Configuring Remote Access
The ERX system supports the following remote access functionality:
- Broadband Remote Access Server (B-RAS) - This application runs on the system and is responsible for:
- Aggregating the output from DSLAMs
- Providing user PPP sessions and PPP session termination
- Enforcing QoS policies
- Routing traffic into an ISP's backbone network
See ERX Broadband Access Configuration Guide, Chapter 1, Configuring Remote Access to the ERX System.
- Layer 2 Tunneling Protocol (L2TP) - A method of encapsulating layer 2 packets, such as PPP, for transmission across a network. In an L2TP relationship, an L2TP Access Concentrator (LAC) forms a client-server relationship with a destination, known as an L2TP Network Server (LNS), on a remote network.
You can configure the system to act as an LAC in PPP pass-through mode. The system creates tunnels dynamically by using AAA authentication parameters and transmits L2TP packets to the LNS through IP/UDP. See ERX Broadband Access Configuration Guide, Chapter 3, Configuring L2TP.
- Layer Two Forwarding (L2F) - A method that provides virtual dial-up service over the Internet. The traditional method for a remote user to access a company's network is through remote access equipment that is directly attached to the corporate network. This method requires a significant investment in equipment and support in addition to the cost of telephone charges for remote workers calling into the access equipment.
By employing L2F, an ISP can provide local access for the remote worker and forward the data traffic through a tunnel to the corporate network. This method allows a company to outsource the investment in remote access equipment to the ISP, while retaining full control over access to the corporate network. In particular, L2F allows leveraging multiple protocols and private addressing across the existing Internet infrastructure. See ERX Broadband Access Configuration Guide, Chapter 4, Configuring L2F.
- Non-PPP equal access - A method of allowing remote access in which the system provides IP addresses to subscribers' computers through Dynamic Host Configuration Protocol (DHCP). This method is particularly convenient for broadband (cable and DSL) environments or environments that use bridged Ethernet over ATM, because network operators can support one central system rather than an individual PPPoE client on each subscriber's computer. See ERX Broadband Access Configuration Guide, Chapter 6, Configuring DHCP Local Server.