The term Access Registrar(AR) has several meanings. On the one hand, it is a component in broadband cable networks(BK), on the other hand, the term is used by Cisco for the Cisco Access Registrar( CAR).
The Cisco Access Registrar, on the other hand, is a AAA server for authentication, authorization, and accounting for the provider market. By centralizing AAA information, it supports service provider developments for access services and simplifies service provisioning and management. The CAR registrar is designed as a radius server or proxy server for high performance.