de servers for each function), to virtualized network functions hosted on general-purpose servers in the cloud. These virtualized core networks allow CSPs to expand into new services, such as cellular Internet of Things (IoT) or to provide enterprise-specific core services, or to refresh or expand legacy EPC networks. In practice, this virtualization of EPC does not work well in multivendor deployments as it was not built into the EPC specifications in the first place. Therefore, support for Network Function Virtualization and Software Defined Net- working was one of the first architecture requirements for the 5G core network. In addition, it was equally important to require capability for the 5G core network to be deployed in a cloud-native way. Applications designed for the cloud must also follow scaling design principles such as splitting the control plane and the user plane as well as separating compute and storage resources, capabilities which were not built into the EPC architecture. Separation of the control and user planes provides the ability to utilize distributed edge cloud architectures for bandwidth-intensive and latency-critical applications requiring independent distribution of the user plane functions from that of the control plane func- tions. For example, for certain low-latency use cases it will be important to place user 5.3 5G Core Network Architecture plane resources close to the access point where the user/device is attached, to reduce end-to-end latency and the transport network load. The 5G core network will further enable users to be connected simultaneously to the edge and central cloud and move between them. The core network needs to support stateless network functions where the compute resource is decoupled from the storage resource. Compute and storage separation enables unlimited linear scalability and extreme resilience. In the 5G architecture, the so-called Unified Data Management (UDM) will host subscriber data, session data, policies, operational data, charging, and accounting d