the appropriate end device, another SAN switches  230  managed by SDN, etc. By using the experimenter match field generated by SDN controllers (e.g., one or more endpoint devices  210  as the SDN controller) as discussed herein, SAN-specific addressable items such as WWPNs, SAN port address, FID (Fabric ID), and PID (switch ID) are utilized in SDN rules to control SAN traffic by SAN switches  230  managed by SDN according to one or more embodiments. Managing SAN traffic (and optionally TCP/IP traffic i.e. LAN traffic) using SAN switches  230  managed by SDN according to one or more embodiments is different and improved over any SDN switch that is only for TCP/IP networks (i.e., IP address, port, VLAN ID, MAC address). As discussed herein, SAN switches  230  can manage SAN traffic using SDN as well as TCP/IP traffic using SDN. SDN virtualizes existing Internet Protocol (IP) networks, allows flexible and rapid response to a variety of requirements, allows network engineers to simplify, automate network management, use open protocols, reduce cost, and innovate. Traditional control of TCP/IP networks is performed by highly-skilled experts who need a lot of training and experience. They tend to specialize, to the point where one vendor has a series of certifications, but they might be useless in a different network environment. The customers tend to be locked in by a network infrastructure provider, because of lack of inter-operability and the expense of two types of experts. The customers (or other vendors or academia) cannot innovate because the vendor&#39;s products are proprietary and (usually) non-extendable. Also, one vendor has multiple network types, applied to two different infrastructure models. All of these reasons make it difficult to simplify and automate. It should be appreciated that SDN switches (modified as discussed herein) are immensely cheaper and easier to manage and are interoperable using the techniques disclosed in one or more embodiments. Further, according to one or more embodiments, a LAN SDN switch could be extended to be a SAN SDN switch  230  thereby routing SAN traffic and TCP/IP traffic. Traffic forwarding is the main purpose of the data (or forwarding) plane, and both LANs and SANs are preoccupied with that (e.g. special circuits for that function). However, they have different flow controls and while LAN firewalls have ACLs (Access Control Lists), zoning is used in SANs. LANs are preoccupied with routing and have many routing protocols with many administration techniques; SANs have much less so (although it is important) and have only one routing technique that is (relatively) difficult to administer. One or more embodiments provide the ability to implement even more routing techniques, some of which might be better for LANs, some for SANs, and/or some for combined SAN over LAN (i.e. FCIP). All the routing techniques could be administered from a single controller (e.g. SDN controller of an endpoint device  210 ) for simplification (i.e., no need to manage each SDN SAN switch  230  separately thereby reducing labor and the possibility for errors). 
     III. Software Defined Networking Managed Storage Area Network Examples 
     In accordance with one or more embodiments, this section illustrates examples to demonstrate that traditional SAN routing/functions can be implemented with SDN-style matching/forwarding tables using SAN switches  230  managed by SDN and/or SDN architecture, while using the modified match tables discussed herein. The various examples are for ease of understanding and illustration purposes and are not meant to be limiting. In various examples, the SDN controller (e.g., one or more endpoint devices  210  configured as the SDN controller) having an SDN architecture is configured to generate match tables having the SDN architecture and download the match tables to SDN managed SAN switches  230  according to one or more embodiments. The SAN switches  230  managed using SDN are configured to read incoming frames from source endpoint devices  210  and route traffic to destination endpoint devices  210  over the SAN  200  using the downloaded match tables according to one or more embodiments. Various examples provide illustrations of how the modified match tables are used in the SAN  200  by SDN managed SAN switches  230  to route traffic according to one or more embodiments. In the examples in  FIGS.  25 ,  27 ,  29 ,  31 ,  33 A,  33 B,  33 C,  35 A,  35 B,  35 C,  37 A, and  37 B , the experimenter field of the extended field of the match table is depicted, and match tables are abbreviated for conciseness such that the header information is not shown. In the modified match tables, the source (S) and destination (D) entries for many types of routing are shown, and the match table has an asterisk “*” for any entry that is not utilized by the SAN switch  230  in SAN  200 . The action entry in the match table denotes that action to be taken by SDN managed SAN switches  230 . 
       FIGS.  26 ,  28 ,  30 ,  32 ,  34 ,  36 ,  38 , and  39    illustrate various commands that may be executed by the SDN managed SAN switches  230  to perform the routing in the match tables according to one or more embodiments. For explanation purposes and not limitation, these commands are illustrated in Ubuntu syntax. Ubuntu is an open source version of the Linux® operating system. Ubuntu has virtualized network switches and routers and has commands that manage them with “ovs” (open virtual switch) commands to manage normal Layer 2 (Ethernet and VLAN) and Layer 3 (IP routing) functions. Ubuntu implemented OpenFlow protocols with ovs-ofctl commands (for open virtual switch via OpenFlow control). There are other OpenFlow control products with different commands and graphical interfaces that simplify and enhance the management of OpenFlow-compliant networks. For illustration purposes and not limitation, the ovs-ofctl commands are utilized as examples according to one or more embodiments. 
     Now turning to an example for FICON destination Domain ID and Port ID,  FIG.  25    depicts an SDN-managed SAN switch  230  that routes DID/PID to port according to one or more embodiments. FICON I/O frames (shown in  FIG.  3 B ) send destination Domain and Port address from Host  1  (e.g., endpoint device  210 ), so the SDN-controlled SAN switch  230  can match these frame fields in the match table and send to the correct port. Particularly,  FIG.  25    illustrates an example of a FICON Host (e.g., endpoint device  210 ) sending and I/O frame to 0104, which is switch domain  01 , port address  04  to SAN switch  230 . By processing via SAN switch  230 , the match table for DDID=01 and DPID=04 is used to send the frame to fiber channel (FC) port  4 . The SAN switch  230  is managed and executed using SDN architecture and relies on a modified match table using SDN architecture according to one or more embodiments. The SDN controller as endpoint device  210  in  FIG.  25    can execute the commands depicted in  FIG.  26    and direct SDN SAN switch  230  to update its match tables according to one or more embodiments.  FIG.  26    depicts example commands executed by the SDN controller as endpoint device  210  to direct SDN SAN switch  230  to send SAN traffic for a Domain ID/Port Address to a port according to one or more embodiments. In  FIG.  26   , Ubuntu commands instruct the OpenFlow switch (i.e., SAN switch  230  managed by SDN) at IP address 10.10.10.111 to route all traffic destined for domain ID  01  and port address  04  to port FC 4 . As can be seen in  FIGS.  25  and  26   , SDN controller (e.g., endpoint device  210 ) will create match table entries that are used by the SDN SAN switch  230 , and the match table entries enable SDN executing on the SAN switch  230  to send FICON frames to the desired destination port, according to one or more embodiments. 
     Turning to an example for FCP WWN to port,  FIG.  27    depicts an SDN-managed SAN switch  230  that routes WWN to port according to one or more embodiments. For FCP, a name server is to have the correlation of WWN to Port. This name server could be implemented as a function of the base SAN switch (recall “normal switch function” of stages  405  and  507  is an option for the action of a match table entry), or as a Virtual Service on the SDN SAN Switch, SDN controller, or another accessible server, or by observing the PLOGI (Physical Login) frames that are sent during the FCP Link Initialization standard process.  FIG.  27    illustrates an FCP host (e.g., endpoint device  210 ) sending (e.g., a frame) containing a destination WWN. The SDN switch  230  can obtain this information from the incoming frame and the SDN controller (e.g., endpoint device  210 ) that provides the match table, and the SDN switch  230  adds a match table entry in the match table for the port that has that WWN. The SDN controller as endpoint device  210  in  FIG.  27    can execute the commands depicted in  FIG.  28    and direct the SDN SAN switch  230  to create match table entries according to one or more embodiments.  FIG.  28    depicts example commands that result in the FCP/FICON match table entries shown in the SAN switch  230  to send SAN traffic for a WWN to a port according to one or more embodiments. In  FIG.  28   , Ubuntu commands instruct the OpenFlow switch (i.e., SAN switch managed by SDN) at IP address 10.10.10.111 to route all traffic destined for WWN 10:00:c4:f5:7c:1d:25:a0 to port FC 4 . As can be seen in  FIGS.  27  and  28   , SDN controller (e.g., endpoint device  210 ) is configured to create match table entries that are stored and used by the SAN switch  230 , and the match table entries enable SDN executing on the SAN switch  230  to correlate WWNs to ports according to one or more embodiments. 
     Regarding an example for FCP Zoning by WWN,  FIG.  29    depicts an SDN-managed SAN switch  230  that routes to a Zone by WWN according to one or more embodiments. FCP requires zones. One method of zoning is with WWNs. In the match table and as executed by SAN switch  230 ,  FIG.  29    illustrates match table entries that allow 2 ports to communicate based on WWN, in the first 2 rows, and drops any frames destined for these ports from any other port, as shown in the last 2 rows. The SAN switch  230  in  FIG.  29    can execute the commands depicted in  FIG.  30    according to one or more embodiments.  FIG.  29    depicts example commands executed by the SAN switch  230  to implement a SAN zone using WWNs according to one or more embodiments. In  FIG.  30   , Ubuntu commands instruct the OpenFlow switch (i.e., SAN switch  230  managed by SDN) at IP address 10.10.10.111 to allow traffic between the host&#39;s WWN (e.g., Host  1  as endpoint device  210 ) and the device&#39;s WWN (e.g., device  1  as another endpoint device  210 ) and drop traffic for those destinations from any other WWN. Since higher priority values take precedence, the flows with matching source and destination are used before the “drop traffic to wwn_dst” flow is used, so that the zone allows traffic between ports and does not drop it. 
     It is noted that group tables (discussed herein), added in OpenFlow v1.1 but not shown in this example, could consolidate many rows, so a large zone would not need 
               n   ⁡   (     n   -   1     )     2         
rows for n ports in a zone in one or more embodiments. Likewise, the “conjunction” parameter, also not shown in this example, would allow multiple ports to be in a zone and simplify the table entries, with 1 row per destination port. As can be seen in  FIGS.  29  and  30   , SDN controller (e.g., endpoint device  210 ) is configured to create match table entries that are executed by the SAN switch  230 , and the match table entries enable SDN executing on the SAN switch  230  to perform WWN zoning according to one or more embodiments. It should be appreciated that SDN zoning according to one or more embodiments is much simpler and more efficient compared to proprietary zoning in a SAN switch.
 
     Turning to an example for FCP Zoning by Domain ID and Port Address,  FIG.  31    depicts an SDN-managed SAN switch  230  that routes to a Zone by Domain ID and Port Address according to one or more embodiments. Zones can also use Domain ID (DID) and Port Address ID (PID). In the match table executed by SAN switch  230 , FIG.  31  illustrates example match table entries that allow 2 ports to communicate based on Domain ID and Port Address ID, in the first 2 rows, and drops any frames destined for these ports from any other port, as shown in the last 2 rows.  FIG.  32    depicts example commands executed by the SAN switch  230  to implement a SAN zone using Domain ID and Port Address ID according to one or more embodiments. According to one or more embodiments, it is noted that a zone can be made from a combination of matches for WWNs and Domain ID and Port Address, which is also required in current SAN zones. As can be seen in  FIGS.  31  and  32   , SDN controller (e.g., endpoint device  210 ) is configured to create match table entries that are executed by the SAN switch  230 , and the match table entries enable SDN executing on the SAN switch  230  to perform Domain ID and Port Address zoning according to one or more embodiments. Thus, if an I/O operation from a host (e.g., as an endpoint device  210 ) with a channel attached to FC Port  1  on Switch  1  is destined for device Dev 1  (e.g., another endpoint device  210 ) with destination address 0104, meaning domain ID 0x01 and port 0x04, SDN switch  1  (SDN SAN switch  230 ) examines the incoming FC frame, finds a match with source domain ID=0x01, destination domain ID=0x01, source port ID=0x01 and destination port ID=0x04, and finds the action is to forward the frame to FC port  04 . Similarly, the device response (from  0104  to  0101 ) has a match that is forwarded to FC port  01 . Any other traffic destined for port  0104  or  0101  is dropped. As noted above, it should be appreciated that SDN zoning according to one or more embodiments is much more concise and more efficient compared to proprietary zoning in a SAN switch. 
     Regarding an example for Interswitch Link (ISL) Selection,  FIGS.  33 A,  33 B , and  33 C together depict SDN-managed SAN switches  230  that route according to an ISL selection according to one or more embodiments. Interswitch links (ISLs) connect SAN switches  230  in SAN  200 . FSPF (Fabric Shortest Path First) is used to determine routes between switches in a fabric, which would choose 1 or more ISLs as the egress port. In the match table and executed by SAN switches  230 ,  FIGS.  33 A,  33 B, and  33 C  illustrate example match table entries that send all traffic with a non-local Domain ID to an ISL port according to one or more embodiments.  FIG.  34    depicts example commands executed by the SAN switch  230  to implement InterSwitch Link (ISL) routing according to one or more embodiments. In  FIG.  34   , execution of the commands performing the following: instruct the OpenFlow switch (e.g., Switch  1  as SAN switch  230  managed by SDN) at IP address 10.10.10.111 to send all traffic destined for Domain ID  02  to port FC 3 , and for Domain ID  03  to port FC 2 ; instruct the OpenFlow switch (i.e., Switch  2  as SAN switch  230  managed by SDN) at IP address 10.10.10.122 to send all traffic destined for Domain ID  01  to port FC 2 ; and instruct the OpenFlow switch (Switch  3  as SAN switch  230  managed by SDN) at IP address 10.10.10.133 to send all traffic destined for Domain ID  01  to port FC 2 . As can be seen in  FIGS.  33 A,  33 B,  33 C, and  34   , SDN controller (e.g., endpoint device  210 ) is configured to create match table entries that are executed by the SAN switches  230  (e.g., switches  1 ,  2 ,  3 ), and the match table entries enable SDN executing on the SAN switches  230  to perform inter switch routing over ISLs according to one or more embodiments. Thus, if an I/O operation from a host (e.g., as an endpoint device  210 ) with a channel attached to FC Port  1  on Switch  1  is destined for  0201 , meaning domain ID 0x02 and port 0x01, SDN Switch  1  (SDN SAN switch  230 ) examines the incoming FC frame, finds a match with destination domain ID=0x02 and forwards the frame to FC port  3 . SDN switch  2  examines the incoming frame, finds a match with destination port ID=0x01 and forwards the frame to FC port  1 . Groups, such as ISL trunks, can be handled in versions of OpenFlow (after v1.2). Although not discussed in this example, it should be appreciated that groups (e.g., ISL trunks) can be utilized in one or more embodiments. 
     Turning to an example for FCIP Tunnel Selection,  FIGS.  35 A,  35 B, and  35 C  together depict SDN-managed SAN switches  230  that route an FCIP tunnel according to one or more embodiments. If a connection to another switch in a SAN fabric is through an FCIP link (e.g., a VE_Port or Virtual Expansion port), there has to be a correlation of a GE (gigabit Ethernet) port to a Domain ID, in order to emulate a VE_Port. In the match table and executed by SAN switches  230 ,  FIGS.  35 A,  35 B, and  35 C  illustrate match table entries that send all traffic destined for a remote Domain ID to a GE port.  FIG.  36    depicts example commands executed by the SAN switches  230  in  FIGS.  35 A,  35 B , and  35 C to implement FCIP routing according to one or more embodiments.  FIG.  36    illustrates example commands that perform the following: instruct the OpenFlow switch (i.e., Switch  01  as SAN switch  230  managed by SDN) at IP address 10.10.10.111 to send all traffic destined for Domain ID  02  to port GE 1 , and destined for Domain ID  03  to port GE 2 ; instruct the OpenFlow switch (i.e., Switch  02  as SAN switch  230  managed by SDN) at IP address 10.10.10.122 to send all traffic destined for Domain ID  01  to port GE 1 ; and instruct the OpenFlow switch (i.e., Switch  03  as SAN switch  230  managed by SDN) at IP address 10.10.10.133 to send all traffic destined for Domain ID  01  to port GE 1 . As can be seen in  FIGS.  35 A,  35 B,  35 C, and  36   , SDN controller (e.g., endpoint device  210 ) is configured to create match table entries that are executed by the SAN switches  230 , and the match table entries enable SDN executing on the SAN switches  230  to perform inter switch routing using FCIP links according to one or more embodiments. Also, it is noted how the commands to create an FCIP link in  FIGS.  35 A,  35 B, and  35 C and  36    are concise and similar to the commands that set up ISLs in  FIGS.  33 A,  33 B,  33 C, and  34    according to one or more embodiments, which are both similar to the commands used to set up L2 bridges and L3 routes. Further, it is noted that commands for FCIP tunnels in one or more embodiments are more concise and efficient compared to a proprietary FCIP tunnel configuration. 
     Regarding an example for IPEX Path Selection (TCL),  FIGS.  37 A and  37 B  together depict 2 SDN-managed SAN and LAN switches  230  (which are illustrated as  230   a  and  230   b ) and 1 SDN-managed LAN switch  240  that route IPEX TCL according to one or more embodiments. In the current state of the art, Traffic Control Lists (TCLs) are required to select paths for IPEX communication. Using match tables and executed by SDN SAN switches  230 ,  FIGS.  37 A and  37 B  illustrate example match table entries that send traffic destined for an IP address to an ISL (not shown) or FCIP link, through normal SDN match table entries used to manage TCP/IP/Ethernet flows, according to one or more embodiments.  FIG.  38    depicts example commands executed by the SAN switch  230   a  to implement FCIP routing according to one or more embodiments. Particularly,  FIG.  38    depicts example commands executed by the SAN switches  230   a  in  FIGS.  37 A  and  37 B to implement OpenFlow commands to set up a Brocade® SAN FCIP/IPEX tunnel according to one or more embodiments.  FIG.  38    illustrates example Ubuntu commands that instruct Switch  1  as SAN switch  230   a  (e.g. at IP address 10.10.10.111) to have an FCIP tunnel with IPEX. GE port  1  is assigned the IP address 10.1.1.5 and is attached to SDN switch  240  with IP address 10.10.10.110, which has a route to 10.2.2.5, supplied by the SDN controller (e.g., as one of the endpoint devices  210 ) with instructions in  FIG.  39   . Where in current state-of-the-art SAN, an FCIP Tunnel  24  and circuit  0  must be defined to create a socket between 10.1.1.5 and 10.2.2.5, but an SDN SAN switch  230  can create the same flow with instruction  3802  in  FIG.  38    according to one or more embodiments. Where in the current state-of-the-art SAN, Tunnel  24  has IPEX enabled, but SDN SAN switch  230   a  can create an SDN flow with instruction  3804  in  FIG.  38   . As part of a command package, instructions  3802  and  3804  are sent from SDN controller (e.g. as one of the endpoint devices  210 ) to SDN switch 10.10.10.111 (e.g. SDN SAN switch  230   a ). Lastly, the current state-of-the-art SAN requires a traffic control list (TCL) which allows the virtual tape device (e.g., Tape  1  as endpoint device  210 ) at 10.8.8.5 to communicate with the virtual tape device (e.g., Tape  2  as endpoint device  210 ) at 10.9.9.5. However, this is accomplished in SDN SAN switch  230   a  with instruction  3804  that also describes the route. According to one or more embodiments, the commands shown in  FIG.  38    instruct the Brocade SAN switch at IP address 10.10.10.111 to have the same communication flow as a proprietary configuration, but these Ubuntu OpenFlow control commands are fewer and more concise than the proprietary configuration and use the same SDN commands as used for SDN LAN switches. 
       FIG.  39    illustrates OpenFlow commands to set up the network routes for FCIP/IPEX in which the commands are executed by an intervening router/switch in  FIGS.  37 A and  37 B  according to one or more embodiments. More particularly,  FIG.  39    depicts the OpenFlow commands that will enable communication between the 2 virtual tape devices (e.g., Tape  1  and Tape  2  illustrated as different endpoint devices  210 ) using the intervening router/switch. It is noted these commands may be similar to those for LAN and SAN connections and use the analogous language and constructs. This is more concise than TCLs and fits into a “standard” routing system that is easier to understand and manage. Note that, if required, all the TCL specifications (e.g. port, source and destination, or subnet) can be described in the match table entry. As can be seen in  FIGS.  37 A,  37 B,  38 , and  39   , SDN controller (e.g., endpoint device  210 ) is configured to create match table entries that are executed by the SAN switches  230  (e.g., Switches  1  and  2 ) and intervening router/switch, and the match table entries enable SDN executing on the SAN switches  230  and router/switch to perform TCL functions according to one or more embodiments. 
       FIG.  40    is a flowchart of a computer-implemented process  4000  for using an extension to match tables in software defined networking to manage storage area networks in accordance with one or more embodiments of the present invention. The computer-implemented process  4000  in  FIG.  40    can be implemented using SAN  200  discussed herein, along with computer system  100  and/or elements of computer system  100  shown in  FIG.  1   . Accordingly, the computer-implemented process  4000  will now be described with reference to figures. At block  4002 , a storage area network (SAN) switch  230  with and managed by a software defined networking (SDN) architecture is configured to receive at least one match table (e.g., depicted in memory  206 ), the at least one table comprising the SDN architecture and routing information. At block  4004 , SAN switch  230  is configured to route traffic over a SAN  200  using the routing information in the at least one match table. 
     The at least one match table contains extended fields in the SDN architecture applicable for the SAN  200 . The extended fields having been modified to a format for the SAN  200 . The at least one table comprises match table entries having the routing information in the SDN architecture applicable for use in SAN  200 . The controller (e.g., endpoint device  210 ) is configured to generate match table entries in the at least one table, the match table entries having the routing information in the SDN architecture and being applicable for the SAN  200 . The SAN switch  230  is configured to receive the at least one table from the controller (e.g., endpoint device  210 ). The SAN switch  230  is configured to receive a frame (e.g., incoming traffic from a source endpoint device  210 ) having the SDN architecture, to match requested information in the frame to the routing information in the at least one table, and to use the at least one table to route the frame as the traffic over the SAN  200  (to a destination endpoint device  21 ). A controller (e.g., endpoint device  21 ) having the SDN architecture is configured to generate the at least one match table. 
     It is to be understood that although this disclosure includes a detailed description on cloud computing, implementation of the teachings recited herein are not limited to a cloud computing environment. Rather, embodiments of the present invention are capable of being implemented in conjunction with any other type of computing environment now known or later developed. 
     Cloud computing is a model of service delivery for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, network bandwidth, servers, processing, memory, storage, applications, virtual machines, and services) that can be rapidly provisioned and released with minimal management effort or interaction with a provider of the service. This cloud model may include at least five characteristics, at least three service models, and at least four deployment models. 
     Characteristics are as follows: 
     On-demand self-service: a cloud consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with the service&#39;s provider. 
     Broad network access: capabilities are available over a network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs). 
     Resource pooling: the provider&#39;s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to demand. There is a sense of location independence in that the consumer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). 
     Rapid elasticity: capabilities can be rapidly and elastically provisioned, in some cases automatically, to quickly scale out and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time. 
     Measured service: cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service. 
     Service Models are as follows: 
     Software as a Service (SaaS): the capability provided to the consumer is to use the provider&#39;s applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web-based e-mail). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings. 
     Platform as a Service (PaaS): the capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including networks, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations. 
     Infrastructure as a Service (IaaS): the capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls). 
     Deployment Models are as follows: 
     Private cloud: the cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on-premises or off-premises. 
     Community cloud: the cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on-premises or off-premises. 
     Public cloud: the cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services. 
     Hybrid cloud: the cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds). 
     A cloud computing environment is service oriented with a focus on statelessness, low coupling, modularity, and semantic interoperability. At the heart of cloud computing is an infrastructure that includes a network of interconnected nodes. 
     Referring now to  FIG.  41   , illustrative cloud computing environment  50  is depicted. As shown, cloud computing environment  50  includes one or more cloud computing nodes  10  with which local computing devices used by cloud consumers, such as, for example, personal digital assistant (PDA) or cellular telephone  54 A, desktop computer  54 B, laptop computer  54 C, and/or automobile computer system  54 N may communicate. Nodes  10  may communicate with one another. They may be grouped (not shown) physically or virtually, in one or more networks, such as Private, Community, Public, or Hybrid clouds as described herein above, or a combination thereof. This allows cloud computing environment  50  to offer infrastructure, platforms and/or software as services for which a cloud consumer does not need to maintain resources on a local computing device. It is understood that the types of computing devices  54 A-N shown in  FIG.  41    are intended to be illustrative only and that computing nodes  10  and cloud computing environment  50  can communicate with any type of computerized device over any type of network and/or network addressable connection (e.g., using a web browser). 
     Referring now to  FIG.  42   , a set of functional abstraction layers provided by cloud computing environment  50  ( FIG.  41   ) is shown. It should be understood in advance that the components, layers, and functions shown in  FIG.  42    are intended to be illustrative only and embodiments of the invention are not limited thereto. As depicted, the following layers and corresponding functions are provided: 
     Hardware and software layer  60  includes hardware and software components. Examples of hardware components include: mainframes  61 ; RISC (Reduced Instruction Set Computer) architecture based servers  62 ; servers  63 ; blade servers  64 ; storage devices  65 ; and networks and networking components  66 . In some embodiments, software components include network application server software  67  and database software  68 . 
     Virtualization layer  70  provides an abstraction layer from which the following examples of virtual entities may be provided: virtual servers  71 ; virtual storage  72 ; virtual networks  73 , including virtual private networks; virtual applications and operating systems  74 ; and virtual clients  75 . 
     In one example, management layer  80  may provide the functions described below. Resource provisioning  81  provides dynamic procurement of computing resources and other resources that are utilized to perform tasks within the cloud computing environment. Metering and Pricing  82  provide cost tracking as resources are utilized within the cloud computing environment, and billing or invoicing for consumption of these resources. In one example, these resources may include application software licenses. Security provides identity verification for cloud consumers and tasks, as well as protection for data and other resources. User portal  83  provides access to the cloud computing environment for consumers and system administrators. Service level management  84  provides cloud computing resource allocation and management such that required service levels are met. Service Level Agreement (SLA) planning and fulfillment  85  provide pre-arrangement for, and procurement of, cloud computing resources for which a future requirement is anticipated in accordance with an SLA. 
     Workloads layer  90  provides examples of functionality for which the cloud computing environment may be utilized. Examples of workloads and functions which may be provided from this layer include: mapping and navigation  91 ; software development and lifecycle management  92 ; virtual classroom education delivery  93 ; data analytics processing  94 ; transaction processing  95 ; and software applications (e.g., software applications  204  of SDN SAN switches  230 , one or more software applications  220  in SDN controllers, etc.) implemented in workloads and functions  96 . Also, software applications can function with and/or be integrated with Resource provisioning  81 . 
     Various embodiments of the invention are described herein with reference to the related drawings. Alternative embodiments of the invention can be devised without departing from the scope of this invention. Various connections and positional relationships (e.g., over, below, adjacent, etc.) are set forth between elements in the following description and in the drawings. These connections and/or positional relationships, unless specified otherwise, can be direct or indirect, and the present invention is not intended to be limiting in this respect. Accordingly, a coupling of entities can refer to either a direct or an indirect coupling, and a positional relationship between entities can be a direct or indirect positional relationship. Moreover, the various tasks and process steps described herein can be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. 
     One or more of the methods described herein can be implemented with any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc. 
     For the sake of brevity, conventional techniques related to making and using aspects of the invention may or may not be described in detail herein. In particular, various aspects of computing systems and specific computer programs to implement the various technical features described herein are well known. Accordingly, in the interest of brevity, many conventional implementation details are only mentioned briefly herein or are omitted entirely without providing the well-known system and/or process details. 
     In some embodiments, various functions or acts can take place at a given location and/or in connection with the operation of one or more apparatuses or systems. In some embodiments, a portion of a given function or act can be performed at a first device or location, and the remainder of the function or act can be performed at one or more additional devices or locations. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated. 
     The diagrams depicted herein are illustrative. There can be many variations to the diagram or the steps (or operations) described therein without departing from the spirit of the disclosure. For instance, the actions can be performed in a differing order or actions can be added, deleted or modified. Also, the term “coupled” describes having a signal path between two elements and does not imply a direct connection between the elements with no intervening elements/connections therebetween. All of these variations are considered a part of the present disclosure. 
     The following definitions and abbreviations are to be used for the interpretation of the claims and the specification. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains” or “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus. 
     Additionally, the term “exemplary” is used herein to mean “serving as an example, instance or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms “at least one” and “one or more” are understood to include any integer number greater than or equal to one, i.e. one, two, three, four, etc. The terms “a plurality” are understood to include any integer number greater than or equal to two, i.e. two, three, four, five, etc. The term “connection” can include both an indirect “connection” and a direct “connection.” 
     The terms “about,” “substantially,” “approximately,” and variations thereof, are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of ±8% or 5%, or 2% of a given value. 
     The present invention may be a system, a method, and/or a computer program product at any possible technical detail level of integration. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. 
     The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instruction by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
     Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments described herein.