...
In general the EISCAT community lacks information about federated identity management.
EGI
Being EGI an highly distributed infrastructure, with hundreds of service providers, the lack of scalable policies for the release of the attributes from the IdPs is definitely a show-stopper. With hundreds of user communities (thousands of users) and service providers, integrating potentially hundreds of IdPs with all the service providers would require an excessive amount of effort, if possible at all.
The use cases of EGI have technical requirements that require command line access and delegation capabilities, which are not extensively supported by all the AAI federations.
From an internal point of view, the main barrier is that a good fraction of the legacy software used for resource provisioning will never be ported to technologies dfifferent from X509, therefore credential translation is the only way to access those services.
EUDAT
The main barriers for a wider coverage of IdP federations among communities and service providers from the EUDAT point of view are the lack of technical knowledge and sometimes of resources. Also the bureaucracy involved in joining a federation as an IdP or an SP is considered a barrier based on the EUDAT experience.
D4Science
The main barriers to expand the integration with federated identity management are in some cases the lack of resources/funds and the bureaucracy overhead involved in joining a federation. It is not always clear, for all the use cases, if the benefits of joining a federation compensate the overhead.