ZyXEL Communications P-660N-T1A, User Manual

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Chapter 6 WAN Setup
P-660N-T1A User’s Guide
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method assumes that each protocol is carried over a separate ATM virtual circuit
(VC-based multiplexing). Please refer to RFC 1483 for more detailed information.
6.4.2 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.
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.
6.4.3 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.
6.4.4 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.