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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 BBN, Wisconsin and Clemson each with a MyPLC compute resource.

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. Steps required to set up the 3 Sites OpenFlow experiment are detailed in this page:

  • Authentication and Omni tools configuration
  • Determine Resources Availability
  • Define Compute Resources RSpecs
  • Define OpenFlow Network Resources Rspecs
  • Create Slice and Request Resources
  • Run Experiment
  • Release Resources

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 Availability

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 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 MyPLC aggregates:
     ./src/ -a listresources -o            # generates rspec-myplc-gpolab-bbn-com-12346-.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.

Define 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="" 
        xsi:schemaLocation=" ">  
  <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>   

Define OpenFlow Network Resources Rspecs

The OF RSpecs used for this example assumes that the flowspace between the 3 sites is based on traffic type and port. This section has two parts which:

  • Walks through how to figure out the OF network path
  • Show RSpec defined as a result of the walkthrough

Determine OF network path

Frome the listresources output files (attached to this page) determined the sites DPIDs BBN FOAM - Aggregate URL


FOAM Clemson - Aggregate


FOAM NLR - Aggregate URL


FOAM Wisconsin - Aggregate URL


OpenFlow Rspecs for FOAM

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

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  
./src/ -a deletesliver 3sites-OF-Exp 
./src/ -a deletesliver 3sites-OF-Exp 

Email us with any questions and feedback on this page!