Overview
The NMC-RX application allows you to configure Broadband Remote Access Server (B-RAS) on your E-series device. The B-RAS application:
- Aggregates the output from digital subscriber line access multiplexers (DSLAMs)
- Provides user PPP sessions
- Provides PPP session termination
- Enforces quality of service (QoS) policies
- Routes traffic into an ISP's backbone network
A DSLAM collects data traffic from multiple subscribers into a centralized point so that it can be uploaded to your E-series device over an ATM connection through a DS3, an OC3, an E3, or an OC12 link.
The E-series device provides the logical termination for PPP sessions, as well as the interface to authentication and accounting systems.
B-RAS Protocol Support
Your E-series device supports the following protocols for B-RAS services for remote PPP clients:
- PPP
- PPP over Ethernet (PPPoE)
- Bridged Ethernet
- Layer 2 Tunneling Protocol (L2TP): L2TP access concentrator (LAC) and L2TP network server (LNS)
- Layer 2 Forwarding (L2F)
B-RAS Data Flow
The E-series device performs several tasks for a digital subscriber line (DSL) PPP user to establish a PPP connection:
- Authenticates the subscriber through RADIUS authentication
- Assigns an IP address to the PPP/IP session through RADIUS, local address pools, or DHCP
- Terminates the PPP encapsulation
- Provides user accounting by means of RADIUS
RADIUS
Remote Authentication Dial-In User Service (RADIUS) is a distributed client/server system that protects networks against unauthorized access. RADIUS clients running on an E-series device send authentication requests to a central RADIUS server. This server contains all the required user authentication and network access information.
You can configure RADIUS authentication and accounting services with the NMC-RX application. The authentication service determines that a user is allowed to access a specific service or resource. The accounting service tracks service use by subscribers.
DHCP
Dynamic Host Configuration Protocol (DHCP) provides a mechanism through which computers using TCP/IP can obtain protocol configuration parameters automatically from a DHCP server on the network.