Broadband remote access server
A broadband remote access server (BRAS, B-RAS or BBRAS) routes traffic to and from broadband remote access devices such as digital subscriber line access multiplexers (DSLAM) on an Internet service provider's (ISP) network. BRAS can also be referred to as a broadband network gateway or border network gateway (BNG).
Source: Wikipedia — Broadband remote access server (CC BY-SA 4.0)