ZyXEL Communications ADSL2+ Ethernet/USB Gateway 660RU-Tx Series - Manual (Page 269)

Prestige 660RU-Tx Series User’s Guide
Appendix D 268
Appendix D
PPPoE
PPPoE in Action
An ADSL modem bridges a PPP session over Ethernet (PPP over Ethernet, RFC 2516) from
your computer to an ATM PVC (Permanent Virtual Circuit) which connects to a DSL Access
Concentrator where the PPP session terminates (
see Figure 184 ). One PVC can support any
number of PPP sessions from your LAN. PPPoE provides access control and billing
functionality in a manner similar to dial-up services using PPP.
Benefits of PPPoE
PPPoE offers the following benefits:
It provides you with a familiar dial-up networking (DUN) user interface.
It lessens the burden on the carriers of provisioning virtual circuits all the way to the ISP on
multiple switches for thousands of users. For GSTN (PSTN and ISDN), the switching fabric
is already in place.
It allows the ISP to use the existing dial-up model to authenticate and (optionally) to provide
differentiated services.
Traditional Dial-up Scenario
The following diagram depicts a typical hardware configuration where the computers use
traditional dial-up networking.