Applicability scenarios for Data Centres. Section 3.3 describes three possible deployment models and motivates the choice of the centralized model for the COSIGN DCN Control Plane, which is deployed at the DC operator domain with a single SDN controller. However, the adoption of this principle at the DC operator level, does not prevent its customers to deploy their own SDN controllers for operating their own virtual infrastructures. This option has been briefly mentioned for the VDC use-case in section 3.2, and it is further explained in the pictures below. Figure 9. Deployment for the use case on provisioning of overlay virtual networks. Figure 9 shows a typical deployment for the use case dedicated to the provisioning of overlay virtual networks. In this use case, the customer is interested only in a suitable environment to run its applications, independently on the specific topology of the virtual network infrastructures or the connectivity that allows the communication between the VMs. For this reason, the only SDN controller involved in this use case is the one which operates the DCN (SDN controller 1 in the picture). This controller is managed by the DC operator and provides the whole set of COSIGN Control Plane services: optical resource virtualization, optical infrastructure virtualization and provisioning of end-to-end connectivity, while upper layer SDN applications implement the overlay- based network virtualization which expose its services to the customer.
Applicability scenarios for Data Centres. Section 3.3 describes three possible deployment models and motivates the choice of the centralized model for the COSIGN DCN Control Plane, which is deployed at the DC operator domain with a single SDN controller. However, the adoption of this principle at the DC operator level, does not prevent its customers to deploy their own SDN controllers for operating their own virtual infrastructures. This option has been briefly mentioned for the VDC use case in Section 3.2, and it is further explained in the pictures below. Figure 9 – Deployment for the use case on provisioning of overlay virtual networks Figure 9 shows a typical deployment for the use case dedicated to the provisioning of overlay virtual networks. In this use case, the customer is interested only in a suitable environment to run its applications, independently on the specific topology of the virtual network infrastructures or the connectivity that allows the communication between the VMs. For this reason, the only SDN controller involved in this use case is the one which operates the DCN (SDN controller 1 in the picture). This controller is managed by the DC operator and provides the whole set of COSIGN Control Plane services: optical resource virtualization, optical infrastructure virtualization and provisioning of end-to-end connectivity, while upper layer SDN applications implement the overlay- based network virtualization which expose its services to the customer. Figure 10 – Deployment for the VDC use case On the other hand, in the VDC use case the customers are interested in a programmable virtual infrastructure which may be operated and configured using a dedicated control plane, external from the one which runs over the physical DCN. A possible solution to control this virtual infrastructure is to use again an SDN controller, resulting in a hierarchy with two levels of SDN controllers (see Figure 10). In this scenario, we can identify multiple trust domains. The first one is associated to the DC operator and corresponds to the SDN controller at the bottom (SDN controller 1 in the picture) which operates the DCN physical infrastructure. It implements the optical resource virtualization and offer the service for the on-demand provisioning of programmable virtual optical infrastructures. On top of that, N trust domains are associated to the tenants renting the virtual network slices. Each tenant deploys its own SDN controller (represented in green in the picture) to manage its network slice,...
