Optical networks and the like (e.g., Dense Wave Division Multiplexing (DWDM), Optical Transport Network (OTN), Ethernet, and the like) at various layers are using distributed control planes and/or centralized controlled via Software Defined Networking (SDN). Control planes provide an automatic allocation of network resources in an end-to-end manner. Exemplary control planes may include Automatically Switched Optical Network (ASON) as defined in ITU-T G.8080/Y.1304, Architecture for the automatically switched optical network (ASON) (February 2005), the contents of which are herein incorporated by reference; Generalized Multi-Protocol Label Switching (GMPLS) Architecture as defined in IETF Request for Comments (RFC): 3945 (October 2004) and the like, the contents of which are herein incorporated by reference; Optical Signaling and Routing Protocol (OSRP) from Ciena Corporation which is an optical signaling and routing protocol similar to Private Network-to-Network Interface (PNNI) and Multi-Protocol Label Switching (MPLS); or any other type control plane for controlling network elements at multiple layers, and establishing connections among nodes. SDN is an emerging framework which includes a centralized control plane decoupled from the data plane. SDN provides the management of network services through abstraction of lower-level functionality. This is done by decoupling the system that makes decisions about where traffic is sent (the control plane) from the underlying systems that forward traffic to the selected destination (the data plane). SDN works with an SDN controller knowing a full network topology through configuration or through the use of a controller-based discovery process in a network. Also, the distributed nature of control planes can be used in combination with the centralized nature of SDN in a hybrid approach.
Control planes, SDN, etc. are configured to automate various network operating processes including service restoration, service establishment, etc. Note, the service restoration and service establishment are generally a similar procedure which involves path computation, such as through a Path Computation Element (PCE) or the like, following by implementing the computed path in the underlying hardware. Conventional path establishment can use various techniques and algorithms to determine paths, such as Shortest Path Tree (SPT), Dijkstra's algorithm, various adjacency algorithms, etc. Of note, conventional techniques do not utilize restoration or service establishment time as a factor in path computation. Rather, these conventional techniques focus on avoiding or minimizing crank-backs or redials and not on the actual establishment time. Adding or removing channels in the photonic layer (optical layer, Layer 0, etc.) is slow relative to adding or removing channels in higher layers such as OTN or the like. Specifically, in the photonic layer, optical links require power optimization to minimize impacts to in-service channels while other channels are added or removed. Photonic restoration time not only scales with the number of hops but also with the number of channels being restored to a specific link. Ideally when a wavelength is deleted from, or added onto an Optical Multiplexed Section (OMS), the time taken would be fixed or would grow linearly in some deterministic fashion. In reality, there are dependencies on the existing wavelength load.
USPTO Backgrounds
USPTO Backgrounds