Network Applications Clause Samples

Network Applications. The COSIGN control plane architecture described here follows the SDN principle of keeping the SDN controller itself as a generalized container of basic network functions which aim to provide deep programmability of optical resources in the DCN for SDN applications and services running above the controller. The core network functions presented above provides all the tools and the primitives, i.e. through the A-CPI, to manage, control and operate the COSIGN optical DCN in a programmable and flexible way. A set of SDN applications are implemented over the COSIGN SDN controller, both at the COSIGN Control Plane (WP3) and at the cloud orchestrator level (WP4). These applications cover more complex control procedures, often involving also IT resources (e.g. joint provisioning of virtual network and IT infrastructures at the cloud orchestrator), or management functions that are needed to match the global COSIGN requirements. Example of these applications include the overlay-based network and service virtualization, the orchestration of cloud services (WP4) and management functions like policy configuration, accounting and billing, authentication and authorization or SLA management (see Table 4). Table 4 – SDN applications in COSIGN architecture SDN application Description Overlay-based service virtualization This is a key SDN application in the COSIGN architecture and it implements the highest level of network virtualization following the overlay-based model with traffic encapsulated at the end points and tunneled across the DCN. In particular, it does not need to have a direct view of the DCN topology and capabilities, but it can just rely on the abstract connection services provided by the infrastructure control layer, i.e. by the SDN controller A-CPI APIs. This approach simplifies the service virtualization approach, since it operates just at the network edges. On the other hand, the cooperation with the infrastructure control functions introduces a certain degree of awareness and mutual adaptation between the two layers, with the possibility to overcome the limitations of the pure overlay-based approach. For example, bandwidth constraints between two end points can be guaranteed through the proper configuration of optical connection paths at the infrastructure control layer, upon specific request of the service virtualization layer. Connection recovery can be also managed in a transparent and policy-driven way at the infrastructure control layer inside the SD...