ZyXEL nbg-5715 Guia Do Utilizador

 Chapter 10 WAN

NBG5715 User’s Guide

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 1. 

Multicast Example

In the multicast example above, systems A and D comprise one multicast group. In multicasting, 
the server only needs to send one data stream and this is delivered to systems A and D. 

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. The NBG5715 supports both IGMP version 1 
(IGMP-v1) and IGMP version 2 (IGMP-v2). 

At start up, the NBG5715 queries all directly connected networks to gather group membership. 
After that, the NBG5715 periodically updates this information. IP multicasting can be enabled/
disabled on the NBG5715 LAN and/or WAN interfaces in the Web Configurator (LAN; WAN). Select 
None to disable IP multicasting on these interfaces.

Use this screen to change your NBG5715’s Internet access settings. Click Configuration > 
Network > WAN to open the Broadband screen. The screen differs according to the 
encapsulation you choose.