ZyXEL P-663H-51 Guia Do Utilizador

P-663H-51 User’s Guide

This chapter describes how to configure WAN settings.

A WAN (Wide Area Network) is an outside connection to another network or the Internet.

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 appendix for 
more information.

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.

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.

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.

Traffic shaping is an agreement between the carrier and the subscriber to regulate the average 
rate and fluctuations of data transmission over an ATM network. This agreement helps 
eliminate congestion, which is important for transmission of real time data such as audio and 
video connections.