1 OpenFlow Reference Release <http://openflowswitch.org>
6 OpenFlow is a flow-based switch specification designed to enable
7 researchers to run experiments in live networks. OpenFlow is based on a
8 simple Ethernet flow switch that exposes a standardized interface for
9 adding and removing flow entries.
11 An OpenFlow switch consists of three parts: (1) A "flow table" in
12 which each flow entry is associated with an action telling the switch
13 how to process the flow, (2) a "secure channel" connecting the switch
14 to a remote process (a controller), allowing commands and packets to
15 be sent between the controller and the switch, and (3) an OpenFlow
16 protocol implementation, providing an open and standard way for a
17 controller to talk to the switch.
19 An OpenFlow switch can thus serve as a simple datapath element that
20 forwards packets between ports according to flow actions defined by
21 the controller using OpenFlow commands. Example actions are:
23 - Forward this flow's packets to the given port(s)
24 - Drop this flow's packets
25 - Encapsulate and forward this flow's packets to the controller.
27 The OpenFlow switch is defined in detail in the OpenFlow switch
33 This distribution includes two reference implementations of an
34 OpenFlow switch. The first implementation, which is closely tied to
35 Linux because it is partially implemented in the Linux kernel, has the
38 - A Linux kernel module that implements the flow table and
39 OpenFlow protocol, in the datapath directory.
41 - secchan, a program that implements the secure channel
42 component of the reference switch.
44 - dpctl, a tool for configuring the kernel module.
46 The second implementation has the following components:
48 - udatapath, which implements the same functionality as the
49 Linux kernel module in userspace, at a cost in performance.
51 - secchan, a program that implements the secure channel
52 component of the reference switch (the same program used in
53 the kernel-based implementation).
55 This distribution includes some additional software as well:
57 - controller, a simple program that connects to any number of
58 OpenFlow switches, commanding them to act as regular MAC
61 - vlogconf, a utility that can adjust the logging levels of a
62 running secchan or controller.
64 - ofp-pki, a utility for creating and managing the public-key
65 infrastructure for OpenFlow switches.
67 - A patch to tcpdump that enables it to parse OpenFlow
70 For installation instructions, read INSTALL. Each userspace program
71 is also accompanied by a manpage.
76 Other than the Linux kernel module and userspace switch
77 implementation, the software in the OpenFlow distribution should
78 compile under Unix-like environments such as Linux, FreeBSD, Mac OS X,
79 and Solaris. Our primary test environment is Debian GNU/Linux.
80 Please contact us with portability-related bug reports or patches.
82 The Linux kernel module is, of course, Linux-specific, and the dpctl
83 utility will not be useful without the kernel module. The testing of
84 the kernel module has focused on Linux 2.6.26. Linux 2.6 releases
85 from 2.6.15 onward and Linux 2.4 releases from 2.4.20 onward should
88 The userspace datapath implementation should be easy to port to
89 Unix-like systems. The interface to network devices, in netdev.c, is
90 the code most likely to need changes. So far, only Linux is
91 supported. We welcome ports to other platforms.
93 GCC is the expected compiler.
98 - The flow table does not support the "normal processing" action.
103 [1] OpenFlow: Enabling Innovation in College Networks. Whitepaper.
104 <http://openflowswitch.org/documents/openflow-wp-latest.pdf>
106 [2] OpenFlow Switch Specification.
107 <http://openflowswitch.org/documents/openflow-spec-latest.pdf>
112 e-mail: info@openflowswitch.org
113 www: http://openflowswitch.org/