ZyXEL 791R 91-004-247001B Manual Do Utilizador

 

 

Prestige 791R G.SHDSL Router 

Internet Access 

 

7-3 

as a DHCP client on the WAN port and so the IP Address and ENET ENCAP Gateway fields are not 
applicable (N/A) as they are assigned to the Prestige by the DHCP server. 

Be sure to use the correct Virtual Path Identifier (VPI) and Virtual Channel Identifier (VCI) numbers 
supplied by your telephone company.  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. 

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 
“burstiness” or fluctuation 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.