An Overview of RBFS C-BNG for IPoE Subscribers

This document provides guidance to validate IPoE implementation using the RBFS Consolidated BNG (C-BNG). The guide contains quick information about general platform configuration, configuration of various access and routing protocols, subscriber management, Quality of Service (QoS) and troubleshooting. The document presents a single use case scenario and provides information specifically on how to validate this particular implementation and for more information on any specific application, refer to https://documents.rtbrick.com/.

This guide is not intended to be an exhaustive guide of all RBFS features and does not provide information on features such as Multicast, Lawful Intercept etc.

About the RBFS Consolidated BNG

The RtBrick C-BNG is delivered as a container, running on Open Network Linux (ONL) provided by the hardware ODM manufacturers. Platforms that support C-BNG include Edgecore AGR 400, CSR 320, and UfiSpace S9600. The RtBrick C-BNG software runs on powerful bare-metal switches as an open BNG.

The BNG is designed to dynamically deliver the following services:

  1. Discovering and managing subscriber sessions for IPoE subscribers

  2. Providing authentication, authorization and accounting (AAA)

The basic C-BNG architecture for IPoE subscribers is shown in Fig. 1.

1000

Fig. 1: Topology setup with C-BNG as a DUT (device under test) connected to BNG Blaster.

In this topology:

  1. The Service Node is an Ubuntu server on which a new container is spawned with the associated interfaces for running BNG Blaster tests.

  2. BNG Blaster emulates both the routing and access functions. It is an open-source network tester developed by RtBrick to validate the performance and scalability of BNG devices. The BNG blaster can emulate both subscribers at scale and network elements such as routers. Therefore, it is possible to create complex topologies with just the DUT and a server that hosts the BNG Blaster, thereby minimizing the equipment needed to test the DU. For more information, refer to the BNG Blaster documentation. In this topology, BNG Blaster emulates IPoE (DHCP) subscribers. The Service Node runs BNG Blaster. To use BNG Blaster, download and install the BNG Blaster software onto the system that meets the tool’s system requirements. The software can be downloaded from https://github.com/rtbrick/bngblaster/releases.

  3. The topology emulates IPoE subscribers and traffic between RBFS switch and the core network.

  4. The objective of this topology is to demonstrate complete IPoE subscriber emulating and service along with routing to connect to the network uplink.

  5. R-1, R-2 and RR are simulated using BNG Blaster. The C-BNG forms an OSPF L1 adjacency with the BNG blaster to discover R-1, R-2, and RR. The RR is the route reflector that replays a full internet feed of IPv4 and IPv6 addresses, in total about 1.1 million prefixes. R-2 is the nexthop for all internet routes.

  6. Through DCHP, an IPv4 address needs to be assigned to the out-of-band management port.

Deployment

A C-BNG provides BNG functionality on a single bare-metal switch and eliminates the need to have a chassis-based system. It provides a low footprint and optimal power consumption based on BRCM chipsets, a compelling value proposition that has complete BNG and routing feature support.

C-BNG runs on small form-factor temperature-hardened hardware that allows deployments in street site cabinets.

The rtbrick-toolkit is a meta package that can be used to install all the tools needed to work with RBFS images (container or ONL installer) and the RBFS APIs.

For more information, see RBFS Installation Guide.

Using the RBFS CLI

Connect to the C-BNG node.

$ ssh <C-BNG-management-ip> -l supervisor
supervisor@<C-BNG-management-ip>'s password:

The password for C-BNG-management-ip should be entered here.

As a result, the CLI prompt will look like this:

supervisor@rtbrick>C-BNG.rtbrick.net:~ $

Open the RBFS CLI.

supervisor@rtbrick>C-BNG.rtbrick.net:~ $ cli

The CLI has three different modes:

  • operation mode is a read-only mode to inspect and analyse the system state

  • config mode allows modifying the RBFS configuration

  • debug mode provides advanced tools for trouble-shooting

The switch-mode command allows switching between the different modes. The show commands allow inspecting the system state. The set and delete commands, which are only available in the configuration mode, allow modifying or deleting the current configuration. The commit command persists the changes. RBFS provides a commit history which allows reviewing changes (show commit log) and restoring a previous configuration (rollback). There are also commands to ping destinations, capture network traffic, save the configuration to or load the configuration from a file.

The CLI supports abbreviating commands, provides suggestions by hitting the [tab] key and displays a context help by entering a ?.

For more information on how to use the RBFS CLI, see the RBFS CLI User Guide.