Patent Publication Number: US-2016232078-A1

Title: Software defined network ecosystem

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application 61/884,905, filed Sep. 30, 2013, which is incorporated by reference. 
    
    
     BACKGROUND 
     A software defined network (SDN) is a form of network virtualization in which the control plane (system that makes decisions that affect network traffic) is separated from the data plane (system that moves the network traffic) and implemented as software. The control plane refers to definition of how network traffic is handled (e.g., via protocols such as spanning tree, open shortest path first, border gateway protocol, etc.) in a network device. The data plane refers to the actual handling of the network traffic according to the control plane (e.g., using forwarding tables, routing tables, queues, etc.) in a network device. The control plane may be said to be distributed in a typical network where each network device includes a control plane and a data plane. Thus, in the event of network congestion, each network device may take corrective action largely independently of other network devices. However, in an SDN, network administrators can have programmable (e.g., centralized) control of network traffic without requiring physical access to the network&#39;s hardware devices. An ecosystem may refer to a system of interacting and/or interconnecting parts, such as in a business. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a system according to the present disclosure. 
         FIG. 2  is a diagram illustrating an example of a device according to the present disclosure. 
         FIG. 3  is a diagram illustrating an example of a software defined network (SDN) ecosystem according to the present disclosure. 
         FIG. 4  is a flow chart illustrating a method according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Software Defined Networking (SDN) is an emerging network architecture where network control is decoupled from forwarding and is directly programmable. This migration of control, formerly tightly bound in individual network devices, into accessible computing devices enables the underlying infrastructure to be abstracted for applications and network services, which can treat the network as a logical or virtual entity. 
     Existing SDN implementations may include a lack of a marketplace to sell and/or support SDN applications. As used herein, an SDN application refers to program instructions that can be installed on a network controller to provide and/or modify functionality to a new and/or existing SDN. Typically, the software that provides SDN functionality on an SDN controller is closed such that it cannot be altered by a user or party other than the developer of the software. Interested parties are not allowed to collaborate to customize or improve SDN functionality. Also, an ability for non-SDN-providers to develop SDN applications may be limited because the SDN provider may implement the SDN as a canned product (e.g., where the SDN provider provides and/or controls the software that manages the SDN). As such, some SDN implementations may be hindered by complexities such as legacy network human middleware (e.g., network administrators that are trained and knowledgeable about typical network structures and are not comfortable with SDNs). 
     In contrast, a number of examples of the present disclosure can provide an SDN ecosystem that facilitates programming SDNs to align with business goals. This SDN ecosystem can include a marketplace to facilitate sharing ideas and software developments. In accordance with examples of the present disclosure, an SDN ecosystem that integrates an SDN application store (e.g., SDN AppStore) with an SDN controller allows developers and application users to have quick and easy access to applications to be deployed onto the SDN controller. 
       FIG. 1  is a diagram illustrating an example of a system  100  according to the present disclosure. The system  100  can include a database  101 , a subsystem  102 , and/or a number of engines  103 ,  104 . As used herein, “a” or “a number of” something can refer to one or more such things. For example, “a number of widgets” can refer to one or more widgets. The subsystem can include the number of engines in communication with the database  101  via a communication link. The system  100  can include additional or fewer engines than illustrated to perform the various functions described herein. The system can represent software and/or hardware of a network controller (e.g., device  208  as referenced in  FIG. 2 , etc.). 
     The number of engines  103 ,  104  can include a combination of hardware and programming that is configured to perform a number of functions described herein (e.g., enable a user among a plurality of users to download a new software defined network (SDN) application into a development environment within an SDN ecosystem and simulate operation of the SDN application in a network environment, etc.). The programming can include program instructions (e.g., software, firmware, etc.) stored in a memory resource (e.g., computer readable medium (CRM), machine readable medium (MRM), etc.) as well as hard-wired program (e.g., logic). 
     The simulation engine  103  can include hardware and/or a combination of hardware and programming to enable a user among a plurality of users to download a new (e.g., not previously existing and/or available in an SDN application store available to the users) SDN application into a development environment within an SDN ecosystem and simulate operation of the new SDN application in a network environment. As discussed further herein, the SDN ecosystem can comprise a single architecture deployed across a data center network, a campus area network, and/or a plurality of branch networks. In some examples, the simulation engine  103  can provide a software development kit (SDK) to facilitate development, simulation, and validation of the new SDN application. 
     The SDN application store engine  104  can include hardware and/or a combination of hardware and programming to provide access to a plurality of SDN applications (e.g., including new SDN applications) to the plurality of users. In some examples, the SDN application store engine  104  can allow a first user of the plurality of users to develop a first SDN application to be added to the plurality of SDN applications in the SDN application store. Also, the SDN application store engine can allow a second user among the plurality of users to purchase a second SDN application among the plurality of SDN applications. For example, the second user can purchase the SDN application added to the plurality of SDN applications by the first user. In some examples, the SDN application store engine can allow a third user among the plurality of users to sell a third SDN application among the plurality of SDN applications. That is, users of the SDN ecosystem can develop, share, and/or purchase SDN applications provided by other users within the SDN ecosystem. 
     In some examples, the system  100  can include an interactive environment engine (not illustrated in  FIG. 1 ) to enable collaboration between the plurality of users to modify the plurality of SDN applications, wherein the plurality of users include a customer, a developer, and a business partner of a provider of the SDN ecosystem. 
     Each of the number of engines  103 ,  104  can include hardware and/or a combination of hardware and programming that can function as a corresponding module as described with respect to  FIG. 2 . For example, the simulation engine  103  can include hardware and/or a combination of hardware and programming that can function as the simulation module  213 . In another example, the SDN application store engine  104  can include hardware and/or a combination of hardware and programming that can function as the SDN application store module  214 . 
       FIG. 2  is a diagram illustrating an example of a device  208  (e.g., a network controller) according to the present disclosure. The device  208  can utilize software, hardware, firmware, and/or logic to perform a number of functions. 
     The device  208  can be a combination of hardware and program instructions configured to perform a number of functions (e.g., actions). The hardware, for example, can include a number of processing resources  209  and a number of memory resources  211  (e.g., CRM, MRM, database, etc.). The memory resources  211  can be internal and/or external to the device  208  (e.g., the device  208  can include internal memory resources and have access to external memory resources). The program instructions (e.g., machine-readable instructions (MRI)) can include instructions stored on the MRM to implement a particular function (e.g., an action such as provide access to a plurality of SDN applications to the plurality of users). The MRI can be executable by one or more of the processing resources  209 . The memory resources  211  can be coupled to the device  208  in a wired and/or wireless manner. For example, the memory resources  211  can be an internal memory, a portable memory, a portable disk, and/or a memory associated with another resource, e.g., enabling MRI to be transferred and/or executed across a network such as the Internet. 
     Memory resources  211  can be non-transitory and can include volatile and/or non-volatile memory. Volatile memory can include memory that depends upon power to store information, such as various types of dynamic random access memory (DRAM) among others. Non-volatile memory can include memory that does not depend upon power to store information. Examples of non-volatile memory can include solid state media such as flash memory, electrically erasable programmable read-only memory (EEPROM), phase change random access memory (PCRAM), magnetic memory such as a hard disk, tape drives, floppy disk, and/or tape memory, optical discs, digital versatile discs (DVD), Blu-ray discs (BD), compact discs (CD), and/or a solid state drive (SSD), etc., as well as other types of machine-readable media. 
     The processing resources  209  can be coupled to the memory resources  211  via a communication path  210 . The communication path  210  can be local or remote to the device  208 . Examples of a local communication path  210  can include an electronic bus internal to a machine, where the memory resources  211  are in communication with the processing resources  209  via the electronic bus. Examples of such electronic buses can include Industry Standard Architecture (ISA), Peripheral Component Interconnect (PCI), Advanced Technology Attachment (ATA), Small Computer System Interface (SCSI), Universal Serial Bus (USB), among other types of electronic buses and variants thereof. The communication path  210  can be such that the memory resources  211  are remote from the processing resources  209 , such as in a network connection between the memory resources  211  and the processing resources  209 . That is, the communication path  210  can be a network connection. Examples of such a network connection can include LAN, wide area network (WAN), PAN, and the Internet, among others. 
     As shown in  FIG. 2 , the MRI stored in the memory resources  211  can be segmented into a number of modules  213 ,  214  that when executed by the processing resources  209  can perform a number of functions. As used herein, a module includes a set of instructions included to perform a particular task or action. The number of modules  213 ,  214  can be sub-modules of other modules. For example, the simulation module  213  can be a sub-module of the module SDN application store module  214  and/or the simulation module  213  and the SDN application store module  214  can be contained within a single module. Furthermore, the number of modules  213 ,  214  can comprise individual modules separate and distinct from one another. Examples are not limited to the specific modules  213 ,  214  illustrated in  FIG. 2 . 
     The simulation module  213  can simulate, in an SDN ecosystem, operation of a new SDN application, in response to receiving the new SDN application from a user of the SDN ecosystem. Further, the simulation module  213  can provide, to a provider of the SDN ecosystem, results from the simulated operation of the new SDN application. 
     The SDN application store module  214  can provide, to a plurality of users of the SDN ecosystem, access to the new SDN application in response to the provider of the SDN ecosystem approving the new SDN application. For instance, the SDN application store module  214  can execute instructions to provide the users of the SDN ecosystem with access to the plurality of SDN applications, including new SDN applications, using an SDN application store. 
     In some examples, as discussed further herein, the SDN application store module  214  can execute instructions to install a purchased SDN application on an SDN controller of a user among the plurality of users, in response to the user selecting the purchased SDN application from the application store. For instance, the SDN application store module  214  can use a virtual application networks (VAN) SDN controller in the SDN ecosystem to install the purchased SDN application on an SDN controller of the user. 
       FIG. 3  is a diagram illustrating an example of a SDN ecosystem  320  according to the present disclosure. The SDN ecosystem  320  can include an SDN architecture  321 . The SDN architecture  321  can include application functionality  322 , control functionality  323 , and/or infrastructure  324 . Further, the application functionality  322  can include an SDN application store (e.g., SDN App Store)  325  and/or an SDN software development kit (SDK)  326 . The application functionality can include a virtual cloud  327 , load balancing  328 , unified communications and collaboration (UC&amp;C)  329 , security  330 , SDN applications  331 , and/or infrastructure control  332 . As illustrated in  FIG. 3 , the control functionality  323  can be provided by a network controller  333  (e.g., a virtual application networks (VAN) SDN controller). However, in some instances, an SDN application can be hosted by machines separate from the SDN controller. Also, as illustrated in  FIG. 3 , the infrastructure  324  can include a number of network devices  334  such as a number of switches  335  and/or a number of routers  336 . In some examples, the SDN ecosystem  320  can provide design implementation and support services  337 . 
     The SDN ecosystem  320  can include a network controller  333 . An SDN is a form of network virtualization in which the control plane is separated from the data plane and implemented in a software application. Network administrators can therefore have programmable centralized control of network traffic without requiring physical access to the network&#39;s hardware devices. The network controller  333  can be hardware and/or software. A hardware network controller  333  include a processing resource in communication with a memory resource. The memory resource can include instructions, executable by the processing resource to perform a number of functions described herein. In some examples, the network controller  333  can be a discrete device, such as a server. In some examples, the network controller  333  can be a distributed network controller, for example, such as a cloud-provided functionality. Also, the network controller  333  can be in communication with and/or have control over a number of network devices. 
     In some examples, a software network controller  333  can be a VAN SDN controller. The VAN SDN controller  333  can be offered as licensable software to provide centralized automation for an SDN and/or open application programming interfaces (APIs) to enable third-party SDN application development. The VAN SDN controller  333  can have an extensible, scalable, and/or resilient controller architecture that can provide simplified management, provisioning, and/or orchestration in the SDN architecture  321 . The VAN SDN controller  333  can help provide a federated network solution designed to provide unified automation of, and visibility into, physical and virtual data center networks, enabling business agility and improving business continuity. 
     An SDN ecosystem  320  can include a programmable network aligned to business applications. That is, the SDN ecosystem  320  can conform to a number of open standards to facilitate efficient use for different customers, partners, businesses, etc. In some examples, the SDN ecosystem  320  can be deployed across a data center network, a campus area network, and/or a branch network. Any combination of the data center network (or multiple data center networks), the campus area network (or multiple campus area networks), and the branch network (or multiple branch networks) can be included in the SDN ecosystem  320 . 
     An SDN application (e.g., SDN App)  331  can be program instructions (e.g., a Java program) that can be executed on the network controller  333  (e.g., as an Open Services Gateway initiative (OSGi) bundle using a Java SDK) or off the network controller  333  using an API implemented by the network controller  333  (e.g., a northbound interface that conceptualizes the lower level details such as data or functions). As used herein, OSGi refers to a specification for Java based frameworks for development and dynamic deployment of modular components and libraries of a system. Some OSGi implementations can include Equinox, Apache Felix, and/or Knopflerfish OSGi. On OSGi bundle can be a tightly coupled, dynamically loadable collection of classes, jars, and/or configuration files onto a Java framework implementation of the OSGi specification. 
     In some examples, SDN applications  331  can interact with the network devices  334  and/or virtual machines to incorporate new and/or additional functionalities into the SDN ecosystem  320 . For instance, the SDN ecosystem  320  can include an SDN application store  325  that provides access to SDN applications  331  that can be installed on a network controller  333  to provide and/or modify functionality to a new and/or existing SDN. Further, the SDN application store  325  can be used to collect and maintain SDN applications  331  (e.g., in categories such as SDN, security  330 , data center, virtual cloud  327 , load balancing  328 , UC&amp;C  329 , and infrastructure control  332 , among others). 
     A user (e.g., human or machine) of the SDN application store  325  can login to a network controller  333  and install SDN applications  331  from the SDN application store  325  on the network controller  333 . In some examples, the SDN application store  325  can be provided by a first entity that is distinct from an entity that owns and/or manages a particular SDN. For example, a supplier of SDN hardware (e.g., SDN network devices such as network controllers, switches, routers, etc.) and/or software can provide the SDN application store  325  for access by customers of the supplier. As such, the supplier, customers, and/or third parties can have access to the SDN application store  325 . Access to the SDN application store  325  can include access to develop, use, simulate, certify, validate, purchase, and/or sell SDN applications  331 , among other types of access. In some examples, users can collaborate to provide improvements to SDN applications  331 . For example, users may provide recommendations and/or comments on how to improve various SDN applications  331 . Additionally, users can browse and/or search for SDN applications  331  in the SDN application store  325 . 
     SDN applications  331  in the SDN application store  325  can be shared with all users or with subsets of users. For example, a particular user can have a private portal to the SDN application store  325  that allows the particular user to have access to SDN applications  331  that are shared with the particular user, but not with all users. Similarly, the SDN application store  325  can promote wider exposure and/or increased sales for user developed SDN applications  331  by allowing a larger audience to access the SDN applications  331 . In some examples, a provider of the SDN application store  325  (e.g., a provider of the front and back end infrastructure) may collect a portion of the sales recognized from the SDN application store  325 . 
     In some examples, access to the SDN application store  325  can be provided via a graphical user interface (GUI). The GUI can include a display of SDN applications  331  organized by category. For example, the SDN applications  331  can be displayed in the SDN application store  325  and on a GUI, and can be organized into categories such as cloud, data center, featured, management, monitoring and troubleshooting, orchestration, and/or security, among other categories. From the GUI, a user can select a number of SDN applications  331  and install them on the user&#39;s network controller  333  via the GUI. Also, users can provide ratings for the SDN applications  331  in the SDN application store  325  via the GUI. A rating can include a numerical, alphanumerical, and/or symbolic value representing the user&#39;s satisfaction with a particular SDN application. In some examples, the GUI can provide descriptions of the SDN applications  331  to help users determine whether a particular SDN application is appropriate for the user&#39;s SDN. 
     The SDN ecosystem  320  can include an overlay network and an underlay network. As used herein, an overlay network refers to a network that is built on an underlay network. Also, as used herein, an underlay network refers to a number of SDN enabled network devices such as switches and/or routers. Network devices in the underlay network can employ an open protocol. One example of an open protocol for SDN is OpenFlow. As used herein, OpenFlow refers to which is a communications protocol that provides access to a forwarding plane of a network device over a network. Some examples of the present disclosure can operate according to OpenFlow. However, examples are not so limited, and examples of the present disclosure can operate according to other SDN protocols, and/or a hybrid of an SDN protocol combined with “normal” (e.g., distributed control plane) networking protocols. In some examples, network devices (e.g., routers) in the underlay network can be enabled with network functions virtualization (NFV) to provide some network functions with generic servers rather than dedicated network devices. For example, a virtual services router (VSR) can be deployed in a data center, branch, and/or cloud environment and can offer branch services that are centralized (e.g., in the data center), with branch instances logically managed as if they were remote but rather hosted in the data center. A VSR can be a single-tenant virtualized software wide area network (WAN) router designed for multi-tenant, hosted public clouds and virtualized branch customer-premises equipment (CPE) deployments. A VSR can be a virtualized software router that can run on VMware and/or a hypervisor (e.g., a software program that manages multiple operating systems, or multiple instances of the same operating system, on a single computer system). In some examples, network devices in the underlay network can be configured to support an overlay network (e.g., overlay enabled). 
     The overlay network can employ an encapsulation protocol such as virtual extensible local area network (VXLAN) to run the overlay network on the underlay network (e.g., on a Layer 2 and/or Layer 3 infrastructure). VXLAN can facilitate a cloud computing environment while logically isolating applications and/or tenants that use a portion of the cloud computing environment. For example, each tenant can have its own logical network and network identification in the cloud computing environment with an extended virtual local area network (VLAN) addressing space provided by VXLAN. The overlay network can employ network virtualization using generic routing encapsulation (NVGRE) to tunnel Layer 2 packets over a Layer 3 network to alleviate scalability problems associated with the cloud computing environment. In some examples, the overlay network can provide a number of virtual machines. 
     As illustrated in  FIG. 3 , the SDN ecosystem  320  can include an SDN SDK  326  (e.g., an open SDN SDK) to facilitate development, simulation, certification and/or validation of SDN applications  331 . The SDN SDK  326  can be provided by executable instructions that can be downloaded and installed by a user and/or run remotely for use by the user. For example, the SDN SDK  326  can be provided as a virtual desktop infrastructure (VDI). A VDI can be a service that hosts user desktop environments on a remote server that can be accessed over a network using a remote display protocol. A connection brokering service can connect the user to a desktop session of the user so that the user can access the desktop of the user from any location without being constrained to a single device. 
     The SDN SDK  326  can include a development suite that includes APIs and documentation, a GUI framework, a VAN SDN controller  333 , and a developer guide and/or sample code to help developers of SDN applications  331  with a development framework to quickly create SDN applications  331  directly on the VAN SDN controller  333 . The SDN SDK  326  can include an API design model such as a representational state transfer (REST) API. REST can be an architectural style that abstracts architectural elements within a distributed hypermedia system that ignores the details of component implementation and protocol syntax in order to focus on the roles of components, the constraints upon interaction with other components, and interpretation of significant data elements. The SDN SDK  326  can include a RESTful API (e.g., a web API implemented using hypertext transfer protocol (HTTP) and REST principles as a collection of resources). 
     The SDN SDK  326  can include a simulation suite that allows users to download software directly into a development environment and simulate networks with network simulation modules (e.g., using modules that create a realistic virtual network, running real kernel, network device and application code, on a real or virtual machine to simulate how the SDN will respond to a particular SDN application before it is actually implemented live in the SDN). An example of a network simulation tool is Mininet. The SDN SDK  326  can include a certification and/or validation suite that can provide and/or perform a certification and/or validation test for SDN applications  331  to determine whether a particular application meets defined standards (e.g., set by a provider of the SDN ecosystem  320 ) so that SDN applications  331  can be given an indication of certification and/or validation for the comfort of users. Testing, certification and/or validation can provide investment protection to help ensure that a user&#39;s network infrastructure can support SDN applications  331  as they become available. In some examples, the SDN SDK  326  can include a community portal (e.g., a forum for users to share ideas) and/or a knowledge base to enable collaboration, including creation of private working groups, training, services, and support. 
     In some examples, the certification and/or validation suite can include an SDN virtual lab for testing SDN application functionality and interoperability across proprietary and/or open applications in a ready-made environment that simulates user conditions without requiring the user to have access to real network devices. The SDN virtual lab can be hosted in a cloud environment and can be accessible by a user (e.g., an application developer) to test an SDN application  331  with a set of shared network devices, such as switches, routers, and/or computing devices (e.g., a server) among other network devices. The virtual lab test can run on a set of real network devices and servers that are configured to be used in an isolated and protected configuration for the purpose of testing an SDN application  331 . In some examples, once a particular virtual lab is reserved by a user, it can be exclusively used by the user for the duration of testing. The virtual lab can present a GUI to the user to allow the user to create a network to test the SDN application  331 . 
     The SDN ecosystem  320  can include a number of modules to help users (e.g., information technology professionals, SDN application developers, etc.) to understand good practices for adopting and implementing an SDN. For example, the SDN ecosystem  320  can include a preparation module to help a user understand the user&#39;s network and how the SDN can be implemented. By way of example, the Open Flow protocol can be explained to the user and/or an introduction to the SDN SDK  326  can be provided. The SDN ecosystem  320  can include an engagement module that allows users to take SDN deployment courses and/or SDN development courses, among others. A user can have a service agreement with a provider of the SDN ecosystem  320  allowing the user to have access (e.g., via telephone, email, web interface, etc.) to explanations and clarifications of APIs, software documentation, sample SDN applications  331 , troubleshooting resources for SDN applications  331  and/or network controller  333 , development of workarounds, sharing best practices, knowledge, development expertise, and/or self-validation testing assistance, among others. Also, the SDN ecosystem  320  can include a delivery module that allows users and/or SDN applications  331  to earn certification and/or validation. In some examples, the delivery module can be used to deploy SDN applications  331  (e.g., to the SDN application store  325 ). 
     An example of an advantage of the SDN ecosystem  320  can be providing a user (e.g., a customer) with an ability to purchase, download, and/or install an SDN application  331  in one streamlined workflow. Developers and/or SDN application  331  users can have quick access to the SDN applications  331  to be dynamically deployed with very few inputs (e.g., clicks of a mouse and/or keyboard). By way of example, the user can use the SDN ecosystem  320  by downloading the network controller  333  (e.g., a VAN SDN controller) and/or the SDN SDK  326  and installing the same on a server. The user can login to the network controller  333  GUI to access the SDN application store  325  (e.g., a cloud-based store) using credentials identifying the user and/or access the SDN application store  325  from a browser outside the context of the network controller  333 . Once the user selects an SDN application  331  to be downloaded, the user can select a number of network controllers  333  to which the SDN application  331  should be downloaded. The user can initiate and/or monitor the progress of the number of downloads (e.g., via the GUI). Once the number of downloads are complete, the SDN application  331  can be deployed on the number of network controllers  333 . In some examples, the user can be provided with options to start and/or stop the SDN application  331  (e.g., via the GUI). Further, the SDN application store  325  can have the capability to push SDN applications  331  to selected network controllers  333  (e.g., using HTTP POST, which can be a request method supported by the HTTP for requesting a server to accept data enclosed in the request message body for storage). In some examples, the SDN application  331  can be compressed (e.g., in a zip format) and the network controller  333  can expose REST API to collect the SDN application  331  and unzip it to dynamically deploy an SDN application bundle. 
       FIG. 4  is a flow chart illustrating a method  440  according to the present disclosure. At  441 , the method  440  can include receiving a new SDN application from a first user of an SDN ecosystem. As used herein, a new SDN application refers to an SDN application not previously stored in the SDN application store in the SDN ecosystem. For instance, a new SDN application can include an SDN application that a user has developed, but that has not yet been approved by the provider of the SDN ecosystem. Similarly, a new SDN application can include an SDN application that a user is currently developing, but that is not yet completed (e.g., portions of the code for the SDN application have yet to be written and/or tested). In some examples, the user can develop the new SDN application with assistance from the SDN ecosystem. For instance, the SDN ecosystem (e.g., via the design implementation and support services module) can provide the user with sample code to assist in the development of the new SDN application. 
     At  442 , the method  440  can include simulating operation of the new SDN application in the SDN ecosystem, in response to receiving the new SDN application from a user among a plurality of users of the SDN ecosystem. For example, a user of the SDN ecosystem can develop a new SDN application and wish to provide other users access to the new SDN application via the SDN application store. Prior to providing access to the new SDN application, the user (e.g., developer) can deploy (e.g., execute) the new SDN application in a test environment within the SDN ecosystem. During the simulation, the user can test the new SDN application functionality and interoperability with other SDN applications. Similarly, the user can test the new SDN application to verify that it functions properly with a variety of network devices. 
     At  443 , the method  440  can include storing the new SDN application in the SDN application store in the SDN ecosystem in response to receiving approval of the simulated operation from a provider of the SDN ecosystem. For example, as described in relation to  FIG. 3 , a report and/or log can be generated from the simulated operation of the new SDN application. The report and/or log generated can be provided to the provider of the SDN ecosystem for review. The provider of the SDN ecosystem can review the report and/or log and reject or accept the new SDN application. In response to receiving approval (e.g., acceptance) of the new SDN application, the new SDN application can be stored in the SDN application store. 
     In response to storing the new SDN application in the SDN application store, other users may access the new SDN application. However, in some examples, access to the new SDN application can be provided to only a subset of the plurality of users of the SDN ecosystem. For example, only users meeting specified security requirements could access the new SDN application. In another example, only users identified by the developer and/or SDN provider as belonging to a particular group and/or network could have access to the new SDN application. Examples described herein are not limiting, however, and access to the new SDN application can be limited to a subset of the plurality of users of the SDN ecosystem in any manner. 
     In some examples, the method  440  can include providing certification for SDN applications in the SDN application store that satisfy standards defined by the provider of the SDN ecosystem. For example, as discussed in relation to  FIG. 3 , the SDN SDK can facilitate development, simulation, certification and/or validation of SDN applications. Certification and/or validation can indicate to users of the SDN ecosystem that the certified and/or validated SDN applications are of a particular quality. 
     At  444 , the method  440  can include installing an SDN controller on a server of a second user of the SDN ecosystem in response to receiving a request from the second user to access the SDN ecosystem. For example, a user can use the SDN ecosystem by downloading an SDN controller and SDN SDK and installing both on a server within his SDN. The user can then log into the SDN controller GUI in order to access the SDN application store using his credentials (e.g., identifying information provided to the user from the provider of the SDN ecosystem). In some examples, the user can access the SDN application store from a browser without having to log into the SDN controller GUI. 
     At  445 , the method  440  can include installing the new SDN application onto the SDN controller on the server of the second user in response to the user selecting the new SDN application for installation. For instance, once SDN applications, including new SDN applications, are available for users to access in the SDN application store, the SDN applications can be downloaded by users of the SDN ecosystem. Once the user selects a particular SDN application to be downloaded, and the user selects his SDN controller(s) to which the application needs to be downloaded, the SDN ecosystem can install the selected SDN application(s) onto the SDN controller(s) in the users&#39; SDN. The SDN ecosystem can monitor progress of the installation, and display such progress to the user, for instance, on a GUI. Once the download of the SDN application to the SDN controller(s) is complete, the SDN application will be deployed onto the controller(s), and the user can be provided with options to start and/or stop the downloaded SDN applications as desired. 
     In the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration how a number of examples of the disclosure can be practiced. These examples are described in sufficient detail to enable those of ordinary skill in the art to practice the examples of this disclosure, and it is to be understood that other examples can be used and that process, electrical, and/or structural changes can be made without departing from the scope of the present disclosure. 
     The figures herein follow a numbering convention in which the first digit corresponds to the drawing figure number and the remaining digits identify an element or component in the drawing. Elements shown in the various figures herein can be added, exchanged, and/or eliminated so as to provide a number of additional examples of the present disclosure. In addition, the proportion and the relative scale of the elements provided in the figures are intended to illustrate the examples of the present disclosure, and should not be taken in a limiting sense. 
     As used herein, “logic” is an alternative or additional processing resource to perform a particular action and/or function, etc., described herein, which includes hardware, e.g., various forms of transistor logic, application specific integrated circuits (ASICs), etc., as opposed to computer executable instructions, e.g., software firmware, etc., stored in memory and executable by a processor. 
     The above specification, examples and data provide a description of the method and applications, and use of the system and method of the present disclosure. Since many examples can be made without departing from the spirit and scope of the system and method of the present disclosure, this specification merely sets forth some of the many possible embodiment configurations and implementations.