ecture, an SME is connected to the Internet via a lightweight CPE also called SDN-based CPE. Most features typically found on a CPE, such as NAT, DHCP, and a firewall/security gateway, are moved to VMs in the operator's cloud. The lightweight SDN-based CPE only retains the basic connectivity service, while being programmable via SDN. In the operator's cloud, VMs and physical resources (storage, compute) are configured via a cloud controller (CC), while network configuration is managed by an SDN controller. Finally, a moderator node/application provides a higher level of abstraction over the cloud and network controllers. Through the moderator, enterprises can select their desired services and configure service chaining policies. The enterprise's IT personnel can access the moderator through a secured dashboard with a user-friendly graphical interface. Figure 5.16 shows these components and their interactions, which are further described as follows. The customer portal: Through the customer portal, an enterprise administrator configures and manages enterprise policies, services, and network infrastructure. Each enterprise gets its own virtual infrastructure. VMs are launched for each enterprise and are not shared between enterprises. The first step is to register the vCPE Moderator Cloud controller SDN controiler Customer portal SDN-based Remote web IP edge Gateway servers vSwitch vSwitch vSwitch HyperV HyperV HyperV Figure 5.16 Virtualized CPE. 5.4 Virtualized Customer Premises Equipment along with its name, IP block, subnets, and SO on. Then, through the same portal, the enterprise specifies how the traffic should be mapped and steered across the VNFs (i.e., the service chaining policies). The moderator presents services and selected service chains to the enterprise customer, and abstracts away most details of resource allocation for VMs and network configuration. Each enterprise has a catalog of available services. Services can be deployed and chained in arbitrary order in both upstream and downstream direction