Update yardstick framework architecture in userguide

JIRA: YARDSTICK-590

This patch update the yardstick framework architecture in the userguide,
also fix some rst grammar mistakes

Change-Id: I84e7c24b4cd936a01f4c191e9f530f15f9f711de
Signed-off-by: JingLu5 <lvjing5@huawei.com>
(cherry picked from commit 7150e6bc49098937edcac0fa9fa108329c74af4a)

1 files changed, 125 insertions, 0 deletions

diff --git a/docs/testing/user/userguide/08-vtc-overview.rst b/docs/testing/user/userguide/08-vtc-overview.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International
+.. License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) OPNFV, National Center of Scientific Research "Demokritos" and others.
+
+==========================
+Virtual Traffic Classifier
+==========================
+
+Abstract
+========
+
+.. _TNOVA: http://www.t-nova.eu/
+.. _TNOVAresults: http://www.t-nova.eu/results/
+.. _Yardstick: https://wiki.opnfv.org/yardstick
+
+This chapter provides an overview of the virtual Traffic Classifier, a
+contribution to OPNFV Yardstick_ from the EU Project TNOVA_.
+Additional documentation is available in TNOVAresults_.
+
+Overview
+========
+
+The virtual Traffic Classifier (:term:`VTC`) :term:`VNF`, comprises of a
+Virtual Network Function Component (:term:`VNFC`). The :term:`VNFC` contains
+both the Traffic Inspection module, and the Traffic forwarding module, needed
+to run the :term:`VNF`. The exploitation of Deep Packet Inspection
+(:term:`DPI`) methods for traffic classification is built around two basic
+assumptions:
+
+* third parties unaffiliated with either source or recipient are able to
+inspect each IP packet’s payload
+
+* the classifier knows the relevant syntax of each application’s packet
+payloads (protocol signatures, data patterns, etc.).
+
+The proposed :term:`DPI` based approach will only use an indicative, small
+number of the initial packets from each flow in order to identify the content
+and not inspect each packet.
+
+In this respect it follows the Packet Based per Flow State (term:`PBFS`). This
+method uses a table to track each session based on the 5-tuples (src address,
+dest address, src port,dest port, transport protocol) that is maintained for
+each flow.
+
+Concepts
+========
+
+* *Traffic Inspection*: The process of packet analysis and application
+identification of network traffic that passes through the :term:`VTC`.
+
+* *Traffic Forwarding*: The process of packet forwarding from an incoming
+network interface to a pre-defined outgoing network interface.
+
+* *Traffic Rule Application*: The process of packet tagging, based on a
+predefined set of rules. Packet tagging may include e.g. Type of Service
+(:term:`ToS`) field modification.
+
+Architecture
+============
+
+The Traffic Inspection module is the most computationally intensive component
+of the :term:`VNF`. It implements filtering and packet matching algorithms in
+order to support the enhanced traffic forwarding capability of the :term:`VNF`.
+The component supports a flow table (exploiting hashing algorithms for fast
+indexing of flows) and an inspection engine for traffic classification.
+
+The implementation used for these experiments exploits the nDPI library.
+The packet capturing mechanism is implemented using libpcap. When the
+:term:`DPI` engine identifies a new flow, the flow register is updated with the
+appropriate information and transmitted across the Traffic Forwarding module,
+which then applies any required policy updates.
+
+The Traffic Forwarding moudle is responsible for routing and packet forwarding.
+It accepts incoming network traffic, consults the flow table for classification
+information for each incoming flow and then applies pre-defined policies
+marking e.g. :term:`ToS`/Differentiated Services Code Point (:term:`DSCP`)
+multimedia traffic for Quality of Service (:term:`QoS`) enablement on the
+forwarded traffic.
+It is assumed that the traffic is forwarded using the default policy until it
+is identified and new policies are enforced.
+
+The expected response delay is considered to be negligible, as only a small
+number of packets are required to identify each flow.
+
+Graphical Overview
+==================
+
+.. code-block:: console
+
+  +----------------------------+
+  |                            |
+  | Virtual Traffic Classifier |
+  |                            |
+  |     Analysing/Forwarding   |
+  |        ------------>       |
+  |     ethA          ethB     |
+  |                            |
+  +----------------------------+
+       |              ^
+       |              |
+       v              |
+  +----------------------------+
+  |                            |
+  |     Virtual Switch         |
+  |                            |
+  +----------------------------+
+
+Install
+=======
+
+run the build.sh with root privileges
+
+Run
+===
+
+::
+
+    sudo ./pfbridge -a eth1 -b eth2
+
+
+Development Environment
+=======================
+
+Ubuntu 14.04 Ubuntu 16.04