ZyXEL Communications ADSL2+4 用户手册

Chapter 6 WAN Setup

P-660H-T1v3s User’s Guide

Encapsulation is used to include data from an upper layer protocol into a lower 
layer protocol. To set up a WAN connection to the Internet, you need to use the 
same encapsulation method used by your ISP (Internet Service Provider). If your 
ISP offers a dial-up Internet connection using PPPoE (PPP over Ethernet) or PPPoA, 
they should also provide a username and password (and service name) for user 
authentication.

The WAN IP address is an IP address for the P-660H-T1v3s, which makes it 
accessible from an outside network. It is used by the P-660H-T1v3s to 
communicate with other devices in other networks. It can be static (fixed) or 
dynamically assigned by the ISP each time the P-660H-T1v3s tries to access the 
Internet.

If your ISP assigns you a static WAN IP address, they should also assign you the 
subnet mask and DNS server IP address(es) (and a gateway IP address if you use 
the Ethernet or ENET ENCAP encapsulation method).

Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 
sender - 1 recipient) or Broadcast (1 sender - everybody on the network). 
Multicast delivers IP packets to a group of hosts on the network - not everybody 
and not just one.

IGMP (Internet Group Multicast Protocol) is a network-layer protocol used to 
establish membership in a Multicast group - it is not used to carry user data. 
There are three versions of IGMP. IGMP version 2 and 3 are improvements over 
version 1, but IGMP version 1 is still in wide use.

See 

 for technical background information on WAN.

You need to know your Internet access settings such as encapsulation and WAN IP 
address. Get this information from your ISP.