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 one reference implementations of an
OpenFlow switch. This implementation has the following components:
- ofdatapath, which implements the flow table in user space.
- ofprotocol, a program that implements the secure channel
component of the reference switch.
- dpctl, a tool for configuring the switch.
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 ofprotocol 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.
- A regression suite that tests OpenFlow functionality, please
see regress/README.
- A Wireshark dissector that can decode the OpenFlow wire
protocol. Please see utilities/wireshark_dissectors/README.
For installation instructions, read INSTALL. Each userspace program
is also accompanied by a manpage.
What's NOT here?
----------------
The reference implementation no longer includes the Linux kernel module
or the NetFPGA implementation. The OpenFlow consortium intends to
release these separately from the reference design.
Platform support
----------------
Other than the 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 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
-------
Public discussion list: [email protected]
Direct e-mail: [email protected]
Web: http://openflowswitch.org/
