ZyXEL Communications Prestige 652, User Manual, Page: 54 / 521

Prestige 652 Series User’s Guide
3-2 Wizard Setup
3.2.4 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
circuit (VC-based multiplexing). Please refer to the RFC for more detailed information.
3.3 Multiplexing
There are two conventions to identify what protocols the virtual circuit (VC) is carrying. Be sure to use the
multiplexing method required by your ISP.
3.3.1 VC-based Multiplexing
In this case, by prior mutual agreement, each protocol is assigned to a specific virtual circuit; for example,
VC1 carries IP, etc. VC-based multiplexing may be dominant in environments where dynamic creation of
large numbers of ATM VCs is fast and economical.
3.3.2 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, for example, if charging heavily depends on
the number of simultaneous VCs.
3.4 VPI and VCI
Be sure to use the correct Virtual Path Identifier (VPI) and Virtual Channel Identifier (VCI) numbers
assigned to you. The valid range for the VPI is 0 to 255 and for the VCI is 32 to 65535 (0 to 31 is reserved
for local management of ATM traffic). Please see the
appendices for more information.
3.5 Wizard Setup Configuration: First Screen
In the SITE MAP screen click Wizard Setup to display the first wizard screen.