E-series routers use PPP over Ethernet (PPPoE) to enable multiple hosts to open PPP sessions to the router using one or more bridging modems. When service providers want to maintain the session abstraction associated with PPP, PPPoE is used with Broadband Remote Access Server (B-RAS) technologies that provide a bridged Ethernet topology. PPPoE can be configured over ATM or on Ethernet modules with or without VLANs.
Figure 33 shows how PPPoE allows the router to handle multiple PPP sessions originating on an Ethernet module to be multiplexed over one PVC on an ATM interface. PPP, as described in Configuring Point-to-Point Protocol, runs above the PPPoE layer.
Figure 33: PPPoE over ATM
The router handles the server part of PPPoE session management and never initiates a setup of a PPPoE session. The router only responds to session requests that are sent to it by the remote PPP client. After the sessions are set up, the router demultiplexes the sessions based on session identifiers assigned to a specific connection.
 | Copyright © 2008, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |