.. _opnfv-overview:

.. This work is licensed under a Creative Commons Attribution 4.0 International License.
.. SPDX-License-Identifier: CC-BY-4.0
.. (c) Open Platform for NFV Project, Inc. and its contributors

=================
Platform overview
=================

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

Network Functions Virtualization (NFV) is transforming the networking industry via
software-defined infrastructures and open source is the proven method for quickly developing
software for commercial products and services that can move markets.
Open Platform for NFV (OPNFV) facilitates the development and evolution of NFV
components across various open source ecosystems. Through system level integration,
deployment and testing, OPNFV constructs a reference NFV platform to accelerate the
transformation of enterprise and service provider networks.
As an open source project, OPNFV is uniquely positioned to bring together the work
of standards bodies, open source communities, service providers and commercial suppliers to deliver
a de facto NFV platform for the industry.

By integrating components from upstream projects, the community is able to conduct performance
and use case-based testing on a variety of solutions to ensure the platform’s suitability for
NFV use cases. OPNFV also works upstream with other open source communities to bring contributions
and learnings from its work directly to those communities in the form of blueprints, patches, bugs,
and new code.

OPNFV focuses on building NFV Infrastructure (NFVI) and Virtualised Infrastructure
Management (VIM) by integrating components from upstream projects such as OpenDaylight, ONOS, OpenContrail,
OVN, OpenStack, Kubernetes, Ceph Storage, KVM, Open vSwitch, and Linux.
More recently, OPNFV has extended its portfolio of forwarding solutions to include DPDK, fd.io and ODP,
is able to run on both Intel and ARM commercial and white-box hardware, support VM, Container and
BareMetal workloads, and includes Management and Network Orchestration MANO components primarily
for application composition and management in the Danube release.

These capabilities, along with application programmable interfaces (APIs) to other NFV
elements, form the basic infrastructure required for Virtualized Network Functions (VNF)
and MANO components.

Concentrating on these components while also considering proposed projects on additional
topics (such as the MANO components and applications themselves), OPNFV aims to enhance
NFV services by increasing performance and power efficiency improving reliability,
availability and serviceability, and delivering comprehensive platform instrumentation.


OPNFV Platform Architecture
===========================

The OPNFV project addresses a number of aspects in the development of a consistent virtualisation
platform including common hardware requirements, software architecture, MANO and applications.


OPNFV Platform Overview Diagram

.. image:: ../images/diagram_euphrates.png
   :alt: Overview infographic of the opnfv platform and projects.


To address these areas effectively, the OPNFV platform architecture can be decomposed
into the following basic building blocks:

* Hardware: Infrastructure working group, Pharos project and associated activities
* Software Platform: Platform integration and deployment projects
* MANO: MANO working group and associated projects
* Tooling and testing: Testing working group and test projects
* Applications: All other areas and drive requirements for OPNFV

OPNFV Lab Infrastructure
========================

The infrastructure working group oversees such topics as lab management, workflow,
definitions, metrics and tools for OPNFV infrastructure.

Fundamental to the WG is the
`Pharos Specification <https://wiki.opnfv.org/display/pharos/Pharos+Specification>`_
which provides a set of defined lab infrastructures over a geographically and technically
diverse federated global OPNFV lab.

Labs may instantiate bare-metal and virtual environments that are accessed remotely by the
community and used for OPNFV platform and feature development, build, deploy and testing.
No two labs are the same and the heterogeneity of the Pharos environment provides the ideal
platform for establishing hardware and software abstractions providing well understood
performance characteristics.

Community labs are hosted by OPNFV member companies on a voluntary basis.
The Linux Foundation also hosts an OPNFV lab that provides centralized CI
and other production resources which are linked to community labs.
Future lab capabilities will include the ability easily automate deploy and test of any
OPNFV install scenario in any lab environment as well as on a nested "lab as a service"
virtual infrastructure.

OPNFV Software Platform Architecture
====================================

The OPNFV software platform is comprised exclusively of open source implementations of
platform component pieces.  OPNFV is able to draw from the rich ecosystem of NFV related
technologies available in open source communities, and then integrate, test, measure and improve these
components in conjunction with our upstream communities.

---------------------------------
Virtual Infrastructure Management
---------------------------------

OPNFV derives it's virtual infrastructure management from one of our largest upstream ecosystems
OpenStack.  OpenStack provides a complete reference cloud management system and associated technologies.
While the OpenStack community sustains a broad set of projects, not all technologies are relevant in
the NFV domain, the OPNFV community consumes a sub-set of OpenStack projects and the usage and
composition may vary depending on the installer and scenario.

For details on the scenarios available in OPNFV and the specific composition of components
refer to the :ref:`OPNFV User Guide & Configuration Guide <opnfv-user-config>`.

OPNFV now also has initial support for containerized VNFs.

-----------------
Operating Systems
-----------------

OPNFV currently uses Linux on all target machines, this can include Ubuntu, Centos or SUSE Linux. The
specific version of Linux used for any deployment is documented in the installation guide.

Networking Technologies
=======================

---------------
SDN Controllers
---------------
OPNFV, as an NFV focused project, has a significant investment on networking technologies
and provides a broad variety of integrated open source reference solutions.  The diversity
of controllers able to be used in OPNFV is supported by a similarly diverse set of
forwarding technologies.

There are many SDN controllers available today relevant to virtual environments
where the OPNFV community supports and contributes to a number of these.  The controllers
being worked on by the community during this release of OPNFV include:

* Neutron: an OpenStack project to provide “network connectivity as a service” between
  interface devices (e.g., vNICs) managed by other OpenStack services (e.g. Nova).
* OpenDaylight: addresses multivendor, traditional and greenfield networks, establishing the
  industry’s de facto SDN platform and providing the foundation for networks of the future.
* OpenContrail: An open source SDN controller designed for cloud and NFV use cases. It has an
  analytics engine, well defined northbound REST APIs to configure and gather ops/analytics data.
* OVN: A virtual networking solution developed by the same team that created OVS. OVN stands for
  Open Virtual Networking and is dissimilar from the above projects in that it focuses only on overlay networks.

----------
Data Plane
----------
OPNFV extends Linux virtual networking capabilities by using virtual switching
and routing components. The OPNFV community proactively engages with the following open source
communities to address performance, scale and resiliency needs apparent in carrier
networks.

* OVS (Open vSwitch): a production quality, multilayer virtual switch designed to enable massive
  network automation through programmatic extension, while still supporting standard management interfaces and protocols.
* FD.io (Fast data - Input/Output): a high performance alternative to Open vSwitch, the core engine of
  FD.io is a vector processing engine (VPP). VPP processes a number of packets in parallel instead of one at
  a time thus significantly improving packet throughput.
* DPDK:  a set of libraries that bypass the kernel and provide polling mechanisms, instead of interrupt based operations,
  to speed up packet processing. DPDK works with both OVS and FD.io.

----
MANO
----
OPNFV integrates open source MANO projects for NFV orchestration and VNF management.
New MANO projects are constantly being added, currently OPNFV integrates:
* OpenBaton: Open Baton is a ETSI NFV compliant Management and Orchestration (MANO) Framework.
  It enables virtual Network Services deployments on top of heterogeneous NFV Infrastructures.
  OpenBaton is also used to deploy vIMS (clearwater and openIMS).


Deployment Architecture
=======================

A typical OPNFV deployment starts with three controller nodes running in a high availability
configuration including control plane components from OpenStack, SDN controllers, etc. and a minimum
of two compute nodes for deployment of workloads (VNFs).
A detailed description of the hardware requirements required to support the 5 node configuration
can be found in pharos specification: `Pharos Project <https://www.opnfv.org/developers/pharos>`_

In addition to the deployment on a highly available physical infrastructure, OPNFV can be
deployed for development and lab purposes in a virtual environment.  In this case each of the hosts
is provided by a virtual machine and allows control and workload placement using nested virtualization.

The initial deployment is done using a staging server, referred to as the "jumphost".
This server-either physical or virtual-is first installed with the installation program
that then installs OpenStack and other components on the controller nodes and compute nodes.
See the :ref:`OPNFV User Guide & Configuration Guide <opnfv-user-config>` for more details.


The OPNFV Testing Ecosystem
===========================

The OPNFV community has set out to address the needs of virtualization in the carrier
network and as such platform validation and measurements are a cornerstone to the
iterative releases and objectives.

To simplify the complex task of feature, component and platform validation and characterization
the testing community has established a fully automated method for addressing all key areas of
platform validation. This required the integration of a variety of testing frameworks in our CI
systems, real time and automated analysis of results, storage and publication of key facts for
each run as shown in the following diagram.

.. image:: ../images/OPNFV_testing_working_group.png
  :alt: Overview infographic of the OPNFV testing Ecosystem

Release Verification
====================

The OPNFV community relies on its testing community to establish release criteria for each OPNFV
release. With each release cycle the testing criteria become more stringent and better representative
of our feature and resiliency requirements. Each release establishes a set of deployment scenarios to validate,
the testing infrastructure and test suites need to accommodate these features and capabilities.

The release criteria as established by the testing teams include passing a set of test cases
derived from the functional testing project ‘functest,’ a set of test cases derived from our
platform system and performance test project ‘yardstick,’ and a selection of test cases for
feature capabilities derived from other test projects such as bottlenecks, vsperf, cperf and
storperf. The scenario needs to be able to be deployed, pass these tests, and be removed from
the infrastructure iteratively in order to fulfill the release criteria.

--------
Functest
--------
Functest provides a functional testing framework incorporating a number of test suites
and test cases that test and verify OPNFV platform functionality.
The scope of Functest and relevant test cases can be found in the :ref:`Functest User Guide <functest-userguide>`

Functest provides both feature project and component test suite integration, leveraging
OpenStack and SDN controllers testing frameworks to verify the key components of the OPNFV
platform are running successfully.

---------
Yardstick
---------
Yardstick is a testing project for verifying the infrastructure compliance when running VNF applications.
Yardstick benchmarks a number of characteristics and performance vectors on the infrastructure making it
a valuable pre-deployment NFVI testing tools.

Yardstick provides a flexible testing framework for launching other OPNFV testing projects.

There are two types of test cases in Yardstick:

* Yardstick generic test cases and OPNFV feature test cases;
  including basic characteristics benchmarking in compute/storage/network area.
* OPNFV feature test cases include basic telecom feature testing from OPNFV projects;
  for example nfv-kvm, sfc, ipv6, Parser, Availability and SDN VPN

System Evaluation and compliance testing
========================================

The OPNFV community is developing a set of test suites intended to evaluate a set of reference
behaviors and capabilities for NFV systems developed externally from the OPNFV ecosystem to
evaluate and measure their ability to provide the features and capabilities developed in the
OPNFV ecosystem.

The Dovetail project will provide a test framework and methodology able to be used on any NFV platform,
including an agreed set of test cases establishing an evaluation criteria for exercising
an OPNFV compatible system. The Dovetail project has begun establishing the test framework
and will provide a preliminary methodology for the Danube release. Work will continue to
develop these test cases to establish a stand alone compliance evaluation solution
in future releases.

Additional Testing
==================

Besides the test suites and cases for release verification, additional testing is performed to validate
specific features or characteristics of the OPNFV platform.
These testing framework and test cases may include some specific needs; such as extended measurements,
additional testing stimuli, or tests simulating environmental disturbances or failures.

These additional testing activities provide a more complete evaluation of the OPNFV platform.
Some of the projects focused on these testing areas include:

-----------
Bottlenecks
-----------
Bottlenecks provides a framework to find system limitations and bottlenecks, providing
root cause isolation capabilities to facilitate system evaluation.

--------
NFVBench
--------
NFVbench is a lightweight end-to-end dataplane benchmarking framework project.
It includes traffic generator(s) and measures a number of packet performance related metrics.

----
QTIP
----
QTIP boils down NFVI compute and storage performance into one single metric for easy comparison.
QTIP crunches these numbers based on five different categories of compute metrics and relies on
Storperf for storage metrics.

--------
Storperf
--------
Storperf measures the performance of external block storage. The goal of this project is
to provide a report based on SNIA’s (Storage Networking Industry Association) Performance Test Specification.

------
VSPERF
------
VSPERF provides an automated test-framework and comprehensive test suite for measuring data-plane
performance of the NFVI including switching technology, physical and virtual network interfaces.
The provided test cases with network topologies can be customized while also allowing individual
versions of Operating System, vSwitch and hypervisor to be specified.




.. _`OPNFV Configuration Guide`: `OPNFV User Guide & Configuration Guide`
.. _`OPNFV User Guide`: `OPNFV User Guide & Configuration Guide`
.. _`Dovetail project`: https://wiki.opnfv.org/display/dovetail
