When looked at it by definition, RADIUS is one of the application layer protocols that takes its initials from the definition of "Remote Authentication Dial-in User Service". It uses the Network UDP protocol as a communication method. And it uses the Server / Client architecture.
Having High Availability High Scalability is important especially for the products offering solutions through SaaS infrastructure. Increase in the numbers of customers means more work for us, and if we don't build an infrastructure to lift his much work we would be wasting our sources.