ZyXEL Communications Intelligent Broadband Sharing Gateway P-324 - Manual (Page 246)

Prestige 324 Intelligent Broadband Sharing Gateway
2 PPPoE
Diagram 1 Single-PC per Modem Hardware Configuration
How PPPoE Works
The PPPoE driver makes the Ethernet appear as a serial link to the PC and the PC runs PPP over it, while
the modem bridges the Ethernet frames to the Access Concentrator (AC). Between the AC and an ISP, the
AC is acting as a L2TP (Layer 2 Tunneling Protocol) LAC (L2TP Access Concentrator) and tunnels the
PPP frames to the ISP. The L2TP tunnel is capable of carrying multiple PPP sessions.
With PPPoE, the VC (Virtual Circuit) is equivalent to the dial-up connection and is between the modem
and the AC, as opposed to all the way to the ISP. However, the PPP negotiation is between the PC and the
ISP.