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GENI OpenFlow Experiment Example 2

This page illustrates an OpenFlow (OF) example for the Omni How-to page. OpenFlow is used for the control of the network resources in the GENI backbone and at meso-scale campus locations. Experimenters can use these GENI resources without learning OpenFlow. The GPO can help arrange connectivity across your GENI slice, including IP connectivity and/or layer 2 VLANs.

For experimenters who desire control over the network switching fabric in their slices, OpenFlow provides increased flexibility. Your experiment will incorporate an OpenFlow controller. Many experimenters use existing controller code as-is, some use controllers with relatively simple modifications, and some experimenters have written their own controller. The GPO is available to help design your controller and plan your experiment configuration. Feel free to contact us at

The example captured in this page uses credentials from, the GPO ProtoGENI Clearinghouse, to set up an experiment that includes 3 meso-scale OpenFlow sites that include the following compute resources:

  • 1 PG compute resource at BBN running as a web server
  • 1 MyPLC compute resource at Wisconsin running as a web client
  • 1 MyPLC compute resource at Clemson running as a web client.

This example also shows a NOX OpenFlow Controller running on a slice resource that is available and accessible to the FOAM instances.

No image "OF-Experiment-example.jpg" attached to GENIExperimenter/ExperimentExample-OF-FOAM

Omni tools are used to reserve resources in each of the site's FlowVisor OpenFlow Aggregate Manager (FOAM) and GENI Aggregate Managers. All steps required to set up the Compute and Network Resources are outlined in this page:

  • Configure Omni tools
  • Define OpenFlow RSpecs for sites
  • Define OpenFlow RSpecs for GENI Core.
  • Define Compute Resources RSpecs for MyPLC and PG sites.
  • Request flowspace resources for sites and core.
  • Request compute resources from sites
  • Confirm connection
  • Run the experiment

Note: FOAM sites must be federated in order to trust a Clearinghouse. This is an OF administrator task that must take place before any of the user OF operations can take place.

Authentication and Omni tools configuration

This example assumes that GENI credentials have been set up as detailed in the GENI Credentials section of the Omni how-to page.

The following omni_config was used for this experiment along with the credentials from the GPO Clearinghouse to access the GENI Aggregate Managers in this experiment:

default_cf = pgeni
users = lnevers

# ---------- Users ----------
urn =
keys = ~/.ssh/

# ---------- Frameworks ----------
type = pg
ch =
sa =
cert = ~/.ssl/pgeni/encrypted-cleartext.pem
key = ~/.ssl/pgeni/encrypted-cleartext.pem

ch =
sa =
cert = ~/.ssl/protogeni/encrypted-cleartext.pem
key = ~/.ssl/protogeni/encrypted-cleartext.pem

A list of Aggregate managers is compiled in the GENI Aggregate page, if your site is not listed on this page you should contact your site administrator, or

Determine Resources

Each of the 3 sites will requires an OpenFlow RSpec and a compute resource RSpec. To find out what resources are available use Omni tools to get a list of available resources. FOllowing is a list of available GENI Aggregate Managers:

Site ProtoGENI Aggregate URL MyPLC Aggregate URL FOAM Aggregate URL
GA Tech

This experiment uses Omni V1.6.1 to set up the experiment. As a first step, the experimenter determines the available resources at each of the Aggregate Managers. Following are the omni commands issued to get the manifests for available resources:

  1. Clemson FOAM and MyPLC aggregates:
     ./src/ -a listresources -o   # generates output file rspec-foam-clemson-edu-3626-foam-gapi-1.xml
     ./src/ -a listresources -o            # generates rspec-myplc-clemson-edu-12346-.xml
  2. Wisconsin FOAM and MyPLC aggregates:
     ./src/ -a listresources -o    # generates rspec-foam-wail-wisc-edu-3626-foam-gapi-1.xml
     ./src/ -a  listresources -o # rspec-wings-openflow-1-wail-wisc-edu-12346-.xml
  3. BBN FOAM and PG aggregates:
     ./src/ -a listresources -o # generates rspec-www-pgeni-gpolab-bbn-com-protogeni.xml
     ./src/ -a listresources -o         # generates rspec-foam-gpolab-bbn-com-3626-foam-gapi-1.xml
  4. NLR OpenFlow Core FOAM server:
    $ ./src/ -a -o listresources           # generates rspec-foam-nlr-net-3626-foam-gapi-1.xml

Each of the omni command above used the -o argument to get the listresources output to a file, all output files are attached to this page as a reference. The Advertisement RSpec generated by the listresources are then reviewed to generate the Requests RSpecs to reserve the resources. Information in these files provides the switch and the port URN information to be used in making the OF flowspace reservation.

The above results will give you some insight into what is available, but it is recommended that you coordinate with the site contact to ensure RSpec accuracy for each of the OF Aggregate Managers.

Compute Resources RSpecs

The section shows the compute resources RSpec defined based on the output of the listresources commands.

BBN ProteGENI Compute Resource RSpec

<?xml version="1.0" ?>
<!-- Resources at AM:
        URN: unspecified_AM_URN
<rspec type="request" xmlns="" 
d ">  
  <node component_id="" 
        component_name="pc5" exclusive="true">    
      <sliver_type name="raw-pc">      

Clemson MyPLC Compute Resources RSpec

<?xml version="1.0" ?>
<!-- Resources at AM:
        URN: unspecified_AM_URN
<RSpec type="SFA">  
    <network name="plc">    
        <node component_id="" 
                node_id="n1" site_id="urn:publicid:IDN+plc:cu+authority+sa">    
            <hostname>      </hostname>      

Wisconsin MyPLC Compute Resources RSpec

<?xml version="1.0" ?>
<!-- Resources at AM:
        URN: unspecified_AM_URN
<RSpec type="SFA">  
    <network name="plc">    
        <node component_id="" 
                node_id="n9" site_id="urn:publicid:IDN+plc:wisc+authority+sa">  
            <hostname>      </hostname>   

OpenFlow Network Resources Rspecs

The OF RSpecs are used to request resources at each site's OpenFlow Aggregate Manager. This will result in your resource request being imported into the Opt-In manager, where an Administrator must approve your request for resources. Currently requesting OF resources for the sites in the experiment does not require OF setup for the Network Core path; the default handling will allow OF traffic. This is expected to change.

The OF RSpec defines a flowspace for each OF rule for your traffic sliver. Following are example OF RSpecs that could be used to reserve the flowspaces needed for each of the generic 3 node scenario in this page. The scenario uses 3 OF Aggregate Managers (one per site) and one OF Controller at Site 1 for all sites. The example RSpecs are for each of the 3 OF AM and assume that the flowspace is based on traffic type and port (TCP port 9080 and 9082).

BBN OpenFlow Network Resources RSpec

Clemson OpenFlow Network Resources RSpec

Wisconsin OpenFlow Network Resources RSpec

NLR OpenFlow Network Resources RSpec

Create Slice and Request Resources

Using the RSpecs that define the required OF flowspace, you can now request OF resources with Omni. First create a slice using your GPO Clearinghouse credentials as defined in the omni_config. Note that the slice name should be meaningful to you and then create a sliver for each resource aggregate. In this example there are 4 OF aggregates (one per site plus one for the GENI core) and 3 compute resource aggregates (1 PG & 2 MyPLC), which maps to creating 7 slivers, and the following commands are executed:

 ./src/ createslice 3sites-OF-Exp
./src/ -a createsliver 3sites-OF-Exp foam_bbn.rspec
./src/ -a createsliver 3sites-OF-Exp foam_indiana.rspec
./src/ -a createsliver 3sites-OF-Exp foam_internet2.rspec
./src/ -a createsliver 3sites-OF-Exp foam_nlr.rspec
./src/ -a createsliver  3sites-OF-Exp   myplc-clemson.rspec
./src/ -a createsliver 3sites-OF-Exp myplc-wisc.rspec
./src/ -a createsliver 3sites-OF-Exp pg-bbn.rpsec

Run Experiment

Once your flowspace has been opted in you should be able to exchange traffic over the approved flows between the hosts that have been allocated to your experiment. Simply SSH into one of the hosts and ping any of the other hosts to verify connectivity. If you have connectivity between the allocated hosts, you may start your experiment, if you do not have connectivity, contact

Remember to check the expiration time for the flowspace and for each aggregate with the Omni sliverstatus and to renewslice and renewsliver to expand the duration of the resource allocation to match your experiment needs. For an example on how to check sliverstatus and renewslice see the checking status section of the other non-OF experiment.

Release Resources

When the experiment is completed you should release the resources by deleting the sliver for each of the Resource Aggregates used in the Experiment. In the example experiment used in this page, the following commands should be issued to release resources:

./src/ -a deletesliver 3sites-OF-Exp
./src/ -a deletesliver 3sites-OF-Exp
./src/ -a deletesliver 3sites-OF-Exp
./src/ -a deletesliver 3sites-OF-Exp
./src/ -a deletesliver  3sites-OF-Exp   myplc-clemson.rspec
./src/ -a deletesliver 3sites-OF-Exp myplc-wisc.rspec
./src/ -a deletesliver 3sites-OF-Exp pg-bbn.rpsec

Email us with any questions and feedback on this page!