ZyXEL Communications P-2612HW-F1 User Manual page 116

Chapter 6 WAN Setup
6.5.1.1 ENET ENCAP
The MAC Encapsulated Routing Link Protocol (ENET ENCAP) is only implemented
with the IP network protocol. IP packets are routed between the Ethernet interface
and the WAN interface and then formatted so that they can be understood in a
bridged environment. For instance, it encapsulates routed Ethernet frames into
bridged ATM cells. ENET ENCAP requires that you specify a gateway IP address in
the Gateway IP Address field in the wizard or WAN screen. You can get this
information from your ISP.
6.5.1.2 PPP over Ethernet
The ZyXEL Device supports PPPoE (Point-to-Point Protocol over Ethernet). PPPoE
is an IETF Draft standard (RFC 2516) specifying how a personal computer (PC)
interacts with a broadband modem (DSL, cable, wireless, and so on.) connection.
The PPPoE option is for a dial-up connection using PPPoE.
For the service provider, PPPoE offers an access and authentication method that
works with existing access control systems (for example RADIUS).
One of the benefits of PPPoE is the ability to let you access one of multiple network
services, a function known as dynamic service selection. This enables the service
provider to easily create and offer new IP services for individuals.
Operationally, PPPoE saves significant effort for both you and the ISP or carrier, as
it requires no specific configuration of the broadband modem at the customer site.
By implementing PPPoE directly on the ZyXEL Device (rather than individual
computers), the computers on the LAN do not need PPPoE software installed,
since the ZyXEL Device does that part of the task. Furthermore, with NAT, all of
the LANs' computers will have access.
6.5.1.3 PPPoA
PPPoA stands for Point to Point Protocol over ATM Adaptation Layer 5 (AAL5). A
PPPoA connection functions like a dial-up Internet connection. The ZyXEL Device
encapsulates the PPP session based on RFC1483 and sends it through an ATM PVC
(Permanent Virtual Circuit) to the Internet Service Provider's (ISP) DSLAM (Digital
Subscriber Line (DSL) Access Multiplexer). Please refer to RFC 2364 for more
information on PPPoA. Refer to RFC 1661 for more information on PPP.
6.5.1.4 RFC 1483
RFC 1483 describes two methods for Multiprotocol Encapsulation over ATM
Adaptation Layer 5 (AAL5). The first method allows multiplexing of multiple
protocols over a single ATM virtual circuit (LLC-based multiplexing) and the
second method assumes that each protocol is carried over a separate ATM virtual
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P-2612HW-F1 User's Guide