Common use of Network Applications Clause in Contracts

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 SDN controller and, in case of unrecoverable failures, suitable notifications can be delivered towards the upper layers. Finally, a partial cross-layer visibility allows to re-program the whole underlying virtual paths taking into account the dynamicity of the overlay traffic, while informative services disclosing a suitable level of monitoring information about the DCN status and structure can be considered to take more efficient and network-aware decisions about the whole cloud service deployment. Cloud Service Orchestration (WP4) The Cloud Service Orchestration service, implemented in a cloud management platform like OpenStack, is the key entity for the integration between network and IT resources. The orchestrator manages the whole set of resources available in a Data Centre and relies on the DCN Control Plane for the configuration of the DCN and the provisioning of virtual network slices. The interaction between the cloud orchestrator and the DCN Control Plane is based on the REST API exposed at the A-CPI of the SDN controller and, optionally, can make use of REST APIs developed by SDN applications running on top of the controller itself. An example is the case of the Overlay-based Service Virtualization, which is implemented as an SDN controller and can be invoked by the cloud orchestrator to establish application-driven virtual overlay networks. However, the interaction between cloud orchestrator and DCN Control Plane in COSIGN is not only used to request actions of the DCN, but also to collect information about the DCN status or the existing network services already established on the DCN. This allows to bring a certain level of network awareness at the orchestrator level, that may be used to take more efficient decisions about IT resource allocations. Policy manager The Policy manager is a management application which allows the DCN administrator to configure and activate the policies that will be used within the SDN controller. These policies may regulate various aspects of the services offered by the SDN Control Plane, e.g. the level of disclosure that can exposed towards external entities regarding confidential information like topology, network performance, failures, etc. or the matching between abstract QoS parameters or application requirements and actual network configurations. AAA The AAA component offers functions for: - Authentication and authorization of SDN applications and tenants which operates on the DCN resources, directly or through virtual slices - Accounting for the usage of the DCN resources and the provisioning of virtual slices and optical connectivity. Accounting needs to support different charging and billing models, e.g. flat or pay-per-use. Accounting makes use of the services provided by the monitoring and statistics modules of the SDN controller. SLA manager The SLA manager is the entity in charge of configuring, enforcing and validating the SLAs established with the different tenants. It offers a management interface on the northbound to allow the DC administrator to configure the SLA and retrieve reports about SLA verifications. At runtime, it interacts with the provisioning manager for SLA enforcement and with the monitoring service for SLA assessment. It implements functions for detection of SLA violations and may also include algorithms for early SLA violation prediction or mechanisms to actively react in case of SLA failures.

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 SDN controller and, in case of unrecoverable failures, suitable notifications can be delivered towards the upper layers. Finally, a partial cross-layer visibility allows to re-program the whole underlying virtual paths taking into account the dynamicity of the overlay traffic, while informative services disclosing a suitable level of monitoring information about the DCN status and structure can be considered to take more efficient and network-aware decisions about the whole cloud service deployment. Cloud Service Orchestration (WP4) The Cloud Service Orchestration service, implemented in a cloud management platform like OpenStack, is the key entity for the integration between network and IT resources. The orchestrator manages the whole set of resources available in a Data Centre and relies on the DCN Control Plane for the configuration of the DCN and the provisioning of virtual network slices. The interaction between the cloud orchestrator and the DCN Control Plane is based on the REST API exposed at the A-CPI of the SDN controller and, optionally, can make use of REST APIs developed by SDN applications running on top of the controller itself. An example is the case of the Overlay-based Service Virtualization, which is implemented as an SDN controller and can be invoked by the cloud orchestrator to establish application-driven virtual overlay networks. However, the interaction between cloud orchestrator and DCN Control Plane in COSIGN is not only used to request actions of the DCN, but also to collect information about the DCN status or the existing network services already established on the DCN. This allows to bring a certain level of network awareness at the orchestrator level, that may be used to take more efficient decisions about IT resource allocations. Policy manager The Policy manager is a management application which allows the DCN administrator to configure and activate the policies that will be used within the SDN controller. These policies may regulate various aspects of the services offered by the SDN Control Plane, e.g. the level of disclosure that can exposed towards external entities regarding confidential information like topology, network performance, failures, etc. or the matching between abstract QoS parameters or application requirements and actual network configurations. AAA The AAA component offers functions for: - Authentication and authorization of SDN applications and tenants which operates on the DCN resources, directly or through virtual slices - Accounting for the usage of the DCN resources and the provisioning of virtual slices and optical connectivity. Accounting needs to support different charging and billing models, e.g. flat or pay-per-use. Accounting makes use of the services provided by the monitoring and statistics modules of the SDN controller. SLA manager The SLA manager is the entity in charge of configuring, enforcing and validating the SLAs established with the different tenants. It offers a management interface on the northbound to allow the DC administrator to configure the SLA and retrieve reports about SLA verifications. At runtime, it interacts with the provisioning manager for SLA enforcement and with the monitoring service for SLA assessment. It implements functions for detection of SLA violations and may also include algorithms for early SLA violation prediction or mechanisms to actively react in case of SLA failures.