 NFV insertion. Service Platforms Network Backbone IP Edge Router IP Edge Router Legacy IP Edge Routers Gateway Gateway Legacy Routers for Firewalled Access Switches SDN Local Admin Networks Controller New Clos Fabric Networks Legacy Routers vRouters for Internal Networks Network Integration Between the Physical and Virtual Data Centers FIGURE 14.20 Connectivity to legacy networks. interconnects between the legacy routers and the Clos fabric in the cloud. Routing policies are setup between the legacy and new routers in such a way that interconnects are only used for local legacy new traffic. 14.4.2.4 Capacity and Scaling Design The virtual EPC platform is deployed in multiple geographically diverse cloud locations. Each cloud location may consist of at least three OpenStack tenants: EPC tenant (VNFs: SAEGW, MSP traffic service, DNS, test tools, firewalls, load balanc- ers, and NAT) Support tenant (VNFs: PCRF and MSP management) Tools tenant (VNFs: tools server and test tools administration) There are typically one support and one tools tenant per cloud location. There can be multiple EPC tenants per cloud location. This stratification allows for better capacity management and scal- ing of the virtual EPC platform. Once an EPC instance reaches its maximum capacity, a new EPC instance is automatically instantiated, and activated. 14.4.2.4.1 Scalability The EPC platform is designed to scale VNFs independent of each other. The following VNFs all scale independently of other VNFs: 1. SAEGW (S-GW, P-GW and PCEF) 2. HTTP-proxy 3. PCRF 4. DNS 5. Firewalls and load balancers 6. Supporting tools In addition, components within each VNF can scale independently of other components in that VNF. This capability allows an instance of the EPC to react to business needs dynamically, with optimal utilization of data center resources. Building the Network of the Future VNF A VNF B VNF C VNF D VM Type 1 VM Type 1 VM Type 2 VM Type 3 VM Type 3 VM Type 1 VM Type 1 VM Type 1 VM Type 1 VM Type 1 VM Type 1 VM Type 2 VM Type 1 VM Type 1 In