BRAS
full spelling ： Broadband Remote Access Server
A broad remote access server is a core item of an Internet service provider. It routes traffic to and from the digital subscriber line access multiplexers (DSLAM) on an Internet service provider's network.
BRAS provide more flexible service provisioning because subscriber services can be handled within a single managed network. BRAS provide an aggregation point for a variety of services. It is at the BRAS that an ISP can inject policy management and IP Quality of Service. The broadband remote access server is also the interface to authentication and authorization.