Software defined networking systems and methods via a path computation and control element

#Generally, the field of art of the present disclosure pertains to networking systems and methods, and more particularly, to Software Defined Networking systems and methods via path computation and control.

#Automated connection control in optical or connection-oriented networks operates currently with fully distributed control, where requests for connections are made from the source node, either triggered by a client request (switched connection (SC)) or by management system (soft permanent connection (SPC)). A client request can utilize a standard user-network interface protocol such as have been defined in the Internet Engineering Task Force (IETF) or in the Optical Internetworking Forum (OIF), while management system interfaces are typically highly equipment dependent, as the management interface needs to be tailored to manage each device's unique set of characteristics.

#Path Computation Elements (PCEs) are described, for example, in RFC 4655 “A Path Computation Element (PCE)-Based Architecture,” (August 2006), the contents of which are incorporated by reference herein. This includes another standardized interface that has been defined for path computation, where the source node does not do its own path computation upon receiving a connection request (either SC or SPC) but makes a query to the centralized PCE. The Path Computation Client (PCC) requests a path to a specified destination with some constraints such as connection type or bandwidth, and the PCE responds with a list of nodes and links to be used, then the PCC creates the specified path using signaling. PCCs are also described, for example, in RFC 4655. The PCE was originally defined to be stateless, that is, having no memory retained after a path query has been received and responded to. A new extension to PCE now allows the PCE to retain state information, and in some cases affect the state of an established connection, for which the source node has previously delegated control to the PCE. This involves synchronization of the connection state between the PCC and PCE so that the PCE has an initial record of the connection state, then optionally delegation of state control from the PCC to the PCE, and then state updates from either side, from the PCC to reflect any events such as failures and from the PCE to reflect changes that it wants to make to the connection such as rerouting or deleting.

#Exemplary and non-limiting embodiments of the present disclosure are illustrated and described herein with reference to various drawings, in which like reference numbers denote like method steps and/or system components, respectively, and in which:

#FIGS. 1A-1B are network diagrams of a network with a client (FIG. 1A) and a management system (FIG. 1B) requesting connections;

#FIG. 2 is a network diagram of a network of network elements with a PCC requesting connections from a PCE;

#In various exemplary embodiments, the present disclosure relates to Software Defined Networking systems and methods via a Path Computation and Control Element (PCCE) that is based in part of a Path Computation Element (PCE). In the systems and methods described herein, a common, simple interface is designed based on an existing PCE interface, but allowing a centralized entity (i.e., a Path Computation and Control Element or PCCE) to control the initiation of new connections or tunnels, and by default also manage the state of these connections or tunnels once established. In particular, the systems and methods create an extension to the PCE architecture to allow a centralized application or applications to control the creation, rerouting and deletion of connections within a network. Compared to other mechanisms such as OpenFlow, the centralized controller (i.e., the PCCE) does not have to interact with each node in the connection (instead relying on the signaling intelligence in each node for distributed creation of the connection). Because it is based on PCE technology, it takes advantage of PCE infrastructure that has already been standardized, tested and implemented as an interface to network elements.

#Referring to FIGS. 1A-1B, in exemplary embodiments, network diagrams illustrate a network 10 with a client 12 (FIG. 1A) and a management system 14 (FIG. 1B) requesting connections. The network 10 includes a plurality of network elements 16 interconnected with one another. The network elements 16 can include, without limitation, optical network elements, switches, routers, cross-connects, etc. configured to use a control plane for management thereof. In an exemplary embodiment, the network elements 16 can include a nodal device that consolidates the functionality of a multi-service provisioning platform (MSPP), digital cross connect (DCS), Ethernet and Optical Transport Network (OTN) switch, dense wave division multiplexed (DWDM) platform, etc. into a single, high-capacity intelligent switching system providing Layer 0, 1, 2, and/or 3 consolidation. In another exemplary embodiment, the network elements 16 may include any of an OTN add/drop multiplexer (ADM), SONET/SDH ADM, a multi-service provisioning platform (MSPP), a digital cross-connect (DCS), an optical cross-connect, a WDM/DWDM terminal, a switch, a router, and the like.

#Generally, the control plane includes software, processes, algorithms, etc. that control configurable features of the network 10, such as automating discovery of the network elements 12, capacity on the links 14, port availability on the network elements 12, connectivity between ports; dissemination of topology and bandwidth information between the network elements; calculation and creation of paths for connections; network level protection and restoration; and the like. Exemplary control planes can include, without limitation, Automatically Switched Optical Network (ASON) as defined in inter alia G.8080/Y.1304, Architecture for the automatically switched optical network (ASON) (02/2005), the contents of which are herein incorporated by reference, and the like; Generalized Multi-Protocol Label Switching (GMPLS) Architecture as defined in inter alia Request for Comments: 3945 (10/2004), the contents of which are herein incorporated; Optical Signaling and Routing Protocol (OSRP) from Ciena Corporation which is an optical routing protocol similar to PNNI (Private Network-to-Network Interface) and MPLS (Multiprotocol Label Switching); and the like. Those of ordinary skill in the art will recognize the network 10 and the control plane may utilize any type of control plane for controlling the network elements 16 and establishing connections therebetween.