# Getting Started

## What's Ryu

Ryu is a component-based software defined networking framework.

Ryu provides software components with well defined API's that make it easy for developers to create new network management and control applications. Ryu supports various protocols for managing network devices, such as OpenFlow, Netconf, OF-config, etc. About OpenFlow, Ryu supports fully 1.0, 1.2, 1.3, 1.4, 1.5 and Nicira Extensions.

All of the code is freely available under the Apache 2.0 license. Ryu is fully written in Python.

## Quick Start

Installing Ryu is quite easy:

    % pip install ryu

If you prefer to install Ryu from the source code:

    % git clone git://github.com/osrg/ryu.git
    % cd ryu; pip install .

If you want to write your Ryu application, have a look at Writing ryu application document. After writing your application, just type:

    % ryu-manager yourapp.py

## Optional Requirements

Some functions of ryu require extra packages:

- OF-Config requires lxml and ncclient
- NETCONF requires paramiko
- BGP speaker (SSH console) requires paramiko
- Zebra protocol service (database) requires SQLAlchemy

If you want to use these functions, please install the requirements:

    % pip install -r tools/optional-requires

Please refer to tools/optional-requires for details.

## Prerequisites

If you got some error messages at the installation stage, please confirm dependencies for building the required Python packages.

On Ubuntu(16.04 LTS or later):

    % apt install gcc python-dev libffi-dev libssl-dev libxml2-dev libxslt1-dev zlib1g-dev

## Support

Ryu Official site is http://osrg.github.io/ryu/.

If you have any questions, suggestions, and patches, the mailing list is available at ryu-devel ML. The ML archive at Gmane is also available.