..
   SPDX-FileCopyrightText: © 2020 Open Networking Foundation <support@opennetworking.org>
   SPDX-License-Identifier: Apache-2.0

Introduction
============

SD-Core™ is the Open Networking Foundation™ (ONF)’s open source, flexible, agile,
scalable, and configurable dual-mode 4G/5G mobile core network solution that enables a
cloud-based Connectivity-as-a-Service. SD-Core builds and enhances on ONF’s 4G Open
Mobile Evolved Core (OMEC)™ as well as the free5GC© core network platform to create a
dual-mode solution that supports LTE, 5G NSA and 5G SA services optimized for hybrid-cloud
environments.

Its centralized dual-mode mobile core control plane has been designed to control many UPFs
distributed across many edge clouds around the world. This makes SD-Core the ideal open
source platform to offer cloud-based Private 4G/5G connectivity services to enterprises
as an enabler for Industry 4.0 transformation.

SD-Core provides a rich set of APIs for runtime configurability of each of its services, as well
as supporting subscriber management via third party applications. These APIs provide
extensive telemetry capabilities that enable monitoring, logging, and alerts, with integrated
verification and closed-loop control solutions. With operator and customer facing portals,
SD-Core can be configured for dynamically programmable network slicing, subscriber, QoS
and policy management, providing precise access control for users, devices, data networks
and edge applications.

Overview
--------

    - Ensure only authenticated mobile devices have network access
    - Provides IP connectivity for data & voice services
    - Ensures connectivity adheres to QoS and network slice policies
    - Tracks user mobility to ensure uninterrupted service
    - Tracks subscriber usage

.. image:: ../_static/images/SD-Core-Overview.png
  :width: 700px

SD-Core uses OMEC and free5GC as baseline components, integrates the two for dual-mode operation, and provides
significant new functionality to optimize delivery of Connectivity-as-a-Service from the
hybrid cloud. It is of course also possible to use SD-Core to provide 4G-only, or 5G-only
connectivity using standard 3GPP interfaces.

In order to optimize for the hybrid cloud and to support emerging Industry 4.0 use cases,
SD-Core includes multiple user plane functions (UPFs) to handle different classes of
enterprise traffic:

    - A P4-based UPF offloads the packet processing and forwarding operations to a
      programmable edge fabric to achieve significant performance with much higher
      bandwidths, significantly lower latencies, and highly predictable very low jitter, albeit
      for a relatively modest number of devices/flows
    - A containerized, highly scalable solution provides high performance by leveraging
      acceleration technologies like DPDK.

SD-Core is an Integral Part of Aether
-------------------------------------

    - SD-Core is an integral component of Aether, ONF’s 5G Connected Edge platform for
      private mobile connectivity and edge cloud services.
    - SD-Core provides the 4G/5G connectivity and the SD-Core control plane at the central
      site controls multiple user plane components running at each Aether Edge site.

.. image:: ../_static/images/Sd-Core-Aether-Integral.jpg
  :width: 700px