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Chapter 33.
Multicast Configuration
Introduction
The chapter describes peculiarities of IPTV service configuration.
Hosts and routers use the Internet Group Management Protocol (IGMP) to support multicasting.
It provides all systems of a physical network with relevant information: which hosts are included in groups
and which group corresponds to a host.
IGMP snooping is a technique that allows network devices of the channel level (switches) to snoop IGMP
requests from hosts to a group router in order to decide whether group traffic transmission to the
corresponding interfaces should be started or stopped. When a switch snoops a host's IGMP request for
connection to a multicast group, it adds the port the host is connected to into the group (for group traffic
retranslation). And vice versa, having snooped a leave_group request, the switch removes the corresponding
port from the group.
Fig. 33.1 – IGMP Snooping Is Disabled
Fig. 33.1 shows traffic multicasting regardless of whether an end host needs the traffic or not. When
IGMP snooping is enabled, the multicasting situation changes as follows: the switch will analyse all IGMP
packets between connected devices and the routers the multicast traffic comes from. When the switch
receives a consumer's IGMP request for connection to a multicast group, it adds the port the consumer is
connected to into the group. And vice versa, having received a request for leaving a group, the switch
removes the corresponding port from the group.
Summary of Contents for LTP-4X
Page 11: ...11 Part I General ...
Page 29: ...29 Part II Getting Started with the Terminal ...
Page 37: ...37 Part III Configuring the Terminal ...
Page 98: ...98 Part IV ONT Configuration ...
Page 174: ...174 Part V Terminal Monitoring ...
Page 189: ...189 Part VI Terminal Maintenance ...
Page 191: ...191 Step 2 Remove the module from the slot Fig 43 4 Removing SFP Transceivers ...
