Enterasys Networks Security Router X-PeditionTM - Manual (Page 314)

Features
13-2 Configuring ADSL
Figure 13-1 RFC Encapsulation Layers
PDU Encapsulation Choices
The XSR’s Protocol Data Unit (PDU) encapsulation choices are described and illustrated as
follows.
PPP over ATM
The XSR’s PPPoA option, as defined by RFC-2364, supports the following features. The router
includes an integrated PPPoA client which adds LLC/SNAP encapsulation to packets headed to
the DSLAM, and strips the same from packets headed to its interior networks.
PPPoA is invoked by the encapsulation ipoa command. As shown in Figure 13-2 , PPPoA
supports networks running:
• LLC-encapsulated PPP payload over an ATM PVC
• Virtual circuit multiplexed PPP payload over an ATM PVC
• Statically configured and negotiated IP addresses
• Magic Number LCP configuration option
PPPoE
(RFC-2516)
PPPoA
(RFC-2364)
Routed
IP
PPPoE
(RFC-2516)
PPPoA
(RFC-2364)
Routed
IP
IP
PPPoA
PPPoE PPPoE
PPPoA
ATM AAL5
ADSL Modem
VC Multiplexing (RFC-1483/RFC-2684) LLC/SNAP (RFC-1483/RFC-2684)
Ethernet MAC Ethernet MAC
Note: Your choosing the correct PPP encapsulation method depends on the Customer Premises
Equipment (CPE) support offered by your DSL provider.