Abstract:
Method and systems for controlling a hybrid network having software-defined network (SDN) switches and legacy switches include initializing a hybrid network topology by retrieving information on a physical and virtual infrastructure of the hybrid network; generating a path between two nodes on the hybrid network based on the physical and virtual infrastructure of the hybrid network; generating a virtual local area network by issuing remote procedure call instructions to legacy switches in accordance with a network configuration request; and generating an SDN network slice by issuing SDN commands to SDN switches in accordance with the network configuration request.

Description:
RELATED APPLICATION INFORMATION 
       [0001]    This application claims priority to provisional application No. 61/864,077 filed Aug. 9, 2013, the contents thereof are incorporated herein by reference 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Network management has always been a big challenge in large-scale enterprise and datacenter environments. The network must operate reliably and provide high-performance connectivity while ensuring organizational policy management. This problem is further compounded by provisioning high-level guarantees such as network isolation across complex network boundaries and decoupling logical and physical network using network virtualization schemes. 
         [0003]    Software-Defined Networking (SDN) is a potential solution, providing great flexibility for fine-grained data plane control. Most existing work has provided network management solutions for a full deployment of SDN switches or a pure legacy switch deployment. However, monetary or practical constraints have made “hybrid networks” a reality. The term “hybrid networks” refers to systems, which are partially deployed using SDN switches and partially using legacy switches. 
         [0004]    Most existing solutions do not provide a management mechanism that can handle network management of hybrid systems. While hybrid topologies have been suggested, no adequate management solution exists. Additionally, while pure legacy network management and pure SDN management are well-studied fields, existing SDN controllers and legacy switch management mechanisms cannot be directly applied to hybrid network systems, as they will be unable to manage the legacy part of the system. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    A hybrid network controller that controls a network that has software-defined network (SDN) switches and legacy switches includes a user interface configured to display network information and to receive high-level network management commands; an SDN controller configured to communicate with the SDN switches to update and manage the SDN switches; a remote procedure call (RPC) manager configured to communicate with the legacy switches to update configuration and rules in the legacy switches; and a hybrid manager configured to a route between two communicating nodes in the network based on a network topology, to calculate legacy switches and SDN switches in the route to update, and to create a connection and network isolation using the RPC manager and SDN switch configuration. 
         [0006]    A method for controlling a hybrid network having software-defined network (SDN) switches and legacy switches include initializing a hybrid network topology by retrieving information on a physical and virtual infrastructure of the hybrid network; generating a path between two nodes on the hybrid network based on the physical and virtual infrastructure of the hybrid network; generating a virtual local area network by issuing remote procedure call instructions to legacy switches in accordance with a network configuration request; and generating an SDN network slice by issuing SDN commands to SDN switches in accordance with the network configuration request. 
         [0007]    These and other advantages of the invention will be apparent to those of ordinary skill in the art by reference to the following detailed description and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a diagram of a hybrid network architecture in accordance with the present principles. 
           [0009]      FIG. 2  is a block/flow diagram of a method for controlling a hybrid network in accordance with the present principles. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Embodiments of the present invention provide the design of a novel controller called “HybNET”, which leverages both software defined networking (SDN) and legacy network management to provide management interface, which is compatible with both SDN and legacy switches. The present embodiments employ the concept of “virtualization in virtualization,” which provides an overarching virtualized abstraction while virtualizing the intermediate connections using legacy switch as virtual links. In a virtualization in virtualization scheme, a virtual local area network (VLAN) is encapsulated inside an SDN slice. This provides the ability to manage the legacy part of the hybrid network using VLAN techniques, while the SDN slice sees the legacy part as a single virtual link, creating a slice that includes that virtual link between two switches. This makes the entire network virtualizable. 
         [0011]    This also provides for network isolation in the virtual links. Network isolation forms the core-basis of network virtualization as it isolates the traffic of one virtual network from other virtual networks. This allows network operators to provide an isolated view of the virtual network and apply operations with affecting other parts of the network. Isolation in virtual links is provided using virtual local area networking (VLAN) or other similar legacy network isolation techniques. Further, the present embodiments provide a centralized mechanism to automate the control and management of common network tasks (such as addition, deletion of Virtual networks, rule/flow updates, etc.). 
         [0012]    The present embodiments provide compatibility between heterogeneous network management schemes. In particular, they provide network virtualization with a novel toolset, which allows compatibility between existing network management mechanisms (using remote procedure calls (RPC) for legacy switches and controllers in SDN switches) so as to provide a network control and management tool for a “hybrid system.” 
         [0013]    Referring now to  FIG. 1 , an overview of a HybNet architecture is shown. A hybrid controller  102  provides a communication mechanism between SDN controller  104  and the hybrid network. The hybrid controller  102  allows the network operator  108  to send input and uses RPC calls to manage legacy network  106 . 
         [0014]    The SDN controller  104  allows network operators  108  to update flows and visualize and manage the network in SDN-enabled switches. The hybrid controller  102  communicates to the SDN controller  104  and commands it to update and manage the SDN portion of the network. For the legacy controller  106 , there are several mechanisms which may be used to manage legacy switches. In the present embodiments it is specifically envisioned that a simple RPC module may be used which accepts inputs and communicates with the hybrid controller  102  to manage legacy switches. 
         [0015]    The network operator  108  interacts with an interface module to view and manage the hybrid network. This allows the network operator  104  to handle higher-level intelligent tasks without worrying about the underlying technology to manage the physical topology  110 . The physical topology  110  can be described explicitly by the network operator  108  or can be discovered by the hybrid controller  102  using network protocols such as the link layer discovery protocol, but there may be technical constraints depending on the infrastructure. 
         [0016]    The hybrid controller  102  maintains the state of the entire network in a database  112  and updates the database  112  whenever any changes are made. The database  112  can also be used for persistent state management whenever the controller  112  is shut down. When the controller  102  is brought back up, the previous state can be retrieved in an initialization phase. 
         [0017]    Referring now to  FIG. 2 , a method of hybrid network management is shown. Block  202  starts up the hybrid controller  102 . If the hybrid controller  102  is a discrete hardware device, then this may represent powering the device on. Block  204  initializes the hybrid controller  102 . The first step of initialization is to retrieve the physical topology of the network in block  208 , whether by direct input from the network operator  104  or by automatic discovery in the hybrid controller  102 . Block  210  then retrieves the virtual infrastructure by, e.g., requesting the infrastructure information from database  112 . Block  210  recreates a mapping between the virtual/logical network and the physical network. Block  212  then generates a topology graph for the virtual topology following virtualization in virtualization. Block  214  performs setup of legacy components. For example, this may include legacy switch setup, which sets up trunk mode for all concerned ports and configures a management isolated VLAN. 
         [0018]    To ensure that a clean state of the hybrid system is maintained, block  206  determines whether there is any change in the physical network topology. If there is a change, block  207  updates the state in the database  112  and processing returns to block  204 . 
         [0019]    At block  220 , the hybrid controller  102  takes input from a user, e.g., the network operator  108 . This input represents some network management task. For example, the network operator  108  may request that the hybrid controller  102  add a virtual network. Block  222  then generates the shortest path between two communicating nodes on the virtual machine and determines which legacy switches need to he updated. The legacy switches act as virtual links and are updated by the hybrid controller  102 . The hybrid controller  102  is programmed to manage the SDN fabric, assuming the whole network to be SDN. 
         [0020]    Virtualization guarantees are updated by updating the VLAN table in each legacy switch and by using a sliceable switch application in SDN switches. A network ID is used to create a slice in the hybrid network, and each network ID maps to a VLAN legacy switch and an SDN slice. Block  224  generates the VLAN table, which includes using RPC requests in block  226  to update the legacy switches in advance by updating their VLAN tables. Update failures in any switch are recorded as a failure to generate the slice and all updates up to that point are rolled back. Block  228  generates the slice table, which includes configuring network slices using a sliceable switch app in the controller and updating the network slices when in-packed messages are received by the SDN controller in block  230 . 
         [0021]    Block  232  then updates the  112  database each time an update to the network has been successfully committed. Any partial failures are not committed and the system state is rolled back to the original. Processing returns to block  220  to wait for the next request. 
         [0022]    In large networks, cloud providers apply network isolation at layer  2  to guarantee user security and facilitate traffic management. For legacy switches, this may be accomplished by assigning a VLAN-ID to each user. For SDN switches, a sliceable switch application provides isolation guarantees. The hybrid controller  102  has a global view of the physical topology  110 . However, an SDN view network topology is provided to the SDN controller, while the legacy switches connecting SDN switches are interpreted as virtual links. The management of virtual links by the hybrid controller  102  ensures compatibility between SDN and the VLAN. 
         [0023]    Network intelligence tasks are therefore left to the SDN switches, while the legacy switches are limited to the task of packet transport (although such legacy switches may still have isolation capability). This ensures that the hybrid network retains some of the advantages and programmable flexibility of the SDN controllers  104 . The hybrid controller  102  acts as an interface, which can also provide some measure of control over the virtual links to ensure isolation using layer-2 VLAN mechanisms configured via RPC calls. 
         [0024]    The foregoing is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. Additional information is provided in Appendix A to the application. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that those skilled in the art may implement various modifications without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention.