Update overview & architecture section

Change-Id: Ic86fd611fa56e5c611c9fe7f3d50a2d0f80a27d3
diff --git a/overview/introduction.rst b/overview/introduction.rst
index 5c0ba52..5570e06 100644
--- a/overview/introduction.rst
+++ b/overview/introduction.rst
@@ -5,19 +5,25 @@
 SD-Core Introduction
 ====================
 
-The SD-Core™ project is a 4G/5G disaggregated mobile core optimized for public
-cloud deployment in concert with distributed edge clouds and is ideally suited
-for carrier and private enterprise 5G networks. It exposes standard 3GPP interfaces
-enabling use of SD-Core as a conventional mobile core. It is also available
-pre-integrated with an adapter (part of the Aether ROC subsystem) for those
-deploying it as a mobile core as-a-service solution.
+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.
 
-SD-Core is an integral component of Aether, ONF’s 5G Connected Edge platform for
-private mobile connectivity and edge cloud services. It can be rapidly deployed
-pre-integrated with Aether, as a standalone 5G/4G mobile core, or as control and
-dataplane (UPF) components integrated into custom designed solutions. This range
-of versatility makes the open source SD-Core platform ideally suited for the
-broadest range of use cases and deployment scenarios.
+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.
 
 SD-Core Overview
 ----------------
@@ -31,13 +37,29 @@
 .. 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 SD-Core user plane components running at each Aether Edge site.
+      site controls multiple user plane components running at each Aether Edge site.
 
 .. image:: ../_static/images/Sd-Core-Aether-Integral.jpg
   :width: 700px