User's Manual

Chapter 6 Broadband

P-873HNUP-51B User’s Guide

WAN IP Address

The WAN IP address is an IP address for the ZyXEL Device, which makes it accessible from an

outside network. It is used by the ZyXEL Device to communicate with other devices in other

networks. It can be static (fixed) or dynamically assigned by the ISP each time the ZyXEL Device

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 encapsulation

method).

ATM

Asynchronous Transfer Mode (ATM) is a LAN and WAN networking technology that provides high-

speed data transfer. ATM uses fixed-size packets of information called cells. With ATM, a high QoS

(Quality of Service) can be guaranteed. ATM uses a connection-oriented model and establishes a

virtual circuit (VC) between two endpoints before the actual data exchange begins.

PTM

Packet Transfer Mode (PTM) is packet-oriented and supported by the VDSL2 standard. In PTM,

packets are encapsulated directly in the High-level Data Link Control (HDLC) frames. It is designed

to provide a low-overhead, transparent way of transporting packets over DSL links, as an

alternative to ATM.

Multicast

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

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.

Finding Out More

See Section 6.4 on page 82 for technical background information on WAN.

6.1.2 Before You Begin

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

information from your ISP.