cloud. Use of OpenStack tools to support the deployment of VNFs and their associated VMs. Integration with the ONAP platform to Automate the instantiation and configuration of EPC VNFs Monitor the VNF components Automate the recovery of VNF components thereby, significantly improving the in-service time. All VMs of virtual EPC VNFs are designed with either N + 1 or N + K redundancy to ensure the realization of the above benefits. Standalone single VM instances are very rare in the virtual EPC design. 14.4.2.2 Virtual Logical Platform Architecture and Design The logical architecture of the virtual EPC platform is very similar to its current physical counter- part, except that all the elements are now software systems deployed on common hardware. The elements in the virtual EPC platform logical architecture are shown in Figure 14.18. In this section, we shall discuss the virtualization of the elements (MME, HSS, PCRF, SAEGW, Proxy) shown in the figure. 14.4.2.2.1 S-GW and P-GW VNF Components SAEGW or System Architecture Evolution [2] Gateway elements combine Serving Gateway (S-GW) or PDN (Packet Data Network) Gateway (P-GW) functions in a logical network function. AT&T's current SAEGW has the potential to function as an S-GW-Only, P-GW-Only, or both. S-GW or P-GW elements are typically deployed in AT&T's LTE mobility networks. S-GW (Serving Gateway): The S-GW performs many functions while connecting to the e-NodeBs on the RAN network, and the Mobility Management Entities (MMEs) and P-GW elements on the mobility network. Details of these functions can be found in various 3GPP documents [8]. Below is a short summary of these functions: Anchor for inter e-NodeB handover Anchor for 3GPP-defined mobile core elements Lawful intercept Packet routing/forwarding Packet marking for transport (both uplink and downlink) User accounting and QCI (Quality of Service Class Identifier) granularity for inter- operator charging Building the Network of the Future Virtual EPC Architecture Application Functions Tools FWs & LBs HSS (HSS-