If you've shut down Expedient and brought up FOAM, you may have FlowVisor slices that were created by Expedient which are now essentially orphaned. For each of those FV slices, its owner should create an OpenFlow v3 rspec (the format FOAM uses), and create a new sliver in FOAM. You can then verify that the new sliver looks right, manually delete their old sliver, and approve the new one.
Here's an example, of migrating the jbs15 and jbs16 slivers at BBN.
Check to see that the new slivers are there in FOAM, awaiting approval:
Identify the Expedient-created FV slices:
Approve the new FOAM slivers:
Slice Authority trust configuration
You may want to configure FOAM to trust user certificates signed by additional Slice Authorities. To do that, install the CA cert for the Slice Authority in a file in /opt/foam/etc/gcf-ca-certs, and then rebuild the nginx CA cert bundle and restart FOAM and nginx:
In particular, campus mesoscale deployments may want to trust the pgeni.gpolab.bbn.com SA; you can get the cert from http://www.pgeni.gpolab.bbn.com/ca-cert/pgeni.gpolab.bbn.com.pem.