Broadband Remote Access Server

With Broadband Remote Access Server ( BRAS ) or Broadband PoP (Point of Presence) are called network elements of broadband networks such as DSL and UMTS. They are part of the network of an Internet Service Provider ( ISP) and feed the data traffic of the end-user connections to the backbone network.

One of the tasks of a BRAS include:

• Aggregation of traffic from the access points (usually DSLAMs )
• Termination of PPP sessions or IP over ATM sessions. A BRAS may terminate about 50,000 concurrent PPPoE sessions
• Enforcement of guarantees and limitations in the context of Quality of Service

In broadband networks, DSLAMs collect the data traffic of the connected site participants and guide him through an ATM or IP network ( the so-called concentrator or concentration of power ) to the BRAS further, which in this case as a DSL Access Concentrator (DSL -AC ) is called.

The BRAS is the logical endpoint of PPP sessions. It may be PPP over Ethernet ( PPPoE) or PPP over ATM ( PPPoA ) act. The BRAS is thus responsible for the allocation of session parameters such as IP addresses. Therefore, the rear is connected to an authentication, authorization, and accounting system (AAA). Since it is a router, the BRAS the first visible hop between the client and the Internet.

The broadband network of Deutsche Telekom with 74 locations was initially set up with BRAS type ERX -1410 Juniper Networks and Cisco 6400, which were later replaced by ERX -1440. The VDSL network of Deutsche Telekom is built with the type BRAS Cisco 10008 and Ericsson SE800.

Recent Developments

The currently existing set of BRAS and DSLAM from the early days of networking, DSL is not really suitable for new services such as IPTV and IP telephony, as these services provide extended multicast and Quality of Service requirements. One possible solution is the realization of BRAS and DSLAM in a common unit.