Vc-Based Multiplexing; Llc-Based Multiplexing; Encapsulation; Enet Encap - ZyXEL Communications Prestige 642 User Manual

3.7.1

VC-based multiplexing

In this case, by prior mutual agreement, each protocol is assigned to a specific virtual circuit, e.g., VC1
carries IP, VC2 carries IPX, etc. VC-based multiplexing may be dominant in environments where dynamic
creation of large numbers of ATM VCs is fast and economical.
3.7.2

LLC-based multiplexing

In this case one VC carries multiple protocols with protocol identifying information being contained in each
packet header. Despite the extra bandwidth and processing overhead, this method may be advantageous if it
is not practical to have a separate VC for each carried protocol, e.g., if charging heavily depends on the
number of simultaneous VCs.
3.8

Encapsulation

Be sure to use the encapsulation method required by your ISP. The Prestige supports the following
methods.
3.8.1

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 i.e., it encapsulates routed Ethernet frames into
bridged ATM cells. ENET ENCAP requires that you specify a gateway IP address in the Ethernet
Encapsulation Gateway field in Menu 4 and in the Rem IP Addr field in Menu 11.1. You can get this
information from your ISP.
3.8.2

PPP

Please refer to RFC 2364 for more information on PPP over ATM Adaptation Layer 5 (AAL5). Refer to
RFC 1661 for more information on PPP.
3.8.3

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
circuit (VC-based multiplexing). Please refer to the RFC for more detailed information.
3.9

IP Address Assignment

A static IP is a fixed IP that your ISP gives you. A dynamic IP is not fixed. The ISP assigns you a different
one each time. The Single User Account feature can be enabled or disabled no matter whether you have a
dynamic or static IP. However the encapsulation method assigned influences your choices for IP Address
and ENET ENCAP Gateway.
Internet Access
Prestige 642 ADSL Internet Access Router
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