+ OpenFlow Reference Release <http://openflowswitch.org>
+
+What is OpenFlow?
+-----------------
+
+OpenFlow is a flow-based switch specification designed to enable
+researchers to run experiments in live networks. OpenFlow is based on a
+simple Ethernet flow switch that exposes a standardized interface for
+adding and removing flow entries.
+
+An OpenFlow switch consists of three parts: (1) A "flow table" in
+which each flow entry is associated with an action telling the switch
+how to process the flow, (2) a "secure channel" connecting the switch
+to a remote process (a controller), allowing commands and packets to
+be sent between the controller and the switch, and (3) an OpenFlow
+protocol implementation, providing an open and standard way for a
+controller to talk to the switch.
+
+An OpenFlow switch can thus serve as a simple datapath element that
+forwards packets between ports according to flow actions defined by
+the controller using OpenFlow commands. Example actions are:
+
+ - Forward this flow's packets to the given port(s)
+ - Drop this flow's packets
+ - Encapsulate and forward this flow's packets to the controller.
+
+The OpenFlow switch is defined in detail in the OpenFlow switch
+Specification [2].
+
+What's here?
+------------
+
+This distribution includes two reference implementations of an
+OpenFlow switch. The first implementation, which is closely tied to
+Linux because it is partially implemented in the Linux kernel, has the
+following components:
+
+ - A Linux kernel module that implements the flow table and
+ OpenFlow protocol, in the datapath directory.
+
+ - secchan, a program that implements the secure channel
+ component of the reference switch.
+
+ - dpctl, a tool for configuring the kernel module.
+
+The second implementation has the following components:
+
+ - udatapath, which implements the same functionality as the
+ Linux kernel module in userspace, at a cost in performance.
+
+ - secchan, a program that implements the secure channel
+ component of the reference switch (the same program used in
+ the kernel-based implementation).
+
+This distribution includes some additional software as well:
+
+ - controller, a simple program that connects to any number of
+ OpenFlow switches, commanding them to act as regular MAC
+ learning switches.
+
+ - vlogconf, a utility that can adjust the logging levels of a
+ running secchan or controller.
+
+ - ofp-pki, a utility for creating and managing the public-key
+ infrastructure for OpenFlow switches.
+
+ - A patch to tcpdump that enables it to parse OpenFlow
+ messages.
+
+For installation instructions, read INSTALL. Each userspace program
+is also accompanied by a manpage.
+
+Platform support
+----------------
+
+Other than the Linux kernel module and userspace switch
+implementation, the software in the OpenFlow distribution should
+compile under Unix-like environments such as Linux, FreeBSD, Mac OS X,
+and Solaris. Our primary test environment is Debian GNU/Linux.
+Please contact us with portability-related bug reports or patches.
+
+The Linux kernel module is, of course, Linux-specific, and the dpctl
+utility will not be useful without the kernel module. The testing of
+the kernel module has focused on Linux 2.6.26. Linux 2.6 releases
+from 2.6.15 onward and Linux 2.4 releases from 2.4.20 onward should
+also work.
+
+The userspace datapath implementation should be easy to port to
+Unix-like systems. The interface to network devices, in netdev.c, is
+the code most likely to need changes. So far, only Linux is
+supported. We welcome ports to other platforms.
+
+GCC is the expected compiler.
+
+Bugs/Shortcomings
+-----------------
+
+- The flow table does not support the "normal processing" action.
+
+References
+----------
+
+ [1] OpenFlow: Enabling Innovation in College Networks. Whitepaper.
+ <http://openflowswitch.org/documents/openflow-wp-latest.pdf>
+
+ [2] OpenFlow Switch Specification.
+ <http://openflowswitch.org/documents/openflow-spec-latest.pdf>
+
+Contact
+-------
+
+e-mail: info@openflowswitch.org
+www: http://openflowswitch.org/