I am looking to create a tiered server structure for SSO authentication that spans multiple domains. None of the domains will be in the same forest nor will there be domain trusts established. However, the plan is that ADFS will be configured at each domain to allow trusted communication for user authentication.
I am very new to ADFS but I do have a test environment working with a top-level ADFS domain to a mock service provider (also ADFS). I would like to extend the setup so a "2nd-tier level" (or 3rd-tier, etc.) domain with ADFS can be connected to the top-level domain so a user can visit the portal page at the top-level but to use credentials at a domain at "level" and can be authenticated to the service provider.
I would like to know if AD and ADFS is the proper technology to use to accomplish this. And assuming so, if there are some resources I can be directed towards to help me set that up to get it to work. Or if AD and ADFS is not a technology that can accomplish this goal, what recommendations do the experts have?