Vpi And Vci; Ip Address Assignment; Nailed-Up Connection (Ppp) - ZyXEL Communications P-660W-Tx User Manual

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.
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.

7.5.3 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 appendix for
more information.

7.5.4 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 if you
have either a dynamic or static IP. However the encapsulation method assigned influences
your choices for IP address and ENET ENCAP gateway.
IP Assignment with PPPoA or PPPoE Encapsulation
If you have a dynamic IP, then the IP Address and Gateway IP Address fields are not
applicable (N/A). If you have a static IP, then you only need to fill in the IP Address field and
not the Gateway IP Address field.
IP Assignment with RFC 1483 Encapsulation
In this case the IP address assignment must be static.
IP Assignment with ENET ENCAP Encapsulation
In this case you can have either a static or dynamic IP. For a static IP you must fill in all the IP
Address and Gateway IP Address fields as supplied by your ISP. However for a dynamic IP,
the ZyXEL Device acts as a DHCP client on the WAN port and so the IP Address and
Gateway IP Address fields are not applicable (N/A) as the DHCP server assigns them to the
ZyXEL Device.

7.5.5 Nailed-Up Connection (PPP)

A nailed-up connection is a dial-up line where the connection is always up regardless of traffic
demand. The ZyXEL Device does two things when you specify a nailed-up connection. The
first is that idle timeout is disabled. The second is that the ZyXEL Device will try to bring up
the connection when turned on and whenever the connection is down. A nailed-up connection
can be very expensive for obvious reasons.
P-660W-Tx v2 User's Guide
Chapter 7 WAN Setup
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