Bob Lantz
21086cd79e
If we want to observe a monotonic affect, we should make sure that we are in fact CPU limited where it matters. In this case, we are CPU limiting the hosts, and the iperf client uses a lot of CPU. We need to reduce the CPU allocation so that iperf is in fact CPU bound. We also correct the CPU allocation so that the client and server each receive 50% of the total. Previously we were specifying the per-host CPU allocation, so 45% meant we were allocating 90% of the overall CPU, which seems a bit confusing. On the other hand, now at 40% each host gets 20% of the CPU, which could also be considered slightly confusing! Although the client transmit rate is going to be the limiting factor, we still measure the received data rate at the server, because that is more interesting than the initial burst of buffering at the client. Measuring at the server becomes more important as we reduce the iperf time. The output is also changed slightly, and the test has been updated appropriately.
Mininet: Rapid Prototyping for Software Defined Networks
The best way to emulate almost any network on your laptop!
Mininet 2.3.0d1
What is Mininet?
Mininet emulates a complete network of hosts, links, and switches on a single machine. To create a sample two-host, one-switch network, just run:
sudo mn
Mininet is useful for interactive development, testing, and demos, especially those using OpenFlow and SDN. OpenFlow-based network controllers prototyped in Mininet can usually be transferred to hardware with minimal changes for full line-rate execution.
How does it work?
Mininet creates virtual networks using process-based virtualization
and network namespaces - features that are available in recent Linux
kernels. In Mininet, hosts are emulated as bash processes running in
a network namespace, so any code that would normally run on a Linux
server (like a web server or client program) should run just fine
within a Mininet "Host". The Mininet "Host" will have its own private
network interface and can only see its own processes. Switches in
Mininet are software-based switches like Open vSwitch or the OpenFlow
reference switch. Links are virtual ethernet pairs, which live in the
Linux kernel and connect our emulated switches to emulated hosts
(processes).
Features
Mininet includes:
-
A command-line launcher (
mn) to instantiate networks. -
A handy Python API for creating networks of varying sizes and topologies.
-
Examples (in the
examples/directory) to help you get started. -
Full API documentation via Python
help()docstrings, as well as the ability to generate PDF/HTML documentation withmake doc. -
Parametrized topologies (
Toposubclasses) using the Mininet object. For example, a tree network may be created with the command:mn --topo tree,depth=2,fanout=3 -
A command-line interface (
CLIclass) which provides useful diagnostic commands (likeiperfandping), as well as the ability to run a command to a node. For example,mininet> h11 ifconfig -atells host h11 to run the command
ifconfig -a -
A "cleanup" command to get rid of junk (interfaces, processes, files in /tmp, etc.) which might be left around by Mininet or Linux. Try this if things stop working!
mn -c
New features in this release
This is primarily a performance improvement and bug fix release.
-
Batch startup has been implemented for Open vSwitch, improving startup performance.
-
OVS patch links have been implemented via OVSLink and --link ovs
Warning! These links have serious limitations compared to virtual Ethernet pairs: they are not attached to real Linux interfaces so you cannot use tcpdump or wireshark with them; they also cannot be used in long chains - we don't recommend more than 64 OVSLinks, for example --linear,64. However, they can offer significantly better performance than veth pairs, for certain configurations.
-
You can now easily install Mininet on a Raspberry Pi ;-)
-
Additional information for this release and previous releases may be found in the release notes on docs.mininet.org
Installation
See INSTALL for installation instructions and details.
Documentation
In addition to the API documentation (make doc), much useful
information, including a Mininet walkthrough and an introduction
to the Python API, is available on the
Mininet Web Site.
There is also a wiki which you are encouraged to read and to
contribute to, particularly the Frequently Asked Questions (FAQ.)
Support
Mininet is community-supported. We encourage you to join the
Mininet mailing list, mininet-discuss at:
https://mailman.stanford.edu/mailman/listinfo/mininet-discuss
Join Us
Thanks again to all of the Mininet contributors!
Mininet is an open source project and is currently hosted at https://github.com/mininet. You are encouraged to download the code, examine it, modify it, and submit bug reports, bug fixes, feature requests, new features and other issues and pull requests. Thanks to everyone who has contributed code to the Mininet project (see CONTRIBUTORS for more info!) It is because of everyone's hard work that Mininet continues to grow and improve.
Enjoy Mininet
Best wishes, and we look forward to seeing what you can do with Mininet to change the networking world!
Bob Lantz Mininet Core Team