.. rst-class:: unnumbered

Preface
=======

This specialized book is for the Ryu development framework, which is used to
achieve Software Defined Networking (SDN).

Why Ryu?

We hope you can find the answer in this book.

We recommend that you read Chapters ":ref:`ch_inst_guide`" to
":ref:`ch_spanning_tree`", in that order.
Chapter ":ref:`ch_inst_guide`" describes how to set up the environment for
this document, in Chapter ":ref:`ch_switching_hub`", we will implement a simple
switch hub application, and in later chapters, we will implement traffic
monitor and link aggregation functions to the simple switch hub application.
Through actual examples, we describe programming using Ryu.

Chapters ":ref:`ch_openflow_protocol`" to ":ref:`ch_of_config`" provide details
about the OpenFlow protocol and the packet libraries that are necessary for
programming using Ryu.
In Chapters ":ref:`ch_rest_firewall`" to ":ref:`ch_switch_test_tool`", we talk
about how to use the firewall and test tool included in the Ryu package as
sample applications.
Chapters ":ref:`ch_arch`" to ":ref:`ch_introduction_example`" introduce Ryu's
architecture and introduction cases.

Finally, we would like to say thank you to those people, in particular users,
who supported the Ryu project. We are waiting for your opinions via the mailing
list.

Let's develop Ryu together!