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
+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
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
+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:
- 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
+The OpenFlow switch is defined in detail in the OpenFlow switch
Specification [2].
What's here?
------------
-This distribution includes a Linux-specific reference implementation
-of an OpenFlow switch, comprising:
+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.
+ 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 connects to any number of
+ - 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
+ - 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
- A patch to tcpdump that enables it to parse OpenFlow
messages.
-For installation instructions, read INSTALL. This distribution also
-includes manpages for each of its userspace programs, in the man/
-directory.
+For installation instructions, read INSTALL. Each userspace program
+is also accompanied by a manpage.
Platform support
----------------
-Other than the Linux kernel module, 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.
+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 Linux kernel module is, of course, Linux-specific, and the secchan
-and dpctl utilities will not be as useful without the kernel module.
-The testing of the kernel module has focused on Linux 2.6.23. 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 current flowtable does not support all statistics messages
- mentioned in the Type 0 OpenFlow spec.
-
-- The flowtable does not support the "normal processing" action.
-
-- Configure/build system does not support separate build directory for
- the datapath. ./configure must be run from the source root.
-
-- dpctl dump-flows may freeze when large numbers of flows are in the
- flow table. This has no effect on the datapath.
+- The flow table does not support the "normal processing" action.
References
----------
[1] OpenFlow: Enabling Innovation in College Networks. Whitepaper.
- <http://openflowswitch.org/alpha/openflow-wp-v0.1.pdf>
+ <http://openflowswitch.org/documents/openflow-wp-latest.pdf>
[2] OpenFlow Switch Specification.
- <http://openflowswitch.org/alpha/openflow-spec-v0.2.pdf>
+ <http://openflowswitch.org/documents/openflow-spec-latest.pdf>
Contact
-------
git://git.onelab.eu / sliver-openvswitch.git / blobdiff