...
In order to allow users from Identity Providers (IdP) to login and use your service, you might need to adapt your IdP Discovery Service (i.e. the service that lets a user choose from which organisation he is from). If the tool presenting the list of organisation IdPs is limited to only few federations, specific IdPs or if your service does not have a Discovery Service at all, you can have a look at chapter E. (“Use a Discovery Service that supports Interfederation”) of https://wiki.edugain.org/How_to_offer_a_service_in_eduGAIN. (anchor to update, E.)
Step 4: Inform existing Customers about eduGAIN Access
...