Where Are You From? The Shibboleth service that provides a mechanism for routing users from a resource on their Service Provider to their point of login (Handle Service). However, it is notionally assumed to be 'optional' in the Shibboleth specification, and can be implemented either by a service provider, or as a central service, perhaps by the federation provision body. It is directly analogous to the Home Domain Discovery Service in AthensDA, and the Athens implementation currently supports both the AthensDA and Shibboleth specifications.