[spp] [PATCH 1/5] docs: update overview section

[ogawa.yasufumi@lab.ntt.co.jp]

From: Yasufumi Ogawa <ogawa.yasufumi@lab.ntt.co.jp>

Some of contents of overview section is old and needd to be updated.
This patch is to update for the latest design of SPP controller which
is devided into front-end CLI and back-end server. It is also added
an explanation of OpenStack plugin `networking-spp`.

Signed-off-by: Yasufumi Ogawa <ogawa.yasufumi@lab.ntt.co.jp>
---
 docs/guides/overview.rst | 41 +++++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/docs/guides/overview.rst b/docs/guides/overview.rst
index 2529f77..386ac49 100644
--- a/docs/guides/overview.rst
+++ b/docs/guides/overview.rst
@@ -21,28 +21,41 @@ NFV (Network Function Virtualization).
 With SPP, user is able to configure network easily and dynamically
 via simple patch panel like interface.
 
-The goal of SPP is to easily interconnect DPDK applications together,
-and assign resources dynamically to these applications to build a
-pipeline.
+The goal of SPP is to easily interconnect NFV applications via high
+thoughput network interfaces provided by DPDK and change configurations
+of resources dynamically to applications to build pipelines.
+
 
 Design
 ------
 
-SPP is composed of a primary DPDK application that is
-responsible for resource management. This primary application doesn't
-interact with any traffic, and is used to manage creation and freeing of
-resources only.
+SPP is composed of several DPDK processes and controller processes [1].
+
+In terms of DPDK processes, SPP is derived from DPDK's multi-process sample
+application and it consists of a primary process and multiple secondary
+processes.
+SPP primary process is responsible for resource management, for example, ports,
+mbufs or shared memory. On the other hand, secondary processes are working for
+tasks.
+
+SPP is controlled from python based management framework. It consists of
+front-end CLI and back-end server process.
+SPP's front-end CLI provides a patch panel like interface for users.
+This CLI process parses user input and sends request to the back-end via REST
+APIs. It means that the back-end server process accepts requests from other
+than CLI. It enables developers to implement control interface such as GUI, or
+plugin for other framework.
+`networking-spp
+<https://github.com/openstack/networking-spp>`_
+is a Neutron ML2 plugin for using SPP with OpenStack.
+By using networking-spp and doing some of extra tunings for optimization, you
+can deploy high-performance NFV services on OpenStack [2].
 
-A Python based management interface, SPP controller, is provided to
-control the primary
-DPDK application to create resources, which are then to be used by
-secondary applications.
-This management application provides a socket
-based interface for the primary and secondary DPDK applications to
-interface to the manager.
 
 Reference
 ---------
 
 * [1] `Implementation and Testing of Soft Patch Panel
   <https://dpdksummit.com/Archive/pdf/2017USA/Implementation%20and%20Testing%20of%20Soft%20Patch%20Panel.pdf>`_
+* [2] `Integrating OpenStack with DPDK for High Performance Applications
+  <https://www.openstack.org/summit/vancouver-2018/summit-schedule/events/20826>`_
-- 
2.13.1